• TABLE OF CONTENTS
HIDE
 Front Cover
 Abstract
 Title Page
 About the authors
 Table of Contents
 Foreword
 Preface
 Summary
 Background on maize
 International germplasm development...
 Recent releases and use of improved...
 Summary of use of improved...
 Reference
 Appendix A: A note on some maize...
 Appendix B: Yield potential of...
 Back Cover






Title: Development and spread of improved maize varieties and hybrids in developing countries
CITATION PAGE IMAGE ZOOMABLE PAGE TEXT
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00053933/00001
 Material Information
Title: Development and spread of improved maize varieties and hybrids in developing countries
Physical Description: xi, 71 p. : ill. ; 28 cm.
Language: English
Creator: Timothy, David H ( David Harry )
Harvey, Paul Henry, 1911-
Dowswell, Christopher R.
United States -- Agency for International Development. -- Bureau for Science and Technology
Publisher: Bureau for Science and Technology, Agency for International Development
Place of Publication: Washington DC
Publication Date: 1988
 Subjects
Subject: Corn -- Breeding -- International cooperation -- Developing countries   ( lcsh )
Hybrid corn -- International cooperation -- Developing countries   ( lcsh )
Genre: federal government publication   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references.
Statement of Responsibility: David H. Timothy, Paul H. Harvey, and Christopher R. Dowswell.
Funding: Electronic resources created as part of a prototype UF Institutional Repository and Faculty Papers project by the University of Florida.
 Record Information
Bibliographic ID: UF00053933
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 19287757

Table of Contents
    Front Cover
        Front Cover
    Abstract
        Abstract
    Title Page
        Page i
    About the authors
        Page ii
    Table of Contents
        Page iii
        Page iv
    Foreword
        Page v
        Page vi
    Preface
        Page vii
        Page viii
    Summary
        Page ix
        Page x
        Page xi
    Background on maize
        Page 1
        Page 2
        Maize in the world economy
            Page 1
            Area and production
                Page 1
            Utilization
                Page 1
                Page 2
        Some basic biological characteristics of maize
            Page 3
            Botanical classification
                Page 3
            Climatic adaptation
                Page 3
        Influences on maize improvement
            Page 3
            Selection criteria and plant structure
                Page 3
            Selection criteria and use
                Page 3
            Selection criteria and population structure
                Page 4
            Infrastructure and plant breeding
                Page 4
                Page 5
                Page 6
    International germplasm development programs and networks
        Page 7
        Early maize germplasm
            Page 7
            Germplasm collections in Latin America
                Page 7
            Development of improved varieties and hybrids in Latin America
                Page 8
            Maize research activities in Asia
                Page 9
            Exchanges of breeding material and informal cooperative networks
                Page 10
            Emerging concepts of germplasm use and breeding methods
                Page 10
            Refinement of population improvement methods
                Page 11
        Establishment of international maize improvement programs
            Page 11
            Page 12
            CIMMYT's international maize improvement program
                Page 13
                Page 14
            IITA's maize improvement program
                Page 15
                Page 16
                Page 17
                Page 18
    Recent releases and use of improved maize materials
        Page 19
        Page 20
        Sub-Saharan Africa
            Page 19
            Eastern and Southern Africa
                Page 19
                Ethiopia
                    Page 19
                Kenya
                    Page 19
                Lesotho
                    Page 21
                Malawi
                    Page 21
                    Page 22
                Mozambique
                    Page 23
                Reunion
                    Page 23
                South Africa
                    Page 23
                Somalia
                    Page 24
                    Page 25
                Swaziland
                    Page 24
                Tanzania
                    Page 24
                Uganda
                    Page 26
                    Page 27
                Zambia
                    Page 26
                Zimbabwe
                    Page 26
            Western and Central Africa
                Page 28
                Benin
                    Page 28
                Burkina Faso
                    Page 28
                Cameroon
                    Page 28
                Central African Republic
                    Page 28
                Cote D'Ivoire
                    Page 28
                Gambia
                    Page 29
                Ghana
                    Page 29
                Liberia
                    Page 29
                Nigeria
                    Page 30
                Senegal
                    Page 30
                Sierra Leone
                    Page 31
                Togo
                    Page 31
                Zaire
                    Page 31
        North Africa and the Middle East
            Page 32
            North Africa and the Middle East
                Page 32
                Egypt
                    Page 32
                Morocco
                    Page 32
            Middle East
                Page 33
                Turkey
                    Page 33
        Asia
            Page 34
            South Asia
                Page 34
                Burma
                    Page 34
                India
                    Page 34
                Nepal
                    Page 35
                Pakistan
                    Page 36
                Sri Lanka
                    Page 37
            Southeast Asia and Pacific
                Page 38
                Indonesia
                    Page 38
                Phiippines
                    Page 38
                Thailand
                    Page 39
                    Page 40
                Vietnam
                    Page 41
            East Asia
                Page 41
                China
                    Page 41
        Latin America
            Page 42
            Mexico, Central America, and Caribbean
                Page 42
                Costa Rica
                    Page 42
                Cuba
                    Page 42
                El Salvador
                    Page 42
                Guatemala
                    Page 43
                Haiti
                    Page 44
                    Page 45
                Honduras
                    Page 44
                Mexico
                    Page 44
                Nicaragua
                    Page 46
                Panama
                    Page 46
            Andean region, South America
                Page 46
                Bolivia
                    Page 46
                Colombia
                    Page 46
                Ecuador
                    Page 47
                Peru
                    Page 48
                Venezuela
                    Page 49
            Southern cone, South America
                Page 49
                Argentina
                    Page 49
                Brazil
                    Page 49
                Chile
                    Page 50
                Paraguay
                    Page 51
                    Page 52
    Summary of use of improved genotypes
        Page 53
        Cimmyt survey of improved maize seed use
            Page 53
        Regional totals
            Page 54
            Eastern and southern Africa
                Page 55
                Page 56
            West and central Africa
                Page 57
            North Africa and the Middle East
                Page 57
            South Asia
                Page 58
            Southeast Asia and the Pacific
                Page 58
            East Asia
                Page 59
            Meixco, Central America, and the Caribbean
                Page 59
            Andean countries of South America
                Page 60
            Southern cone countries of South America
                Page 61
            Accelerating the use of improved maize genotypes in the Third World
                Page 61
                Page 62
    Reference
        Page 63
        Published references
            Page 63
            Page 64
            Page 65
        Correspondence and interviews
            Page 66
        Manuscript reviews
            Page 67
            Page 68
    Appendix A: A note on some maize breeding terms
        Page 69
        Page 70
    Appendix B: Yield potential of tropical hybrids in the United States
        Page 71
    Back Cover
        Back Cover
Full Text

Development and Spread of'
Improved Maize Varieties and Hybridse
in Developing Countries


Development


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ABSTRACT


Maize is the third most important cereal crop in the developing world,
after rice and wheat. Attempts have been made over many years to improve
maize varieties and hybrids used in developing countries. National and inter-
national programs have been involved. In the latter case, research has been
concentrated at the International Maize and Wheat Improvement Center
(CIMMYT) in Mexico and the International Institute of Tropical Agriculture
(IITA) in Nigeria. Both centers carry out their work in collaboration with
national research programs.
Although the adoption of high-yielding wheat varieties developed by
CIMMYT and of rice varieties developed by other centers has been well doc-
umented, the same is not true of maize. Part of the reason is that the genetics
of maize are quite different from, and much more complicated than, wheat or
rice. Improved varieties are not as easily identified visually. Also, relatively
little effort has been put into the measurement process. As a result, it is not
well known how much impact the maize research programs have had at the
farm level.
This report is a first step in rectifying this information gap. It attempts to
identify the maize varieties, hybrids, population, pools, and lines developed by
CIMMYT and IITA that are being used in national programs in developing
nations. It also incorporates, where available, estimates of area planted with
hybrids and improved varieties. Further work is needed to more fully docu-
ment the main gene pools and to verify and expand the statistical data at the
national level.




Key Words
Maize, corn, maize/corn breeding, maize/corn varieties and hybrids, agri-
cultural research, international agricultural research centers, developing
countries


Cover photograph from CIMMYT

















DEVELOPMENT AND SPREAD OF
IMPROVED MAIZE VARIETIES AND HYBRIDS
IN DEVELOPING COUNTRIES







David H. Timothy, Paul H. Harvey, and
Christopher R. Dowswell


Bureau for Science and Technology
Agency for International Development
Washington, DC
1988


'i(ll'',















ABOUT THE AUTHORS


David H. Timothy is Professor of Crop Science, Botany, and Genetics at North Carolina
State University, Raleigh. He served as a plant geneticist for the Rockefeller Foundation in
Bogota, Colombia, from 1956 to 1961, where he headed the Cooperative Maize Improvement
Program of the Foundation and the Ministry of Agriculture. He also worked closely with
maize improvement programs in other Latin American countries. During 1985-86, Dr.
Timothy was Chief Scientist of the U.S. Department of Agriculture's Competitive Research
Grant Program in Washington, D.C.
Paul H. Harvey was William Neal Reynolds Professor and head of the Crop Science
Department at North Carolina State University, Raleigh, until his retirement in 1975. He
then served as coordinator of corn, grain sorghum, and grain millet for the National Program
Staff of the Agricultural Research Service (ARS) of the U.S. Department of Agriculture in
Beltsville, Maryland, until 1980. In the early 1980s, Dr. Harvey served as coordinator for the
National Corn Research Needs and Priorities Study. In addition to his domestic work in corn
breeding, he has served as a consultant overseas.
Christopher R. Dowswell is a consultant in agricultural communications residing in Mex-
ico. He is currently coauthoring a book titled Maize in the Developing World: A Handbook for
Research Administrators. He was formerly head of Information Services at the International
Maize and Wheat Improvement Center (CIMMYT) from 1978 to 1985, and at the Interna-
tional Fertilizer Development Center (IFDC) from 1976 to 1978. He also worked as an
extension agent and communications specialist for Oregon State University during 1973 to
1976.



DISCLAIMER

The views expressed in this bulletin are those of the authors and are not necessarily those
of the U.S. Agency for International Development. Mention of commercial firms and/or
their products does not constitute or imply endorsement.







Publication development services provided by
METROTEC, Inc.
Washington, D.C.

















Contents


Foreword v
Preface vii
Summary ix


1. Background on Maize 1
Maize in the World Economy 1
Area and production 1 Utilization 1
Some Basic Biological Characteristics of Maize 3
Botanical classification 3 Climatic adaptation 3
Influences on Maize Improvement 3
Selection criteria and plant structure 3 Selection criteria and use 3 Selection
criteria and population structure 4 Infrastructure and plant breeding 4

2. International Germplasm Development Programs and Networks 7
Early Maize Germplasm Efforts and Approaches 7
Germplasm collections in Latin America 7 Development of improved varieties
and hybrids in Latin America 8 Maize research activities in Asia 9
Exchanges of breeding material and informal cooperative networks 10
Emerging concepts of germplasm use and breeding methods 10
Refinements of population improvement methods 11
Establishment of International Maize Improvement Programs 11
CIMMYT's international maize improvement program 13
IITA's maize improvement program 15

3. Recent Releases and Use of Improved Maize Materials 19
Sub-Saharan Africa 19
Eastern and Southern Africa 19
Ethiopia 19 Kenya 19 Lesotho 21 Malawi 21 Mozambique 23
Reunion 23 South Africa 23 Somalia 24 Swaziland 24 Tanzania 24
Uganda 26 Zambia 26 Zimbabwe 26
Western and Central Africa 28
Benin 28 Burkina Faso 28 Cameroon 28 Central African Republic 28
Cote d'Ivoire 28 Gambia 29 Ghana 29 Liberia 29 Nigeria 30
Senegal 30 Sierra Leone 31 Togo 31 Zaire 31










North Africa and the Middle East 32
North Africa 32
Egypt 32 Morocco 32
Middle East 33
Turkey 33
Asia 34
South Asia 34
Burma 34 India 34 Nepal 35 Pakistan 36 Sri Lanka 37
Southeast Asia and Pacific 38
Indonesia 38 Philippines 38 Thailand 39 Vietnam 41
East Asia 41
China 41
Latin America 42
Mexico, Central America, and Caribbean 42
Costa Rica 42 Cuba 42 El Salvador 42 Guatemala 43 Haiti 44
Honduras 44 Mexico 44 Nicaragua 46 Panama 46
Andean Region, South America 46
Bolivia 46 Colombia 46 Ecuador 47 Peru 48 Venezuela 49
Southern Cone, South America 49
Argentina 49 Brazil 49 Chile 50 Paraguay 51

4. Summary of Use of Improved Genotypes 53
CIMMYT Survey of Improved Maize Seed Use 53
Regional Totals 54
Eastern and Southern Africa 55 West and Central Africa 57 North Africa a
the Middle East 57 South Asia 58 Southeast Asia and the Pacific 58
East Asia 59 Mexico, Central America, and the Caribbean 59 Andean
countries of South America 60 Southern Cone countries of South America 61
Accelerating the Use of Improved Maize Genotypes in the Third World 61

References 63
Published References 63
Correspondence and Interviews 66
Manuscript Reviews 67

Appendix A. A Note on Some Maize Breeding Terms 69

Appendix B. Yield Potential of Tropical Hybrids in the United States 71

















Foreword


This report had its origins in late 1983. At that time, the Consultative Group on Interna-
tional Agricultural Research (CGIAR) organized an Impact Study of the research it had
sponsored in developing nations. As part of the commodity portion of that effort, there was
interest in initiating a study on the development and adoption of improved maize germplasm.
There was good reason for this interest. Maize is a major crop in developing countries,
and it represents a major line of activity at two centers sponsored by the CGIAR-the Inter-
national Maize and Wheat Improvement Center (CIMMYT) in Mexico and the International
Institute for Tropical Agriculture (IITA) in Nigeria. While research on maize has been
underway at both centers since their inception, relatively little has been done to trace the
adoption and use of maize technology produced by these centers in cooperation with national
programs.
The Agency for International Development was requested to provide some in-kind assis-
tance to the CGIAR Impact Study. I was asked to update my earlier studies on the develop-
ment and spread of high-yielding varieties of wheat and rice (Dalrymple 1986a,b) and some
thought was given to having me initiate a similar effort on maize. The latter step, it quickly
became apparent, was not possible-both because of time constraints and the need for tech-
nical knowledge of maize genetics and breeding. Hence, it was decided to contract the maize
portion to a maize specialist. Dr. Nyle C. Brady, A.I.D.'s Senior Assistant Administrator for
Science and Technology, was keenly interested in initiating the work and saw to it that the
necessary financial resources were available for the study. The Office of International Coop-
eration and Development of the U.S. Department of Agriculture assisted in the search and
engagement of suitable individuals to carry out the work.
Arrangements were made with Drs. David Timothy and Paul Harvey of North Carolina
State University in the spring of 1984 to initiate the work. They produced a first draft by early
1986 (Dr. Timothy was primarily responsible for chapters 1 and 2 and Dr. Harvey for chapter
3). The manuscript was then distributed for technical review. In the course of this process, a
considerable amount of new country information became available, principally from
CIMMYT, but also from IITA and the CGIAR Impact Study itself. Unfortunately, by then,
the authors had used up the time they had available for the project.
Christopher Dowswell, formerly head of the CIMMYT information office and now a con-
sultant in agricultural communications, was subsequently engaged to incorporate this new
information. He started work in early 1987 and acquired additional information from
CIMMYT and IITA personnel and from national maize researchers in several Asian and
African countries in the course of travels to those nations on other assignments. He also
interacted with Drs. Timothy and Harvey. The revised manuscript was then reviewed again
and further modifications were made; this process was completed by June 1988.
Thus, the final report is the product of a two-stage process stretching over 4 years. I think
that the two stages-involving individuals with different backgrounds-introduced some
"hybrid vigor" into the report. This vigor has been needed because of the pioneering and dif-
ficult nature of the enterprise. We now better understand why it has not been done before.
At the same time, we recognize the importance of the task and the need to record some of
the information before it disappears.










There is, inevitably, some unevenness in the country coverage in the report. Principal
emphasis is placed on the distribution and use of germplasm provided by CIMMYT and
IITA. Obviously, the related contributions of national programs would be given further
attention in a more comprehensive treatment. More is also said about public rather than pri-
vate research efforts. This is because most maize research in developing countries has been
conducted by public-sector organizations and because less information is available from
private-sector organizations on the genetic resources used in genotype development. Areas
where the private sector is particularly active, such as the Southern Cone of South America,
are not covered to the extent that their importance in maize production might have sug-
gested. This is particularly true of Argentina, for which very little information is reported.
Africa, on the other hand, receives extensive coverage-reflecting the extent to which maize
improvement research is a public sector effort and, in part, the large number of countries
with maize research programs.
The country presentations are, in any case, quite brief and tend to focus on the develop-
ment and commercial release of improved varieties and hybrids rather than the actual cover-
age and impact on yields of these improved genotypes at the farm level. In most cases, it has
not been possible to provide much statistical information, particularly of a time-series nature,
about the area planted with improved maize varieties and hybrids in individual countries.
The uninitiated might tend to think of maize breeding as a passionless, scientific enter-
prise. It certainly is scientific, but there are-as when one scratches the surface in other
areas-strong differences in opinion among some scientists. The study attempted to strike a
middle ground and stay with the facts as closely as possible.
There is plenty of work left to do-both to expand the breadth and depth of the coverage.
I hope that this report serves both as an introduction to the subject and as a stimulus for
further study.

Dana G. Dalrymple
Project Advisor
Directorate for Food and Agriculture
Bureau for Science and Technology

















Preface


This first report on the development and use of improved maize genotypes in the Third
World is modeled after the reports prepared periodically by Dana G. Dalrymple on the
development and spread of high-yielding varieties of wheat and rice in the less developed
nations (Dalrymple 1986a,b). While we are disappointed that this report is not as complete in
scope or data coverage as those reports, we are pleased in the belief that it will be a useful
resource for subsequent efforts.
Our original hope was to obtain reasonably accurate estimates of the use of improved,
specifically identified germplasm, varieties, or hybrids emanating from the International
Maize and Wheat Improvement Center, headquartered in Mexico and commonly known by
its Spanish acronym, CIMMYT, and the International Institute of Tropical Agriculture
(IITA), headquartered in Nigeria.
We planned to establish the genealogies of the varieties, hybrids, populations, pools, and
lines being developed by these two international agricultural research centers. Having the
known genealogies in hand would permit (1) more reliable estimates of the germplasm con-
tribution of these two IARCs to national program efforts to increase maize production in the
Third World, (2) more definitive concepts of which basic germplasm is most noteworthy in
that production, and, perhaps, (3) identification of basic germplasm that might receive more
attention in future maize improvement strategies.
The peculiar (as opposed to wheat or rice) characteristics of maize biology and its culture
have complicated efforts to provide an accurate picture of the use of improved varieties and
hybrids in developing countries. Nonetheless, we have assembled a sizable amount of anec-
dotal information, oral histories, copies of lists and unpublished reports, and copies of
genealogies and pedigrees made from field books about breeding material extracted from, or
combined with, other germplasm. But informative and fascinating as these particulars
appear, their range in accuracy, completeness, precision, and scope will require additional
investigation. Subsequent efforts might well concentrate on ferreting out more reliable
information on cultivars or material being developed having known genetic relationships to
germplasm from the IARCs.
There is a particularly strong need to investigate the origins and breeding methodologies
used to develop the outstanding germplasm complexes that have contributed so much to the
improvement of maize. Many of the detailed records on how these germplasm complexes
were put together and what mating and selection systems were employed are still available
from field books and unpublished reports. Some of the details are missing, however, and
attainable only from those researchers and breeders who put the materials together in the
first place. Many of these people have retired and some have died. Thus, it is unlikely that
the necessary records about the origins and handling of these germplasm complexes will be
preserved much longer. If the formation of these outstanding gene pools and populations and
the methodologies used to improve them are to be documented, it must be done promptly.
The original draft of this study has been considerably modified through the additional
information and comments provided by CIMMYT and IITA and by several national maize
programs in Asia, the Middle East, and Africa. Several CIMMYT and IITA maize publica-
tions released in 1986 and 1987 have provided new information on germplasm development










in developing countries. National production statistics published by FAO have been added in
chapters 1 and 4. The statistics on the use of improved genotypes come from a CIMMYT
survey conducted in 1985-86 on commercial seed production in developing countries
(CIMMYT 1987). Even with these data additions, there is still inadequate information on
germplasm development and use for many countries.
Numerous maize researchers in developing and developed countries have given gener-
ously of their time in interviews and correspondence. We are most grateful to them. Various
drafts of this report were reviewed by research leaders at CIMMYT, IITA, and several pri-
vate plant breeding companies. To them we extend our profound thanks. A special expres-
sion of gratitude goes to Dana G. Dalrymple for his encouragement, guidance, and thoughts
throughout this project.

David H. Timothy
Paul H. Harvey
Christopher R. Dowswell

















Summary


Maize is the second most important cereal crop in the world overall, after wheat and
before rice. In the developing world, maize ranks third, after rice and wheat. In total, there
are 80 million ha planted with maize in developing countries. This represents 60% of the
world's maize area, though only 40% of global production is harvested from Third World
maize lands. Tropical and subtropical environments cover 65% to 70% of this area and tem-
perate environments cover the remainder. Four countries account for 67% of total Third
World maize production: China, Brazil, Mexico, and Argentina.
The biology of maize and its population structure are vastly distinct from those of wheat
and rice. The ramifications of these differences are reflected in (1) the use of breeding mate-
rials and methodologies, (2) technology and capability of seed production and distribution,
and (3) local customs and conditions pertinent to grain production and consumer uses of
maize. Improvement of maize germplasm for local, national, or international programs may
be accomplished by emphasis on population improvement, concentration on hybrids and
inbred lines, or modifications of either or both approaches.
Maize research in developing countries received an important impetus from the collabo-
rative maize improvement programs established during the 1940s and 1950s by the Rocke-
feller Foundation and the governments of various developing countries. One of the first
maize research efforts supported by the Rockefeller Foundation was the collection, classifi-
cation, and preservation of the native maize races in Latin America and the
Caribbean-centers of origin for maize. The best germplasm collections were assembled into
breeding populations and improved for yield and various agronomic traits; these populations
were then shared with selected national programs in the Americas, Asia, and Africa. A
handful of these germplasm complexes introduced substantial new amounts of useful genetic
diversity into national maize research programs, especially in Asia and Africa, where the
genetic base of national breeding materials had become very narrow. These germplasm
introductions accelerated progress in many maize breeding programs, and literally hundreds
of improved varieties and hybrids have been developed using germplasm obtained through
international exchange.
The International Maize and Wheat Improvement Center (CIMMYT) and the Interna-
tional Institute of Tropical Agriculture (IITA), established in the mid-1960s, represent the
"institutionalization" of many of the international research and training activities pioneered
during the 1940s and 1950s by the Rockefeller and Ford Foundations, FAO, and USAID.
During the past two decades, the international agricultural research center (IARC) system
has greatly expanded the amount and scope of international agricultural research. Similarly,
developing countries, impressed by the green revolution gains in wheat and rice, have
markedly expanded their investments in national agricultural research systems, including
maize improvement research.
Today, CIMMYT and IITA serve as research hubs of large maize improvement networks
involving hundreds of maize scientists in over 100 developing countries. Both IARCs operate
large (and growing) maize research programs. Through international testing programs, vast
amounts of improved maize germplasm are distributed for evaluation and use by national
breeding programs. Each year, tons of seed for experimentation are shipped by CIMMYT










and IITA to hundreds of national collaborators throughout the world. Both IARCs make
their seed freely available to bona fide maize researchers; preference, however, is given to
collaboration with public sector maize research organizations. Of the two IARCs, CIMMYT
has the most widespread maize improvement program, with collaborative relationships with
more than 80 countries in Latin America, Asia, and Africa. IITA has maintained a regional
focus in its maize improvement work, concentrating on the germplasm requirements of
sub-Saharan Africa.
The complex genetic backgrounds of the new maize types developed, or being developed,
preclude a simplistic compilation of data that would attribute increased yield or production
to the use of CIMMYT and IITA materials. The improved maize germplasms developed
and/or distributed by CIMMYT and IITA do not have a single common characteristic-such
as the dwarfing habit so obvious in rice and wheat-to facilitate the tracking of production
data. Even so, this report shows that developing countries have released hundreds of varieties
and hybrids based on CIMMYT and IITA germplasm, with CIMMYT being a more domi-
nant germplasm contributor. IITA's streak-resistant germplasm has been extremely valuable
to national maize programs, especially in sub-Saharan Africa. Some of IITA's tropical inbred
lines and hybrids are also showing promise in maize production zones in sub-Saharan Africa
and on other continents. In some instances, increased production from the use of CIMMYT
and IITA maize stocks has been noteworthy. In other cases, the results are nebulous at best.
In the temperate areas and, to some extent, in the subtropical areas of the developing
world, germplasm from the USA and Europe has been widely used to develop improved
genotypes. In the subtropical areas, however, temperate germplasnr has generally lacked suf-
ficient resistance to stalk and ear rots and various foliar diseases. To overcome this defi-
ciency, tropical and subtropical germplasms with greater resistance to these diseases have
been introgressed to strengthen the disease resistance of genotypes based on temperate
germplasm.
Improved genotypes have been developed and released for most lowland tropical and
subtropical areas of the developing world. These materials have higher yield potential and
superior agronomic characteristics than traditional maize varieties. The improved genotypes
are shorter in stature than traditional local materials and partition more of their total dry
matter production to grain. Their resistance to foliar diseases and stalk and ear rots is also
generally superior to traditional varieties. There is still a need to develop genotypes for
intermediate and highland environments and for those areas characterized by serious envi-
ronmental stresses, especially drought.
CIMMYT has estimated that in 1985-86 approximately 50% of 80 million ha in develop-
ing countries was planted with commercial seed of improved hybrids and improved varieties.
In China, Brazil, and Argentina-which have 30 million ha of maize land-commercial seed
is used on over 75% of the total maize areas. However, when these three countries are not
included in the statistics, only about 26% of the total maize area in developing countries is
planted with commercial varieties and hybrids. While improved genotypes have been devel-
oped that are suitable for much of the area still growing local varieties and landraces, other
impediments-especially nonavailability of commercial seed and fertilizer-restrict their
adoption.
Although improved genotypes have been developed and released for most of the major
production environments, the absence of effective seed production systems has seriously
restricted the diffusion of these materials at the farm level. Unfortunately, in all too many
countries, the absence of functioning maize seed sectors has severely restricted the diffusion
of improved varieties and hybrids at the farm level. This, in turn, has seriously reduced the
returns that would have otherwise accrued to society from the investments made by devel-
oping country governments in maize improvement research. Clearly, nonfunctioning maize










seed sectors in all too many developing countries have had a tremendous cost in terms of
foregone maize production and improvements in productivity.
Since the late 1970s, private sector involvement in maize research and seed production in
the developing world has grown markedly. Initially, private maize seed companies concen-
trated their activities in temperate-zone developing countries where U.S. Corn Belt hybrids
do well. Increasingly, however, as more improved germplasm for tropical and subtropical
areas has become available (developed largely through national and international public
sector research efforts), private sector maize research and seed production initiatives have
expanded in those countries with subtropical and tropical maize production environments
where strong commercial demand exists for maize.



















1. BACKGROUND ON MAIZE


MAIZE IN THE WORLD
ECONOMY

Area and Production
Maize, with a global harvest in 1985 of 449 million
metric tons from 133 million ha, ranked second to
wheat (with hulled rice third) among the world's cereal
crops (FAO 1986). Some 70 countries produce maize
on 100,000 ha or more; 53 of these are developing
countries. Developed market economies account for
30% of the global maize area but provide 50% of total
production, due to average yields that are three times
higher than the world average. Developing countries
account for approximately 60% of the total world
maize area but produce only 40% of the global harvest.
During 1983-85, developing countries produced an
average of 169 million tons (t)1 of maize per year
(CIMMYT 1987). Four countries accounted for 67%
of the Third World's maize production: China (68
million t), Brazil (21 million t), Mexico (14 million t),
Argentina (10 million t).
In total, there are 80 million ha planted with maize
in developing countries. Lowland tropical environments
account for 32 million ha or about 40% of the total area
planted with maize in the developing world. These
tropical maize growing environments are found in the
lowlands of eastern and western Africa, south of the
Sahara; the plains and delta areas of South Asia;
Southeast Asia; Central America and parts of Mexico;
and the lowland areas in Andean countries of South
America and Brazil. Temperate environments (e.g.,
Argentina, Chile, China, Middle East), accounting for
24 million ha (30%) of the total maize area, are in
developing countries. Subtropical and intermediate-
elevation zones (South Asia, Middle East, North Africa,
Mexico, Brazil, East Africa) account for approximately
18 million ha (22%) of the developing country maize

1All ton measurements are for metric tons.


area. Highland zones above 1,500 m (subtrop-
ical-temperate) in Mexico, Central America, Andean
countries, East Africa, and Himalayan countries account
for about 6 million ha (8%) of the total maize area in
the Third World.
During the period 1961-65 to 1983-85, world maize
production increased by 182 million t (CIMMYT 1987).
This is a 4.0% annual growth rate and represents a 84%
increase in world supplies. Most of this growth was
achieved through yield improvements. In developing
countries-though there was considerable regional
variation-yields increased at a 2.8% annual rate, while
the overall area expanded by 1.2% per year. China
reported the most rapid growth in yields among major
producers, with a 4.8% per annum rate of gain in yield
per year. In sharp contrast, yields in sub-Saharan
Africa increased at only a 0.9% yearly rate. For the
developing countries as a whole, production is not
increasing as fast as demand, and imports are rising
(Vocke 1987).

Utilization
Maize is used in more ways than any other cereal:
as a human food, a feed grain, a fodder crop, and for
hundreds of industrial purposes. Its grain, stalk, leaves,
cobs, tassel, and silks all have commercial value in most
settings, though that of the grain is the greatest. The
most diversified use of maize occurs in the United
States, where over 1,000 products in a typical super-
market contain maize in some form or another in their
makeup.
Worldwide, about 66% of all maize is used for
feeding livestock, 25% for human consumption, and
9% for industrial purposes and as seed (CIMMYT
1984). In the developing world, however, roughly 50%
of all maize is consumed by humans as a direct food
source, 43% is for livestock feed, and the remainder is
used for industrial and seed purposes (CIMMYT 1984).
Although maize is important as a food crop in Mexico,









IMPROVED MAIZE VARIETIES AND HYBRIDS


-tdL~ -~i;~ T


Figure 1. Cultivating maize interplanted with other crops in Honduras. Source: CIMMYT.


Ilt~L~I~L;EI


-- -A



















1. BACKGROUND ON MAIZE


MAIZE IN THE WORLD
ECONOMY

Area and Production
Maize, with a global harvest in 1985 of 449 million
metric tons from 133 million ha, ranked second to
wheat (with hulled rice third) among the world's cereal
crops (FAO 1986). Some 70 countries produce maize
on 100,000 ha or more; 53 of these are developing
countries. Developed market economies account for
30% of the global maize area but provide 50% of total
production, due to average yields that are three times
higher than the world average. Developing countries
account for approximately 60% of the total world
maize area but produce only 40% of the global harvest.
During 1983-85, developing countries produced an
average of 169 million tons (t)1 of maize per year
(CIMMYT 1987). Four countries accounted for 67%
of the Third World's maize production: China (68
million t), Brazil (21 million t), Mexico (14 million t),
Argentina (10 million t).
In total, there are 80 million ha planted with maize
in developing countries. Lowland tropical environments
account for 32 million ha or about 40% of the total area
planted with maize in the developing world. These
tropical maize growing environments are found in the
lowlands of eastern and western Africa, south of the
Sahara; the plains and delta areas of South Asia;
Southeast Asia; Central America and parts of Mexico;
and the lowland areas in Andean countries of South
America and Brazil. Temperate environments (e.g.,
Argentina, Chile, China, Middle East), accounting for
24 million ha (30%) of the total maize area, are in
developing countries. Subtropical and intermediate-
elevation zones (South Asia, Middle East, North Africa,
Mexico, Brazil, East Africa) account for approximately
18 million ha (22%) of the developing country maize

1All ton measurements are for metric tons.


area. Highland zones above 1,500 m (subtrop-
ical-temperate) in Mexico, Central America, Andean
countries, East Africa, and Himalayan countries account
for about 6 million ha (8%) of the total maize area in
the Third World.
During the period 1961-65 to 1983-85, world maize
production increased by 182 million t (CIMMYT 1987).
This is a 4.0% annual growth rate and represents a 84%
increase in world supplies. Most of this growth was
achieved through yield improvements. In developing
countries-though there was considerable regional
variation-yields increased at a 2.8% annual rate, while
the overall area expanded by 1.2% per year. China
reported the most rapid growth in yields among major
producers, with a 4.8% per annum rate of gain in yield
per year. In sharp contrast, yields in sub-Saharan
Africa increased at only a 0.9% yearly rate. For the
developing countries as a whole, production is not
increasing as fast as demand, and imports are rising
(Vocke 1987).

Utilization
Maize is used in more ways than any other cereal:
as a human food, a feed grain, a fodder crop, and for
hundreds of industrial purposes. Its grain, stalk, leaves,
cobs, tassel, and silks all have commercial value in most
settings, though that of the grain is the greatest. The
most diversified use of maize occurs in the United
States, where over 1,000 products in a typical super-
market contain maize in some form or another in their
makeup.
Worldwide, about 66% of all maize is used for
feeding livestock, 25% for human consumption, and
9% for industrial purposes and as seed (CIMMYT
1984). In the developing world, however, roughly 50%
of all maize is consumed by humans as a direct food
source, 43% is for livestock feed, and the remainder is
used for industrial and seed purposes (CIMMYT 1984).
Although maize is important as a food crop in Mexico,



















1. BACKGROUND ON MAIZE


MAIZE IN THE WORLD
ECONOMY

Area and Production
Maize, with a global harvest in 1985 of 449 million
metric tons from 133 million ha, ranked second to
wheat (with hulled rice third) among the world's cereal
crops (FAO 1986). Some 70 countries produce maize
on 100,000 ha or more; 53 of these are developing
countries. Developed market economies account for
30% of the global maize area but provide 50% of total
production, due to average yields that are three times
higher than the world average. Developing countries
account for approximately 60% of the total world
maize area but produce only 40% of the global harvest.
During 1983-85, developing countries produced an
average of 169 million tons (t)1 of maize per year
(CIMMYT 1987). Four countries accounted for 67%
of the Third World's maize production: China (68
million t), Brazil (21 million t), Mexico (14 million t),
Argentina (10 million t).
In total, there are 80 million ha planted with maize
in developing countries. Lowland tropical environments
account for 32 million ha or about 40% of the total area
planted with maize in the developing world. These
tropical maize growing environments are found in the
lowlands of eastern and western Africa, south of the
Sahara; the plains and delta areas of South Asia;
Southeast Asia; Central America and parts of Mexico;
and the lowland areas in Andean countries of South
America and Brazil. Temperate environments (e.g.,
Argentina, Chile, China, Middle East), accounting for
24 million ha (30%) of the total maize area, are in
developing countries. Subtropical and intermediate-
elevation zones (South Asia, Middle East, North Africa,
Mexico, Brazil, East Africa) account for approximately
18 million ha (22%) of the developing country maize

1All ton measurements are for metric tons.


area. Highland zones above 1,500 m (subtrop-
ical-temperate) in Mexico, Central America, Andean
countries, East Africa, and Himalayan countries account
for about 6 million ha (8%) of the total maize area in
the Third World.
During the period 1961-65 to 1983-85, world maize
production increased by 182 million t (CIMMYT 1987).
This is a 4.0% annual growth rate and represents a 84%
increase in world supplies. Most of this growth was
achieved through yield improvements. In developing
countries-though there was considerable regional
variation-yields increased at a 2.8% annual rate, while
the overall area expanded by 1.2% per year. China
reported the most rapid growth in yields among major
producers, with a 4.8% per annum rate of gain in yield
per year. In sharp contrast, yields in sub-Saharan
Africa increased at only a 0.9% yearly rate. For the
developing countries as a whole, production is not
increasing as fast as demand, and imports are rising
(Vocke 1987).

Utilization
Maize is used in more ways than any other cereal:
as a human food, a feed grain, a fodder crop, and for
hundreds of industrial purposes. Its grain, stalk, leaves,
cobs, tassel, and silks all have commercial value in most
settings, though that of the grain is the greatest. The
most diversified use of maize occurs in the United
States, where over 1,000 products in a typical super-
market contain maize in some form or another in their
makeup.
Worldwide, about 66% of all maize is used for
feeding livestock, 25% for human consumption, and
9% for industrial purposes and as seed (CIMMYT
1984). In the developing world, however, roughly 50%
of all maize is consumed by humans as a direct food
source, 43% is for livestock feed, and the remainder is
used for industrial and seed purposes (CIMMYT 1984).
Although maize is important as a food crop in Mexico,



















1. BACKGROUND ON MAIZE


MAIZE IN THE WORLD
ECONOMY

Area and Production
Maize, with a global harvest in 1985 of 449 million
metric tons from 133 million ha, ranked second to
wheat (with hulled rice third) among the world's cereal
crops (FAO 1986). Some 70 countries produce maize
on 100,000 ha or more; 53 of these are developing
countries. Developed market economies account for
30% of the global maize area but provide 50% of total
production, due to average yields that are three times
higher than the world average. Developing countries
account for approximately 60% of the total world
maize area but produce only 40% of the global harvest.
During 1983-85, developing countries produced an
average of 169 million tons (t)1 of maize per year
(CIMMYT 1987). Four countries accounted for 67%
of the Third World's maize production: China (68
million t), Brazil (21 million t), Mexico (14 million t),
Argentina (10 million t).
In total, there are 80 million ha planted with maize
in developing countries. Lowland tropical environments
account for 32 million ha or about 40% of the total area
planted with maize in the developing world. These
tropical maize growing environments are found in the
lowlands of eastern and western Africa, south of the
Sahara; the plains and delta areas of South Asia;
Southeast Asia; Central America and parts of Mexico;
and the lowland areas in Andean countries of South
America and Brazil. Temperate environments (e.g.,
Argentina, Chile, China, Middle East), accounting for
24 million ha (30%) of the total maize area, are in
developing countries. Subtropical and intermediate-
elevation zones (South Asia, Middle East, North Africa,
Mexico, Brazil, East Africa) account for approximately
18 million ha (22%) of the developing country maize

1All ton measurements are for metric tons.


area. Highland zones above 1,500 m (subtrop-
ical-temperate) in Mexico, Central America, Andean
countries, East Africa, and Himalayan countries account
for about 6 million ha (8%) of the total maize area in
the Third World.
During the period 1961-65 to 1983-85, world maize
production increased by 182 million t (CIMMYT 1987).
This is a 4.0% annual growth rate and represents a 84%
increase in world supplies. Most of this growth was
achieved through yield improvements. In developing
countries-though there was considerable regional
variation-yields increased at a 2.8% annual rate, while
the overall area expanded by 1.2% per year. China
reported the most rapid growth in yields among major
producers, with a 4.8% per annum rate of gain in yield
per year. In sharp contrast, yields in sub-Saharan
Africa increased at only a 0.9% yearly rate. For the
developing countries as a whole, production is not
increasing as fast as demand, and imports are rising
(Vocke 1987).

Utilization
Maize is used in more ways than any other cereal:
as a human food, a feed grain, a fodder crop, and for
hundreds of industrial purposes. Its grain, stalk, leaves,
cobs, tassel, and silks all have commercial value in most
settings, though that of the grain is the greatest. The
most diversified use of maize occurs in the United
States, where over 1,000 products in a typical super-
market contain maize in some form or another in their
makeup.
Worldwide, about 66% of all maize is used for
feeding livestock, 25% for human consumption, and
9% for industrial purposes and as seed (CIMMYT
1984). In the developing world, however, roughly 50%
of all maize is consumed by humans as a direct food
source, 43% is for livestock feed, and the remainder is
used for industrial and seed purposes (CIMMYT 1984).
Although maize is important as a food crop in Mexico,









IMPROVED MAIZE VARIETIES AND HYBRIDS


-tdL~ -~i;~ T


Figure 1. Cultivating maize interplanted with other crops in Honduras. Source: CIMMYT.


Ilt~L~I~L;EI


-- -A









BACKGROUND ON MAIZE


CentralAmerica and the Caribbean, the Andean coun-
tries of South America, and sub-Saharan Africa, it is
increasingly important as a feed grain in the newly
industrialized countries of the Pacific Rim, the
middle-income countries of Latin America, and the
major oil-exporting countries.

SOME BASIC BIOLOGICAL
CHARACTERISTICS OF MAIZE


Botanical Classification
Maize, Zea mays L. spp. mays, is a diploid (2n= 20)
member of the tribe Maydeae, Tripaceae, orAndropo-
neae (depending upon one's taxonomy), subfamily
Panicoideae of the Gramineae. Its native distribution
was restricted to the New World. Although the origins
of maize remain elusive, it is well established that at
least one kind of maize originated in the Valley of
Mexico (Galinat 1971, 1977; Mangelsdorf et al. 1964,
1967; Mangelsdorf 1974). The archeobotanical evi-
dence indicates that for several thousand years the
pencil thin cobs of this primitive plant nourished its
cultivators. Subsequently, new characteristics were added
to this primitive cultivar, presumably from the related
wild grass teosinte, and the domesticated genotypes
began to assume the proportions and characteristics of
present day maize land races. While reasonably close,
the affinity of maize with Tnipsacum L. is much less
than with the teosinte. However, there is little doubt
that maize, teosinte, and Trisacum share differing
kinds and amounts of common genetic information.

Climatic Adaptation
Maize is grown in more diverse areas of the world
than any other major crop. It is grown from sea level to
3,800 m elevation near Lake Titicaca in Bolivia and
Peru, from desert oases to zones having 11,000 mm
rainfall (Patifio 1956) along the western coast of Co-
lombia, and from about 42 latitude S near Chiloe
Island to about 50* latitude N on the Gaspe Peninsula
of New Brunswick, Canada. It is cultivated from north-
ern Europe and Russia to South Africa, eastward
through Asia, the Himalayas, China, Southeast Asia,
and the Pacific Islands. The genetic differences are vast
among the kinds of maize grown among the distinct
locales of these disparate areas. The diverse but par-
ticular conditions of soil, temperature, rainfall, relative
humidity, photoperiod, and light intensity have all


imposed selection pressures on the kinds of maize at
each site.

INFLUENCES ON MAIZE
IMPROVEMENT

In the industrialized societies, maize is bred for
mechanized agricultural technologies, highly engineered
milling and processing plants, sophisticated marketing
strategies, and various consumer tastes and choices.
These industrial endeavors are supported by, and are
part of, a well-functioning and highly developed infra-
structure. However, in those areas in which sufficient
levels of development do not exist, the farmer has
played an important role in the evolution of the kinds
of maize being grown. This is particularly so when
maize is used for direct human consumption rather
than as animal feed or industrial use.

Selection Criteria and Plant Structure
The structure of maize lends itself to stringent and
repeated scrutiny of each individual plant by its cultiva-
tors. Thus, selection of a desired type may be of
exceedingly high intensity. This kind of selection is
facilitated by the large physical structure of the plant;
all the above-ground parts are easily observed for
length, width, thickness, color, pubescence, position,
and numbers of plant parts and their shapes, angularity
or idealized architecture, husk cover, shank character-
istics, maturation rates, and reaction to insects, dis-
eases, or other stresses and perturbations.
The ear is particularly susceptible to selection cri-
teria. Each ear is harvested by hand and through
repeated handling in the husking, drying, storing and
shelling process, human preference comes to bear for
grain type. These traits include grain size, shape, color,
starch texture, characters pertaining to appearance,
cleanliness, and desirability for ultimate use. The suc-
cesses of the efforts are evident from the extant vari-
ability among the thousands of indigenous strains of
maize found throughout the world.

Selection Criteria and Use
Superimposed upon the selection pressure of envi-
ronments or biological stresses, such as temperature or
insects, are the additional selection criteria pertinent to
the local uses of the grain or other plant parts. Maize
is used as a staple in many forms of comestibles:
fermented and nonfermented drink, porridges, tortil-
las and other baked products, cooking oil, dyes, animal









BACKGROUND ON MAIZE


CentralAmerica and the Caribbean, the Andean coun-
tries of South America, and sub-Saharan Africa, it is
increasingly important as a feed grain in the newly
industrialized countries of the Pacific Rim, the
middle-income countries of Latin America, and the
major oil-exporting countries.

SOME BASIC BIOLOGICAL
CHARACTERISTICS OF MAIZE


Botanical Classification
Maize, Zea mays L. spp. mays, is a diploid (2n= 20)
member of the tribe Maydeae, Tripaceae, orAndropo-
neae (depending upon one's taxonomy), subfamily
Panicoideae of the Gramineae. Its native distribution
was restricted to the New World. Although the origins
of maize remain elusive, it is well established that at
least one kind of maize originated in the Valley of
Mexico (Galinat 1971, 1977; Mangelsdorf et al. 1964,
1967; Mangelsdorf 1974). The archeobotanical evi-
dence indicates that for several thousand years the
pencil thin cobs of this primitive plant nourished its
cultivators. Subsequently, new characteristics were added
to this primitive cultivar, presumably from the related
wild grass teosinte, and the domesticated genotypes
began to assume the proportions and characteristics of
present day maize land races. While reasonably close,
the affinity of maize with Tnipsacum L. is much less
than with the teosinte. However, there is little doubt
that maize, teosinte, and Trisacum share differing
kinds and amounts of common genetic information.

Climatic Adaptation
Maize is grown in more diverse areas of the world
than any other major crop. It is grown from sea level to
3,800 m elevation near Lake Titicaca in Bolivia and
Peru, from desert oases to zones having 11,000 mm
rainfall (Patifio 1956) along the western coast of Co-
lombia, and from about 42 latitude S near Chiloe
Island to about 50* latitude N on the Gaspe Peninsula
of New Brunswick, Canada. It is cultivated from north-
ern Europe and Russia to South Africa, eastward
through Asia, the Himalayas, China, Southeast Asia,
and the Pacific Islands. The genetic differences are vast
among the kinds of maize grown among the distinct
locales of these disparate areas. The diverse but par-
ticular conditions of soil, temperature, rainfall, relative
humidity, photoperiod, and light intensity have all


imposed selection pressures on the kinds of maize at
each site.

INFLUENCES ON MAIZE
IMPROVEMENT

In the industrialized societies, maize is bred for
mechanized agricultural technologies, highly engineered
milling and processing plants, sophisticated marketing
strategies, and various consumer tastes and choices.
These industrial endeavors are supported by, and are
part of, a well-functioning and highly developed infra-
structure. However, in those areas in which sufficient
levels of development do not exist, the farmer has
played an important role in the evolution of the kinds
of maize being grown. This is particularly so when
maize is used for direct human consumption rather
than as animal feed or industrial use.

Selection Criteria and Plant Structure
The structure of maize lends itself to stringent and
repeated scrutiny of each individual plant by its cultiva-
tors. Thus, selection of a desired type may be of
exceedingly high intensity. This kind of selection is
facilitated by the large physical structure of the plant;
all the above-ground parts are easily observed for
length, width, thickness, color, pubescence, position,
and numbers of plant parts and their shapes, angularity
or idealized architecture, husk cover, shank character-
istics, maturation rates, and reaction to insects, dis-
eases, or other stresses and perturbations.
The ear is particularly susceptible to selection cri-
teria. Each ear is harvested by hand and through
repeated handling in the husking, drying, storing and
shelling process, human preference comes to bear for
grain type. These traits include grain size, shape, color,
starch texture, characters pertaining to appearance,
cleanliness, and desirability for ultimate use. The suc-
cesses of the efforts are evident from the extant vari-
ability among the thousands of indigenous strains of
maize found throughout the world.

Selection Criteria and Use
Superimposed upon the selection pressure of envi-
ronments or biological stresses, such as temperature or
insects, are the additional selection criteria pertinent to
the local uses of the grain or other plant parts. Maize
is used as a staple in many forms of comestibles:
fermented and nonfermented drink, porridges, tortil-
las and other baked products, cooking oil, dyes, animal









BACKGROUND ON MAIZE


CentralAmerica and the Caribbean, the Andean coun-
tries of South America, and sub-Saharan Africa, it is
increasingly important as a feed grain in the newly
industrialized countries of the Pacific Rim, the
middle-income countries of Latin America, and the
major oil-exporting countries.

SOME BASIC BIOLOGICAL
CHARACTERISTICS OF MAIZE


Botanical Classification
Maize, Zea mays L. spp. mays, is a diploid (2n= 20)
member of the tribe Maydeae, Tripaceae, orAndropo-
neae (depending upon one's taxonomy), subfamily
Panicoideae of the Gramineae. Its native distribution
was restricted to the New World. Although the origins
of maize remain elusive, it is well established that at
least one kind of maize originated in the Valley of
Mexico (Galinat 1971, 1977; Mangelsdorf et al. 1964,
1967; Mangelsdorf 1974). The archeobotanical evi-
dence indicates that for several thousand years the
pencil thin cobs of this primitive plant nourished its
cultivators. Subsequently, new characteristics were added
to this primitive cultivar, presumably from the related
wild grass teosinte, and the domesticated genotypes
began to assume the proportions and characteristics of
present day maize land races. While reasonably close,
the affinity of maize with Tnipsacum L. is much less
than with the teosinte. However, there is little doubt
that maize, teosinte, and Trisacum share differing
kinds and amounts of common genetic information.

Climatic Adaptation
Maize is grown in more diverse areas of the world
than any other major crop. It is grown from sea level to
3,800 m elevation near Lake Titicaca in Bolivia and
Peru, from desert oases to zones having 11,000 mm
rainfall (Patifio 1956) along the western coast of Co-
lombia, and from about 42 latitude S near Chiloe
Island to about 50* latitude N on the Gaspe Peninsula
of New Brunswick, Canada. It is cultivated from north-
ern Europe and Russia to South Africa, eastward
through Asia, the Himalayas, China, Southeast Asia,
and the Pacific Islands. The genetic differences are vast
among the kinds of maize grown among the distinct
locales of these disparate areas. The diverse but par-
ticular conditions of soil, temperature, rainfall, relative
humidity, photoperiod, and light intensity have all


imposed selection pressures on the kinds of maize at
each site.

INFLUENCES ON MAIZE
IMPROVEMENT

In the industrialized societies, maize is bred for
mechanized agricultural technologies, highly engineered
milling and processing plants, sophisticated marketing
strategies, and various consumer tastes and choices.
These industrial endeavors are supported by, and are
part of, a well-functioning and highly developed infra-
structure. However, in those areas in which sufficient
levels of development do not exist, the farmer has
played an important role in the evolution of the kinds
of maize being grown. This is particularly so when
maize is used for direct human consumption rather
than as animal feed or industrial use.

Selection Criteria and Plant Structure
The structure of maize lends itself to stringent and
repeated scrutiny of each individual plant by its cultiva-
tors. Thus, selection of a desired type may be of
exceedingly high intensity. This kind of selection is
facilitated by the large physical structure of the plant;
all the above-ground parts are easily observed for
length, width, thickness, color, pubescence, position,
and numbers of plant parts and their shapes, angularity
or idealized architecture, husk cover, shank character-
istics, maturation rates, and reaction to insects, dis-
eases, or other stresses and perturbations.
The ear is particularly susceptible to selection cri-
teria. Each ear is harvested by hand and through
repeated handling in the husking, drying, storing and
shelling process, human preference comes to bear for
grain type. These traits include grain size, shape, color,
starch texture, characters pertaining to appearance,
cleanliness, and desirability for ultimate use. The suc-
cesses of the efforts are evident from the extant vari-
ability among the thousands of indigenous strains of
maize found throughout the world.

Selection Criteria and Use
Superimposed upon the selection pressure of envi-
ronments or biological stresses, such as temperature or
insects, are the additional selection criteria pertinent to
the local uses of the grain or other plant parts. Maize
is used as a staple in many forms of comestibles:
fermented and nonfermented drink, porridges, tortil-
las and other baked products, cooking oil, dyes, animal









BACKGROUND ON MAIZE


CentralAmerica and the Caribbean, the Andean coun-
tries of South America, and sub-Saharan Africa, it is
increasingly important as a feed grain in the newly
industrialized countries of the Pacific Rim, the
middle-income countries of Latin America, and the
major oil-exporting countries.

SOME BASIC BIOLOGICAL
CHARACTERISTICS OF MAIZE


Botanical Classification
Maize, Zea mays L. spp. mays, is a diploid (2n= 20)
member of the tribe Maydeae, Tripaceae, orAndropo-
neae (depending upon one's taxonomy), subfamily
Panicoideae of the Gramineae. Its native distribution
was restricted to the New World. Although the origins
of maize remain elusive, it is well established that at
least one kind of maize originated in the Valley of
Mexico (Galinat 1971, 1977; Mangelsdorf et al. 1964,
1967; Mangelsdorf 1974). The archeobotanical evi-
dence indicates that for several thousand years the
pencil thin cobs of this primitive plant nourished its
cultivators. Subsequently, new characteristics were added
to this primitive cultivar, presumably from the related
wild grass teosinte, and the domesticated genotypes
began to assume the proportions and characteristics of
present day maize land races. While reasonably close,
the affinity of maize with Tnipsacum L. is much less
than with the teosinte. However, there is little doubt
that maize, teosinte, and Trisacum share differing
kinds and amounts of common genetic information.

Climatic Adaptation
Maize is grown in more diverse areas of the world
than any other major crop. It is grown from sea level to
3,800 m elevation near Lake Titicaca in Bolivia and
Peru, from desert oases to zones having 11,000 mm
rainfall (Patifio 1956) along the western coast of Co-
lombia, and from about 42 latitude S near Chiloe
Island to about 50* latitude N on the Gaspe Peninsula
of New Brunswick, Canada. It is cultivated from north-
ern Europe and Russia to South Africa, eastward
through Asia, the Himalayas, China, Southeast Asia,
and the Pacific Islands. The genetic differences are vast
among the kinds of maize grown among the distinct
locales of these disparate areas. The diverse but par-
ticular conditions of soil, temperature, rainfall, relative
humidity, photoperiod, and light intensity have all


imposed selection pressures on the kinds of maize at
each site.

INFLUENCES ON MAIZE
IMPROVEMENT

In the industrialized societies, maize is bred for
mechanized agricultural technologies, highly engineered
milling and processing plants, sophisticated marketing
strategies, and various consumer tastes and choices.
These industrial endeavors are supported by, and are
part of, a well-functioning and highly developed infra-
structure. However, in those areas in which sufficient
levels of development do not exist, the farmer has
played an important role in the evolution of the kinds
of maize being grown. This is particularly so when
maize is used for direct human consumption rather
than as animal feed or industrial use.

Selection Criteria and Plant Structure
The structure of maize lends itself to stringent and
repeated scrutiny of each individual plant by its cultiva-
tors. Thus, selection of a desired type may be of
exceedingly high intensity. This kind of selection is
facilitated by the large physical structure of the plant;
all the above-ground parts are easily observed for
length, width, thickness, color, pubescence, position,
and numbers of plant parts and their shapes, angularity
or idealized architecture, husk cover, shank character-
istics, maturation rates, and reaction to insects, dis-
eases, or other stresses and perturbations.
The ear is particularly susceptible to selection cri-
teria. Each ear is harvested by hand and through
repeated handling in the husking, drying, storing and
shelling process, human preference comes to bear for
grain type. These traits include grain size, shape, color,
starch texture, characters pertaining to appearance,
cleanliness, and desirability for ultimate use. The suc-
cesses of the efforts are evident from the extant vari-
ability among the thousands of indigenous strains of
maize found throughout the world.

Selection Criteria and Use
Superimposed upon the selection pressure of envi-
ronments or biological stresses, such as temperature or
insects, are the additional selection criteria pertinent to
the local uses of the grain or other plant parts. Maize
is used as a staple in many forms of comestibles:
fermented and nonfermented drink, porridges, tortil-
las and other baked products, cooking oil, dyes, animal









BACKGROUND ON MAIZE


CentralAmerica and the Caribbean, the Andean coun-
tries of South America, and sub-Saharan Africa, it is
increasingly important as a feed grain in the newly
industrialized countries of the Pacific Rim, the
middle-income countries of Latin America, and the
major oil-exporting countries.

SOME BASIC BIOLOGICAL
CHARACTERISTICS OF MAIZE


Botanical Classification
Maize, Zea mays L. spp. mays, is a diploid (2n= 20)
member of the tribe Maydeae, Tripaceae, orAndropo-
neae (depending upon one's taxonomy), subfamily
Panicoideae of the Gramineae. Its native distribution
was restricted to the New World. Although the origins
of maize remain elusive, it is well established that at
least one kind of maize originated in the Valley of
Mexico (Galinat 1971, 1977; Mangelsdorf et al. 1964,
1967; Mangelsdorf 1974). The archeobotanical evi-
dence indicates that for several thousand years the
pencil thin cobs of this primitive plant nourished its
cultivators. Subsequently, new characteristics were added
to this primitive cultivar, presumably from the related
wild grass teosinte, and the domesticated genotypes
began to assume the proportions and characteristics of
present day maize land races. While reasonably close,
the affinity of maize with Tnipsacum L. is much less
than with the teosinte. However, there is little doubt
that maize, teosinte, and Trisacum share differing
kinds and amounts of common genetic information.

Climatic Adaptation
Maize is grown in more diverse areas of the world
than any other major crop. It is grown from sea level to
3,800 m elevation near Lake Titicaca in Bolivia and
Peru, from desert oases to zones having 11,000 mm
rainfall (Patifio 1956) along the western coast of Co-
lombia, and from about 42 latitude S near Chiloe
Island to about 50* latitude N on the Gaspe Peninsula
of New Brunswick, Canada. It is cultivated from north-
ern Europe and Russia to South Africa, eastward
through Asia, the Himalayas, China, Southeast Asia,
and the Pacific Islands. The genetic differences are vast
among the kinds of maize grown among the distinct
locales of these disparate areas. The diverse but par-
ticular conditions of soil, temperature, rainfall, relative
humidity, photoperiod, and light intensity have all


imposed selection pressures on the kinds of maize at
each site.

INFLUENCES ON MAIZE
IMPROVEMENT

In the industrialized societies, maize is bred for
mechanized agricultural technologies, highly engineered
milling and processing plants, sophisticated marketing
strategies, and various consumer tastes and choices.
These industrial endeavors are supported by, and are
part of, a well-functioning and highly developed infra-
structure. However, in those areas in which sufficient
levels of development do not exist, the farmer has
played an important role in the evolution of the kinds
of maize being grown. This is particularly so when
maize is used for direct human consumption rather
than as animal feed or industrial use.

Selection Criteria and Plant Structure
The structure of maize lends itself to stringent and
repeated scrutiny of each individual plant by its cultiva-
tors. Thus, selection of a desired type may be of
exceedingly high intensity. This kind of selection is
facilitated by the large physical structure of the plant;
all the above-ground parts are easily observed for
length, width, thickness, color, pubescence, position,
and numbers of plant parts and their shapes, angularity
or idealized architecture, husk cover, shank character-
istics, maturation rates, and reaction to insects, dis-
eases, or other stresses and perturbations.
The ear is particularly susceptible to selection cri-
teria. Each ear is harvested by hand and through
repeated handling in the husking, drying, storing and
shelling process, human preference comes to bear for
grain type. These traits include grain size, shape, color,
starch texture, characters pertaining to appearance,
cleanliness, and desirability for ultimate use. The suc-
cesses of the efforts are evident from the extant vari-
ability among the thousands of indigenous strains of
maize found throughout the world.

Selection Criteria and Use
Superimposed upon the selection pressure of envi-
ronments or biological stresses, such as temperature or
insects, are the additional selection criteria pertinent to
the local uses of the grain or other plant parts. Maize
is used as a staple in many forms of comestibles:
fermented and nonfermented drink, porridges, tortil-
las and other baked products, cooking oil, dyes, animal









BACKGROUND ON MAIZE


CentralAmerica and the Caribbean, the Andean coun-
tries of South America, and sub-Saharan Africa, it is
increasingly important as a feed grain in the newly
industrialized countries of the Pacific Rim, the
middle-income countries of Latin America, and the
major oil-exporting countries.

SOME BASIC BIOLOGICAL
CHARACTERISTICS OF MAIZE


Botanical Classification
Maize, Zea mays L. spp. mays, is a diploid (2n= 20)
member of the tribe Maydeae, Tripaceae, orAndropo-
neae (depending upon one's taxonomy), subfamily
Panicoideae of the Gramineae. Its native distribution
was restricted to the New World. Although the origins
of maize remain elusive, it is well established that at
least one kind of maize originated in the Valley of
Mexico (Galinat 1971, 1977; Mangelsdorf et al. 1964,
1967; Mangelsdorf 1974). The archeobotanical evi-
dence indicates that for several thousand years the
pencil thin cobs of this primitive plant nourished its
cultivators. Subsequently, new characteristics were added
to this primitive cultivar, presumably from the related
wild grass teosinte, and the domesticated genotypes
began to assume the proportions and characteristics of
present day maize land races. While reasonably close,
the affinity of maize with Tnipsacum L. is much less
than with the teosinte. However, there is little doubt
that maize, teosinte, and Trisacum share differing
kinds and amounts of common genetic information.

Climatic Adaptation
Maize is grown in more diverse areas of the world
than any other major crop. It is grown from sea level to
3,800 m elevation near Lake Titicaca in Bolivia and
Peru, from desert oases to zones having 11,000 mm
rainfall (Patifio 1956) along the western coast of Co-
lombia, and from about 42 latitude S near Chiloe
Island to about 50* latitude N on the Gaspe Peninsula
of New Brunswick, Canada. It is cultivated from north-
ern Europe and Russia to South Africa, eastward
through Asia, the Himalayas, China, Southeast Asia,
and the Pacific Islands. The genetic differences are vast
among the kinds of maize grown among the distinct
locales of these disparate areas. The diverse but par-
ticular conditions of soil, temperature, rainfall, relative
humidity, photoperiod, and light intensity have all


imposed selection pressures on the kinds of maize at
each site.

INFLUENCES ON MAIZE
IMPROVEMENT

In the industrialized societies, maize is bred for
mechanized agricultural technologies, highly engineered
milling and processing plants, sophisticated marketing
strategies, and various consumer tastes and choices.
These industrial endeavors are supported by, and are
part of, a well-functioning and highly developed infra-
structure. However, in those areas in which sufficient
levels of development do not exist, the farmer has
played an important role in the evolution of the kinds
of maize being grown. This is particularly so when
maize is used for direct human consumption rather
than as animal feed or industrial use.

Selection Criteria and Plant Structure
The structure of maize lends itself to stringent and
repeated scrutiny of each individual plant by its cultiva-
tors. Thus, selection of a desired type may be of
exceedingly high intensity. This kind of selection is
facilitated by the large physical structure of the plant;
all the above-ground parts are easily observed for
length, width, thickness, color, pubescence, position,
and numbers of plant parts and their shapes, angularity
or idealized architecture, husk cover, shank character-
istics, maturation rates, and reaction to insects, dis-
eases, or other stresses and perturbations.
The ear is particularly susceptible to selection cri-
teria. Each ear is harvested by hand and through
repeated handling in the husking, drying, storing and
shelling process, human preference comes to bear for
grain type. These traits include grain size, shape, color,
starch texture, characters pertaining to appearance,
cleanliness, and desirability for ultimate use. The suc-
cesses of the efforts are evident from the extant vari-
ability among the thousands of indigenous strains of
maize found throughout the world.

Selection Criteria and Use
Superimposed upon the selection pressure of envi-
ronments or biological stresses, such as temperature or
insects, are the additional selection criteria pertinent to
the local uses of the grain or other plant parts. Maize
is used as a staple in many forms of comestibles:
fermented and nonfermented drink, porridges, tortil-
las and other baked products, cooking oil, dyes, animal









IMPROVED MAIZE VARIETIES AND HYBRIDS


Figure 2. Preparing tortillas from maize in a Latin American home. Source: CIMMYT.


and poultry feedstuffs, fodders, medicinals, ceremo-
nial and religious essentials, physical support of a
companion crop in multicropping systems, toys, dolls,
effigies and other household or community symbol-
isms, and rawmaterialfor a host of industrial products.

Selection Criteria and
Population Structure
Maize is a highly evolved cross-fertilizing annual.
Generally, each plant is an indigenous or intermating
entity that is unique by virtue of its hybrid nature,
having originated from a male gamete of one plant and
a female gamete from another. While the plants in such
a population may be phenotypically homogeneous as a
consequence of selection, the individual genetic condi-
tion of each plant is essentially heterozygous. How-
ever, when two completely homozygous inbred lines
are used to form an F1 hybrid, all the progeny in that
first generation will be genetically identical. Subse-
quent generations will revert to individually distinct
heterozygous plants comprising all the possible combi-
nations of the alleles of genes from the inbred lines.
This is distinct from what occurs in self-pollinating
species, such as wheat or rice, in which a population is
largely homozygous: each plant is identical to another.
In some self-pollinations, an outcross-an F1 hy-


brid-occurs and the approach to homozygosity of the
progeny from any heterogenous individual (the F1)
increases by one-half in each successive generation.
However, the population will then contain a mixture of
distinct homozygous lines and a decreasing number of
heterozygous individuals.
The monoecious character of maize (separate male
and female inflorescences on the same plant) facili-
tates controlled pollination. Thus, many of the breed-
ing methods used for self-pollinating species are used
with maize for certain qualitative traits and conditions,
such as simply inherited reactions to diseases. Quanti-
tative characters (yield) and the kinds of dominant,
additive, or interactive gene action controlling such
traits and hybrid vigor have led to the development of
numerous breeding methodologies. These have been
used to develop inbred lines for hybrids, synthetics,
composites, or improved varieties, and for population
improvement as source materials. (See appendix A for
a brief definition of hybrids, synthetics, and compos-
ites.)

Infrastructure and Plant Breeding
Sustained production of high-yielding hybrids
requires an adequate technological and agricultural
infrastructure comprised of credit, transportation, proc-









IMPROVED MAIZE VARIETIES AND HYBRIDS


Figure 2. Preparing tortillas from maize in a Latin American home. Source: CIMMYT.


and poultry feedstuffs, fodders, medicinals, ceremo-
nial and religious essentials, physical support of a
companion crop in multicropping systems, toys, dolls,
effigies and other household or community symbol-
isms, and rawmaterialfor a host of industrial products.

Selection Criteria and
Population Structure
Maize is a highly evolved cross-fertilizing annual.
Generally, each plant is an indigenous or intermating
entity that is unique by virtue of its hybrid nature,
having originated from a male gamete of one plant and
a female gamete from another. While the plants in such
a population may be phenotypically homogeneous as a
consequence of selection, the individual genetic condi-
tion of each plant is essentially heterozygous. How-
ever, when two completely homozygous inbred lines
are used to form an F1 hybrid, all the progeny in that
first generation will be genetically identical. Subse-
quent generations will revert to individually distinct
heterozygous plants comprising all the possible combi-
nations of the alleles of genes from the inbred lines.
This is distinct from what occurs in self-pollinating
species, such as wheat or rice, in which a population is
largely homozygous: each plant is identical to another.
In some self-pollinations, an outcross-an F1 hy-


brid-occurs and the approach to homozygosity of the
progeny from any heterogenous individual (the F1)
increases by one-half in each successive generation.
However, the population will then contain a mixture of
distinct homozygous lines and a decreasing number of
heterozygous individuals.
The monoecious character of maize (separate male
and female inflorescences on the same plant) facili-
tates controlled pollination. Thus, many of the breed-
ing methods used for self-pollinating species are used
with maize for certain qualitative traits and conditions,
such as simply inherited reactions to diseases. Quanti-
tative characters (yield) and the kinds of dominant,
additive, or interactive gene action controlling such
traits and hybrid vigor have led to the development of
numerous breeding methodologies. These have been
used to develop inbred lines for hybrids, synthetics,
composites, or improved varieties, and for population
improvement as source materials. (See appendix A for
a brief definition of hybrids, synthetics, and compos-
ites.)

Infrastructure and Plant Breeding
Sustained production of high-yielding hybrids
requires an adequate technological and agricultural
infrastructure comprised of credit, transportation, proc-









BACKGROUND ON MAIZE


essing, marketing, educational, and other agricultural
support systems. Areas lacking these facets are either
unsuitable or less developed for hybrid production. In
these latter cases, maize is usually produced from
indigenous races, improved varieties, synthetics, or
from varietal crosses. Indeed, most national programs
in the developing world produce improved maize
genotypes via these latter systems rather than by the
use of single, three-way, or double-cross hybrids.
Commercial breeding efforts are sustained only in
the more advanced maize growing areas, as investment
returns are made only by repeated seed sales of hybrid
seed. Where farmers save or sell seed from a hybrid for
replanting, yield potential decreases appreciably, and
agronomically undesirable recombinant characteris-
tics are expressed in the next segregating generation.
Neither the farmer nor the marketplace will tolerate
this. Thus, maize improvement programs in less ad-
vanced areas are based on improved varieties, modi-


fied hybrids, synthetics, or varietal crosses. These are
usually produced by governmental or international
agencies mandated by agricultural development needs
rather than the requirement to make a profit. These
latter agencies also develop single crosses or other
hybrids for commercial production, but when seed
sales volume reaches an appropriate level, commercial
companies soon appear and target hybrid seed sales on
more specific areas of their product's adaptability than
is normally done by a development agency.
The presence (or absence) of effective seed pro-
duction organizations is the major determinant of the
type of maize varieties used by farmers around the
world. Where adequately developed seed industries
exist, F1 hybrids are generally the "standard." Where
seed industries are less well-developed and/or where
farmers grow maize as a subsistence crop for home
consumption, open-pollinated varieties, often unim-
proved, are the dominant types.



















2. INTERNATIONAL GERMPLASM

DEVELOPMENT PROGRAMS

AND NETWORKS


EARLY MAIZE GERMPLASM
EFFORTS AND APPROACHES
The rapid spread of hybrid maize production in the
United States during the 1940s was accompanied by
the disappearance of indigenous maize varieties. The
loss of those genetic resources, products of hundreds
or thousands of years of evolution under domestica-
tion, could restrict future maize improvement and
deprive us of genes of great potential importance.
There was a growing realization that the genetic diver-
sity among native strains and varieties in Latin Amer-
ica and the Caribbean would also become extinct with
increased planting of improved varieties and hybrids
that had begun in those areas. Concern for this situ-
ation led to concerted efforts beginning in the 1940s
and 1950s to collect, preserve, and classify native maize
varieties and strains in Latin America. These early
efforts in maize germplasm collection and classifica-
tion led to the identification and development of some
outstanding germplasm complexes in the Americas,
which later also proved to be very valuable to the maize
breeding programs in Asia and Africa.

Germplasm Collections in
Latin America
The Cooperative Maize Improvement Program of
the Mexican Ministry of Agriculture and the Rockefeller
Foundation, initiated in 1943, immediately began col-
lecting the native maize varieties and strains through-
out Mexico to serve as a germplasm base for improve-
ment. The myriad kinds of variability in this hodge-
podge of diversity was reduced by several criteria into
small groups containing similar or like kinds of recog-
nizable traits. These smaller groups were defined and
characterized as races (Wellhausen et al. 1952). Simi-


lar procedures were subsequently used in other areas
to describe on a preliminary basis the races of maize in
the NewWorld (Brieger et al. 1958; Brown 1960; Grant
et al. 1963; Grobman et al. 1961; Hatheway 1957;
Ramirez et al. 1960; Roberts et al. 1957; Stakman et al.
1967; Timothy et al. 1961, 1963; Wellhausen et al.
1957).
Over 280 races were described, with some overlap,
but for the first time the variation in an important world
crop was classified into easily recognized and workable
groups. Additional races in both the New and Old
Worlds have been described subsequently, but these
studies are generally of restricted geographical scope.
(See Brown and Goodman 1977; Goodman 1978;
Hallauer and Miranda Fo 1981.)
The similarity of many of the races and their evolu-
tionary histories have led to additional subsequent
groupings of races into groups or racial complexes,
mostlyby Goodman andhis coworkers. (See Goodman
1978 and Brown and Goodman 1977.) The identifica-
tion of these complexes, coupled with the results and
experience from plant breeding studies, has begun to
enable the identification of superior kinds of germplasm
for rapid improvement of yield and other characteris-
tics.
The vast array of diversity in this material, the
specific requirements for adaptation to local environ-
ments, demands by local markets, and preferences
dictated by human consumption added impetus to the
need for collections. The obvious similarity of certain
types of maize in the Caribbean Basin to those of the
eastern coast of Mexico, and of maize in northern and
western South America to either western Mexico or
southern Mexico and highland Central America, indi-
cated that collections outside Mexico would also be



















2. INTERNATIONAL GERMPLASM

DEVELOPMENT PROGRAMS

AND NETWORKS


EARLY MAIZE GERMPLASM
EFFORTS AND APPROACHES
The rapid spread of hybrid maize production in the
United States during the 1940s was accompanied by
the disappearance of indigenous maize varieties. The
loss of those genetic resources, products of hundreds
or thousands of years of evolution under domestica-
tion, could restrict future maize improvement and
deprive us of genes of great potential importance.
There was a growing realization that the genetic diver-
sity among native strains and varieties in Latin Amer-
ica and the Caribbean would also become extinct with
increased planting of improved varieties and hybrids
that had begun in those areas. Concern for this situ-
ation led to concerted efforts beginning in the 1940s
and 1950s to collect, preserve, and classify native maize
varieties and strains in Latin America. These early
efforts in maize germplasm collection and classifica-
tion led to the identification and development of some
outstanding germplasm complexes in the Americas,
which later also proved to be very valuable to the maize
breeding programs in Asia and Africa.

Germplasm Collections in
Latin America
The Cooperative Maize Improvement Program of
the Mexican Ministry of Agriculture and the Rockefeller
Foundation, initiated in 1943, immediately began col-
lecting the native maize varieties and strains through-
out Mexico to serve as a germplasm base for improve-
ment. The myriad kinds of variability in this hodge-
podge of diversity was reduced by several criteria into
small groups containing similar or like kinds of recog-
nizable traits. These smaller groups were defined and
characterized as races (Wellhausen et al. 1952). Simi-


lar procedures were subsequently used in other areas
to describe on a preliminary basis the races of maize in
the NewWorld (Brieger et al. 1958; Brown 1960; Grant
et al. 1963; Grobman et al. 1961; Hatheway 1957;
Ramirez et al. 1960; Roberts et al. 1957; Stakman et al.
1967; Timothy et al. 1961, 1963; Wellhausen et al.
1957).
Over 280 races were described, with some overlap,
but for the first time the variation in an important world
crop was classified into easily recognized and workable
groups. Additional races in both the New and Old
Worlds have been described subsequently, but these
studies are generally of restricted geographical scope.
(See Brown and Goodman 1977; Goodman 1978;
Hallauer and Miranda Fo 1981.)
The similarity of many of the races and their evolu-
tionary histories have led to additional subsequent
groupings of races into groups or racial complexes,
mostlyby Goodman andhis coworkers. (See Goodman
1978 and Brown and Goodman 1977.) The identifica-
tion of these complexes, coupled with the results and
experience from plant breeding studies, has begun to
enable the identification of superior kinds of germplasm
for rapid improvement of yield and other characteris-
tics.
The vast array of diversity in this material, the
specific requirements for adaptation to local environ-
ments, demands by local markets, and preferences
dictated by human consumption added impetus to the
need for collections. The obvious similarity of certain
types of maize in the Caribbean Basin to those of the
eastern coast of Mexico, and of maize in northern and
western South America to either western Mexico or
southern Mexico and highland Central America, indi-
cated that collections outside Mexico would also be



















2. INTERNATIONAL GERMPLASM

DEVELOPMENT PROGRAMS

AND NETWORKS


EARLY MAIZE GERMPLASM
EFFORTS AND APPROACHES
The rapid spread of hybrid maize production in the
United States during the 1940s was accompanied by
the disappearance of indigenous maize varieties. The
loss of those genetic resources, products of hundreds
or thousands of years of evolution under domestica-
tion, could restrict future maize improvement and
deprive us of genes of great potential importance.
There was a growing realization that the genetic diver-
sity among native strains and varieties in Latin Amer-
ica and the Caribbean would also become extinct with
increased planting of improved varieties and hybrids
that had begun in those areas. Concern for this situ-
ation led to concerted efforts beginning in the 1940s
and 1950s to collect, preserve, and classify native maize
varieties and strains in Latin America. These early
efforts in maize germplasm collection and classifica-
tion led to the identification and development of some
outstanding germplasm complexes in the Americas,
which later also proved to be very valuable to the maize
breeding programs in Asia and Africa.

Germplasm Collections in
Latin America
The Cooperative Maize Improvement Program of
the Mexican Ministry of Agriculture and the Rockefeller
Foundation, initiated in 1943, immediately began col-
lecting the native maize varieties and strains through-
out Mexico to serve as a germplasm base for improve-
ment. The myriad kinds of variability in this hodge-
podge of diversity was reduced by several criteria into
small groups containing similar or like kinds of recog-
nizable traits. These smaller groups were defined and
characterized as races (Wellhausen et al. 1952). Simi-


lar procedures were subsequently used in other areas
to describe on a preliminary basis the races of maize in
the NewWorld (Brieger et al. 1958; Brown 1960; Grant
et al. 1963; Grobman et al. 1961; Hatheway 1957;
Ramirez et al. 1960; Roberts et al. 1957; Stakman et al.
1967; Timothy et al. 1961, 1963; Wellhausen et al.
1957).
Over 280 races were described, with some overlap,
but for the first time the variation in an important world
crop was classified into easily recognized and workable
groups. Additional races in both the New and Old
Worlds have been described subsequently, but these
studies are generally of restricted geographical scope.
(See Brown and Goodman 1977; Goodman 1978;
Hallauer and Miranda Fo 1981.)
The similarity of many of the races and their evolu-
tionary histories have led to additional subsequent
groupings of races into groups or racial complexes,
mostlyby Goodman andhis coworkers. (See Goodman
1978 and Brown and Goodman 1977.) The identifica-
tion of these complexes, coupled with the results and
experience from plant breeding studies, has begun to
enable the identification of superior kinds of germplasm
for rapid improvement of yield and other characteris-
tics.
The vast array of diversity in this material, the
specific requirements for adaptation to local environ-
ments, demands by local markets, and preferences
dictated by human consumption added impetus to the
need for collections. The obvious similarity of certain
types of maize in the Caribbean Basin to those of the
eastern coast of Mexico, and of maize in northern and
western South America to either western Mexico or
southern Mexico and highland Central America, indi-
cated that collections outside Mexico would also be









IMPROVED MAIZE VARIETIES AND HYBRIDS


Figure 3. Genetic diversity of maize is expressed in these highly varied ears. Source: CIMMYT.


essential. Similarly, the Cooperative Maize Improve-
ment Program of the Colombian Ministry of Agricul-
ture and the Rockefeller Foundation begun in 1950
reiterated the need to collect maize beyond the Colom-
bian border. Activities by commercial seed companies
and universities in the industrialized countries during
this time period also stressed the need for collection
(Brown 1960; Cutler 1946; Hatheway 1957).
The National Academy of Sciences-National Re-
search Council (U.S.) formed the Committee on Pres-
ervation of Indigenous Strains of Maize to sponsor a
project that would collect, preserve, and study for
future use as many land races and varieties of the
Americas as possible (Clark 1954; 1956). Additional
support and cooperation for this work was received
from the Rockefeller Foundation, numerous govern-
ments, and several universities. The collections were
made, studied, and described in a "Races of Maize"
bulletin series. These germplasm collections were to
be maintained and made available to qualified scien-
tists for additional study, research, and maize improve-


ment. The Central American and Caribbean collec-
tions were to be maintained and distributed at Chap-
ingo, Mexico; those from western and Andean South
America from Venezuela through Chile at Medellin,
Colombia; and those from eastern South America and
the Guianas at Piracicaba, Brazil. As a safeguard
against loss, duplicate samples of the collections were
to be sent through the USDA facilities at Glen Dale,
Maryland, and eventually put in long-term storage at
the National Seed Storage Laboratory at Fort Collins,
Colorado. However, the reality of those events has
been less than satisfactory (Goodman 1984; Timothy
and Goodman 1979).

Development of Improved Varieties
and Hybrids in Latin America
During the 1940s and 1950s, several national maize
improvement programs made appreciable impact in
the development and distribution of improved varieties
and hybrids. The Rockefeller Foundation initiated a
Central American Corn Improvement Project in 1954









INTERNATIONAL GERMPLASM DEVELOPMENT


(Stakman 1967). Particularly notable national maize
breeding programs were found in Mexico, Colombia,
Cuba, Venezuela, Brazil, and Argentina. Materials
from these programs made considerable contributions
to breeding stocks and are still being used.
An improved yellow flint variety, Venezuela-1, was
developed by several cycles of mass selection from two
Cuban varieties (Langham 1942). Although not stated,
this Coastal Tropical Flint has Cuban Flint Cateto in its
background. The development in Colombia of several
varieties, Colombia 1, Colombia 2, and ETO (Chavar-
riaga 1966), were of considerable worldwide impor-
tance. That germplasm is an important component of
many breeding programs of the world.
Colombia 1 and Colombia 2, yellow and white
varieties, respectively, were both developed from a
series of crosses among three sources followed by
selection for combining ability among sib-mating/
progenies. The three sources of germplasm were the
yellow flint, Venezuela 1; the white Colombian race
predominantly from the Cauca Valley, Blanco Comfin;
and a white local variety from near Urrao, Blanco de
Urrao. Blanco de Urrao apparently was made up
primarily of the Colombian races, Comfin and
Chococefo. Subsequently, Venezuela 1 and Colombia
1 were subjected to a host of controlled pollinations
from lines, hybrids, and varieties from Venezuela,
USA, Brazil, Mexico, Puerto Rico, Argentina, and
Cuba. Additional testing, selection, and hybridization
of this material led to the selection of 12 ears used to
form ETO, a yellow-flint synthetic variety (Chavar-
riaga 1966).
One consequence of the broad genetic background
of ETO was that it had segregating kernel colors. By
selling and test crossing onto a white tester, a large
number of pure white ETO lines were selected and
recombined to form ETO blanco. Another conse-
quence of the diversity within both ETO and ETO
blanco was that it was possible to develop double-cross
hybrids whose four lines derived entirely from within
one or the other variety. The yield potential of material
from these varieties was such that they are still impor-
tant components of many breeding programs.
In the early stages of the Mexican Govern-
ment-Rockefeller Foundation Program, it was appar-
ent that seed multiplication and distribution of the
better landraces might clearly give rapid and substan-
tial increases in maize production in the high plateau.
From 240 collections in the States of Guanajuato,
Jalisco, and Michoacan, 15 superior collections of
early, medium, and late-maturing materials were se-


elected for immediate distribution and as foundation
material for later development of superior synthetics
and hybrids. The improved yield of these materials
ranged from 15% to 160% above comparable local
varieties (Wellhausen 1947).
The Mexican-Rockefeller research group devel-
oped the composite variety, Rocamex V-7, by mass
selections in a collection from near Actopan, Hidalgo,
originally arising from a natural cross of cylindrical
dents from the lowland tropics with high-altitude maize
(conicos) from the Central Plateau (Wellhausen and
Roberts 1948). Several other varieties were developed
using this procedure (Roberts et al. 1949; Wellhausen
1950), as were those based on improved collections of
the Race, Olot6n (Neves et al. 1957).
Early hybrids released by the Mexican-Rockefeller
Program for tropical regions were Rocamex H-501,
H-502, H-503 (Reyes et al. 1955). These double-cross
hybrids were produced by crossing seven inbred lines
extracted from several populations of Tuxpeiio. Two of
the collections were from the State of Veracruz, one
from the State of Coahuila, and one from the State of
San Luis Potosf. The hybrids were all closely related.
One inbred (T3) was common in all three hybrids, and
two of the three lines were common to two hybrids. The
hybrids were reported to yield 20% to 25% more than
the open-pollinated varieties they were to replace.
Other hybrids were released for the higher elevations
of the Central Plateau. These were based largely on
inbred lines from the races Celaya and Bolita (Secre-
tariat de Agricultura 1955).

Maize Research Activities in Asia
During the 1950s, various other organi-
zations-USAID, FAO, USDA-also introduced a large
number of U.S. F1 hybrids into Asia. For the tropical
areas of Asia, the U.S. hybrids failed to gain a foothold.
First, the U.S. materials were not adapted to the
tropical and subtropical conditions of climate, dis-
eases, and insect pests. Second, the inbred lines in the
double crosses were generally too weak to withstand
the harsh production environments of tropical areas.
Third, the yellow dent grain of the U.S. hybrids was not
the preferred grain types. However, the U.S. Corn Belt
dents were used extensively in the temperate areas of
Asia; they were also used in subtropical and tropical
maize improvement programs to take advantage of
several desirable traits, though the gene frequency of
the temperate materials was usually less than 50%.










IMPROVED MAIZE VARIETIES AND HYBRIDS


In 1956, the Government of India and the Rockefeller
Foundation signed a memorandum of understanding
that was to have considerable significance for the
improvement of maize in Asia. The agreement pro-
vided for a cooperative effort in developing a post-
graduate school at the Indian Agricultural Research
Institute and for cereal improved work on several
crops, including maize. The maize improvement work
of the Rockefeller Foundation-Indian Agricultural
Program (RF-IAP) began in 1957 and made rapid
progress. By the early 1960s, the RF-IAP program was
receiving many requests from neighboring countries
for genetic stocks and research assistance. Clearly,
such international assistance was beyond the scope of
IAP. Therefore, a separate organization, the Inter-Asian
Corn Program (IACP) was established in 1964, with its
headquarters first in India and after 1966 in Thailand.
The IACP eventually included 16 countries stretch-
ing from Afghanistan to South Korea and operated
continuously from 1964 to 1975. Through IACP a large
amount of improved germplasm-mainly from the
Americas-was introduced into the national maize
programs of Asia during the 1960s. IACP regional
trials and nurseries began in 1969. These uniform yield
trials contained improved varieties and promising
breeding materials from participating national pro-
grams. Initially, most of the entries in the regional trials
came from India. Later, the Pakistani and Taiwanese
maize programs supplied outstanding subtropical
materials, and Thailand and the Philippines supplied
outstanding tropical materials (personal communica-
tions, T. Izuno and B.L. Renfro).

Exchanges of Breeding Material and
Informal Cooperative Networks
During the 1950s the exchange of breeding mate-
rial, lines, and synthetics between the joint
Rockefeller-Government maize programs in Mexico
and Colombia-as well as germplasm exchange with
maize programs elsewhere-led to identification of
selected germplasm that combined exceptionally well
with one another, e.g., ETO with Tuxpefio, and Mon-
tafia with Chalquefio and Tuxpeiio. Indeed, the results
of racial crosses in the Colombian program indicated
that the race Montafia, including Ecu 573 from Ecua-
dor, should combine well with germplasm in Kenya.
Therefore, Ecu 573 was sent from Colombia to Kenya
and crossed with Kitale II. It resulted in greatly in-
creased yields and formed the base for continued
improvement. Similarly, the Mexican program had
identified superior breeding materials for many parts


of the world. Many of these were races, improved
varieties, or composites of generally identifiable racial
backgrounds (Wellhausen 1978).
The influence of the Colombian and Mexican pro-
grams was particularly strong in Central America, and
to an appreciable degree in the Caribbean Basin. Initial
exchanges of breeding material and informal technical
cooperation led to increasingly close coordination of
breeding efforts and integration of material. Conse-
quently, numerous varieties, synthetics, and hybrids
were developed and distributed within these regions.
One of several important releases from this area was
Tiquisate Golden Yellow, having appreciable germplasm
from Cuba Oriente (personal communication, E.J.
Wellhausen and E. E. Gerrish). Tiquisate Golden
Yellow was widely grown in Thailand as "Guatemala"
and as "Metro" in Indonesia and the Philippines.
Yellow Salvadorefio was developed by mass selection
in a varietal cross of Yellow Tuxpan and Cuba PD. (MS)7
(Primera Reunion Centroamericana 1954). Both these
varieties were important in the later development of
Suwan-1, and Thai Composite #1 (personal communi-
cation, E. E. Gerrish).
These exchanges of information and breeding stocks,
accompanied by sometimes spectacular increases in
yield or improvement of other characteristics, led to an
informal network of exchange and collaboration. Most
often, an improved variety, or hybrid and its compo-
nent lines, was used on one side of a cross with locally
adapted material on the other. While many programs
were releasing varieties or synthetics, there was ample
opportunity to also release conventional or modified
hybrids when seed production capability was suitable.
The general trend of all this activity was greater aware-
ness of the genetic background and racial composition
of the breeding material.

Emerging Concepts of Germplasm
Use and Breeding Methods
Superior inbred lines, single crosses, or improved
varieties from one breeding program were often crossed
onto these same categories of breeding materials in
another area. This was expedient in the early stages of
many programs in order to obtain better material
rapidly for distribution to farmers. This also led to the
recognition of certain germplasm as clearly superior to
others. Consequently, superior germplasm was being
distributed widely in many areas of the world. It was
also becoming apparent that many parts of the world
could not, and should not, sustain a full-fledged hybrid
seed production and distribution program. Without a










IMPROVED MAIZE VARIETIES AND HYBRIDS


In 1956, the Government of India and the Rockefeller
Foundation signed a memorandum of understanding
that was to have considerable significance for the
improvement of maize in Asia. The agreement pro-
vided for a cooperative effort in developing a post-
graduate school at the Indian Agricultural Research
Institute and for cereal improved work on several
crops, including maize. The maize improvement work
of the Rockefeller Foundation-Indian Agricultural
Program (RF-IAP) began in 1957 and made rapid
progress. By the early 1960s, the RF-IAP program was
receiving many requests from neighboring countries
for genetic stocks and research assistance. Clearly,
such international assistance was beyond the scope of
IAP. Therefore, a separate organization, the Inter-Asian
Corn Program (IACP) was established in 1964, with its
headquarters first in India and after 1966 in Thailand.
The IACP eventually included 16 countries stretch-
ing from Afghanistan to South Korea and operated
continuously from 1964 to 1975. Through IACP a large
amount of improved germplasm-mainly from the
Americas-was introduced into the national maize
programs of Asia during the 1960s. IACP regional
trials and nurseries began in 1969. These uniform yield
trials contained improved varieties and promising
breeding materials from participating national pro-
grams. Initially, most of the entries in the regional trials
came from India. Later, the Pakistani and Taiwanese
maize programs supplied outstanding subtropical
materials, and Thailand and the Philippines supplied
outstanding tropical materials (personal communica-
tions, T. Izuno and B.L. Renfro).

Exchanges of Breeding Material and
Informal Cooperative Networks
During the 1950s the exchange of breeding mate-
rial, lines, and synthetics between the joint
Rockefeller-Government maize programs in Mexico
and Colombia-as well as germplasm exchange with
maize programs elsewhere-led to identification of
selected germplasm that combined exceptionally well
with one another, e.g., ETO with Tuxpefio, and Mon-
tafia with Chalquefio and Tuxpeiio. Indeed, the results
of racial crosses in the Colombian program indicated
that the race Montafia, including Ecu 573 from Ecua-
dor, should combine well with germplasm in Kenya.
Therefore, Ecu 573 was sent from Colombia to Kenya
and crossed with Kitale II. It resulted in greatly in-
creased yields and formed the base for continued
improvement. Similarly, the Mexican program had
identified superior breeding materials for many parts


of the world. Many of these were races, improved
varieties, or composites of generally identifiable racial
backgrounds (Wellhausen 1978).
The influence of the Colombian and Mexican pro-
grams was particularly strong in Central America, and
to an appreciable degree in the Caribbean Basin. Initial
exchanges of breeding material and informal technical
cooperation led to increasingly close coordination of
breeding efforts and integration of material. Conse-
quently, numerous varieties, synthetics, and hybrids
were developed and distributed within these regions.
One of several important releases from this area was
Tiquisate Golden Yellow, having appreciable germplasm
from Cuba Oriente (personal communication, E.J.
Wellhausen and E. E. Gerrish). Tiquisate Golden
Yellow was widely grown in Thailand as "Guatemala"
and as "Metro" in Indonesia and the Philippines.
Yellow Salvadorefio was developed by mass selection
in a varietal cross of Yellow Tuxpan and Cuba PD. (MS)7
(Primera Reunion Centroamericana 1954). Both these
varieties were important in the later development of
Suwan-1, and Thai Composite #1 (personal communi-
cation, E. E. Gerrish).
These exchanges of information and breeding stocks,
accompanied by sometimes spectacular increases in
yield or improvement of other characteristics, led to an
informal network of exchange and collaboration. Most
often, an improved variety, or hybrid and its compo-
nent lines, was used on one side of a cross with locally
adapted material on the other. While many programs
were releasing varieties or synthetics, there was ample
opportunity to also release conventional or modified
hybrids when seed production capability was suitable.
The general trend of all this activity was greater aware-
ness of the genetic background and racial composition
of the breeding material.

Emerging Concepts of Germplasm
Use and Breeding Methods
Superior inbred lines, single crosses, or improved
varieties from one breeding program were often crossed
onto these same categories of breeding materials in
another area. This was expedient in the early stages of
many programs in order to obtain better material
rapidly for distribution to farmers. This also led to the
recognition of certain germplasm as clearly superior to
others. Consequently, superior germplasm was being
distributed widely in many areas of the world. It was
also becoming apparent that many parts of the world
could not, and should not, sustain a full-fledged hybrid
seed production and distribution program. Without a









INTERNATIONAL GERMPLASM DEVELOPMENT


reliable supply of quality hybrid seed-and often no
funds or credit to purchase these materials-hybrid
maize use spread slowly in most maize-producing
countries, even though farmers recognized the yield
superiority of hybrids compared to their own varieties.
Beginning around the mid-1950s, there was grow-
ing awareness that the development of synthetic varie-
ties from superior germplasm could serve many
less-developed areas of the world. Breeding theory and
methodologies indicated that appreciable improve-
ment in maize could be attained by various recurrent
selection schemes. These procedures could be applied
to the existing superior germplasm stocks, varieties,
races or racial groups, and composites. Here, the
material from each breeding cycle has the potential of
being released directly as a variety. This would allow
for wide-scale distribution, even from farmer to farmer,
without suffering losses in yield or agronomic desira-
bility, and without having a sophisticated seed industry
in place. Additionally, the material from each breeding
cycle could also serve as an improved source from
which to extract inbred lines for hybrid seed production
to suit those areas having more advanced agricultural
capability.
The combination of the above events or circum-
stances led to increased understanding about germplasm
use. Certain lines or stocks were obviously valuable for
insect or disease resistance, or for other agronomic
characteristics in a particular situation. The outstand-
ing races, varieties, or germplasm complexes that
contributed greatly to yield were of complex back-
ground and genealogy. Diversity per se was no guaran-
tee in contributing to hybrid vigor or high yield poten-
tial. It was impossible to systematically test all the
maize collections to determine which would be most
advantageous to use under the myriad growing condi-
tions where maize was produced. Gradually, more
effort was put into developing improved populations,
as these could be used both in hybrid breeding pro-
grams as well as those concentrating on varietal devel-
opment. Obviously, the important constituents of these
programs were those races or germplasm complexes
already recognized as being exceptional. These in-
cluded ETO, Tuxpefio, Cuban Flint-Cateto, Coastal
Tropical Flints, Celaya, Pepitilla, Chalquefio, Tiqui-
sate, and Salvadoreiio, to name a few. In addition,
numerous studies of intervarietal crosses were under-
taken by the Rockefeller Foundation-Government
programs in Mexico and Colombia during the 1950s
and 1960s to determine which other races and varieties
would be most promising.


Refinements of Population
Improvement Methods
Various types of recurrent selection programs at
several locations in the Western Hemisphere were
proving successful for improving maize varieties or
germplasm complexes. Gains were shown for such
traits as grain yield, stronger stalks and root systems,
lowered plant and ear height, greater resistance to
some diseases and insect pests, certain other physio-
logical characteristics, and modifying environmental
adaptation. Recurrent selection procedures provided
many desirable features when applied to diverse
germplasm varieties, complexes, or composites. By the
1960s, a number of the breeding programs using these
techniques on widely grown varieties or on newly
constituted composites (genetic mixtures of varying
kinds and complexities) were obtaining appreciable
gains in the traits being selected. A number of out-
standing varieties were developed by the RF-Mexican
program. Among these were Tuxpeiio Crema I, Tuxpeiio
La Posta, and Tuxpeiio-1 (E. C. Johnson 1974 and
personal communication; E. J. Wellhausen 1978 and
personal communication).
These events were conducive to the thought that
compositing various germplasm sources such as varie-
ties, individual indigenous collections, racial complexes,
or elite breeding materials into new populations or
germplasm pools would be an effective method to
concentrate more desirable and diverse genes into
fewer numbers of breeding materials. Subsequent
population improvement by recurrent selection meth-
ods would then further concentrate the desired genes.
These populations could then be released as improved
varieties. Additionally, it was believed that these popu-
lations would serve as better sources of inbred lines (or
at least reduce the number of stocks to be worked on)
for hybrids than did the constituent individual stocks
used in the original admixtures or composites. Conse-
quently, there was considerable effort made in many
breeding programs-including by the International Maize
and Wheat Improvement Center (CIMMYT) and the
International Institute for Tropical Agriculture
(IITA)-to form composites from diverse germplasms.

ESTABLISHMENT OF
INTERNATIONAL MAIZE
IMPROVEMENT PROGRAMS

The successes of the Rockefeller Foundation, and
later the Ford Foundation, in their cooperative agricul-
tural programs in various Third World nations, led









INTERNATIONAL GERMPLASM DEVELOPMENT


reliable supply of quality hybrid seed-and often no
funds or credit to purchase these materials-hybrid
maize use spread slowly in most maize-producing
countries, even though farmers recognized the yield
superiority of hybrids compared to their own varieties.
Beginning around the mid-1950s, there was grow-
ing awareness that the development of synthetic varie-
ties from superior germplasm could serve many
less-developed areas of the world. Breeding theory and
methodologies indicated that appreciable improve-
ment in maize could be attained by various recurrent
selection schemes. These procedures could be applied
to the existing superior germplasm stocks, varieties,
races or racial groups, and composites. Here, the
material from each breeding cycle has the potential of
being released directly as a variety. This would allow
for wide-scale distribution, even from farmer to farmer,
without suffering losses in yield or agronomic desira-
bility, and without having a sophisticated seed industry
in place. Additionally, the material from each breeding
cycle could also serve as an improved source from
which to extract inbred lines for hybrid seed production
to suit those areas having more advanced agricultural
capability.
The combination of the above events or circum-
stances led to increased understanding about germplasm
use. Certain lines or stocks were obviously valuable for
insect or disease resistance, or for other agronomic
characteristics in a particular situation. The outstand-
ing races, varieties, or germplasm complexes that
contributed greatly to yield were of complex back-
ground and genealogy. Diversity per se was no guaran-
tee in contributing to hybrid vigor or high yield poten-
tial. It was impossible to systematically test all the
maize collections to determine which would be most
advantageous to use under the myriad growing condi-
tions where maize was produced. Gradually, more
effort was put into developing improved populations,
as these could be used both in hybrid breeding pro-
grams as well as those concentrating on varietal devel-
opment. Obviously, the important constituents of these
programs were those races or germplasm complexes
already recognized as being exceptional. These in-
cluded ETO, Tuxpefio, Cuban Flint-Cateto, Coastal
Tropical Flints, Celaya, Pepitilla, Chalquefio, Tiqui-
sate, and Salvadoreiio, to name a few. In addition,
numerous studies of intervarietal crosses were under-
taken by the Rockefeller Foundation-Government
programs in Mexico and Colombia during the 1950s
and 1960s to determine which other races and varieties
would be most promising.


Refinements of Population
Improvement Methods
Various types of recurrent selection programs at
several locations in the Western Hemisphere were
proving successful for improving maize varieties or
germplasm complexes. Gains were shown for such
traits as grain yield, stronger stalks and root systems,
lowered plant and ear height, greater resistance to
some diseases and insect pests, certain other physio-
logical characteristics, and modifying environmental
adaptation. Recurrent selection procedures provided
many desirable features when applied to diverse
germplasm varieties, complexes, or composites. By the
1960s, a number of the breeding programs using these
techniques on widely grown varieties or on newly
constituted composites (genetic mixtures of varying
kinds and complexities) were obtaining appreciable
gains in the traits being selected. A number of out-
standing varieties were developed by the RF-Mexican
program. Among these were Tuxpeiio Crema I, Tuxpeiio
La Posta, and Tuxpeiio-1 (E. C. Johnson 1974 and
personal communication; E. J. Wellhausen 1978 and
personal communication).
These events were conducive to the thought that
compositing various germplasm sources such as varie-
ties, individual indigenous collections, racial complexes,
or elite breeding materials into new populations or
germplasm pools would be an effective method to
concentrate more desirable and diverse genes into
fewer numbers of breeding materials. Subsequent
population improvement by recurrent selection meth-
ods would then further concentrate the desired genes.
These populations could then be released as improved
varieties. Additionally, it was believed that these popu-
lations would serve as better sources of inbred lines (or
at least reduce the number of stocks to be worked on)
for hybrids than did the constituent individual stocks
used in the original admixtures or composites. Conse-
quently, there was considerable effort made in many
breeding programs-including by the International Maize
and Wheat Improvement Center (CIMMYT) and the
International Institute for Tropical Agriculture
(IITA)-to form composites from diverse germplasms.

ESTABLISHMENT OF
INTERNATIONAL MAIZE
IMPROVEMENT PROGRAMS

The successes of the Rockefeller Foundation, and
later the Ford Foundation, in their cooperative agricul-
tural programs in various Third World nations, led









IMPROVED MAIZE VARIETIES AND HYBRIDS


..--' ,,i. ,- ,- --' --.l'il" .- .-_ ......._-' .-
-'-


Figure 4. A vivid demonstration of different plant heights resulting from experiments in
improving the grain to stover (stalks and leaves) ratio of Tuxpeiio Crema I maize. Tlaltizapan
Maize Breeding Station, Mexico. Source: CIMMYT.


these two foundations to seek ways to institutionalize
international agricultural research for basic food crops
in developing countries. In maize research, an interme-
diate step in this process was the establishment through
Rockefeller Foundation assistance of the Inter-American
Corn Program for Latin America in 1960 and the
Inter-Asian Corn Program for South and Southeast
Asia in 1964. With the establishment of the interna-
tional agricultural research centers, the Rockefeller
and Ford Foundations channeled more of their inter-
national food research efforts through these organiza-
tions and eventually discontinued their support for the
regional cooperative maize programs that had been
established in the early 1960s.
In 1971, under the sponsorship of the World Bank,
the United Nations Development Programme (UNDP),
and the U.N. Food and Agriculture Organization (FAO),
the Consultative Group for International Agricultural
Research (CGIAR) was formed to support an ex-
panded network of international agricultural research
centers (IARCs) modeled after the first four. The
CGIAR today consists of some 40 donor countries,


international and regional organizations, and private
foundations. It supports 13 nonprofit international
agricultural research and training centers that focus on
food production challenges in the Third World. In
pursuing their mandates, the IARCs seek to provide
national programs in developing countries with a range
of products and services, such as improved germplasm,
research procedures, training, consultation, and infor-
mation. CIMMYT and IITA operate diversified re-
search, training, and information programs designed
to support and complement the work of national maize
research programs.
At the time of their establishment in the 1960s,
CIMMYT, IITA, and the International Center for
Tropical Agriculture (CIAT) all had maize research
programs that were descendents of various Rockefeller
and Ford Foundation bilateral maize research efforts
with developing country governments. Among the three
IARCs, CIMMYT had the largest maize research
program and considered that it had a worldwide man-
date for maize improvement. In the early 1970s, CIAT
opted to discontinue its maize improvement work and









INTERNATIONAL GERMPLASM DEVELOPMENT


to rely on CIMMYT to supply improved maize
germplasm to national programs in Latin America.
The interest that CIAT did retain in maize was primar-
ily concerned with its frequent intercropping associa-
tion with climbing field beans (one of the CIAT man-
dated crops). In contrast, IITA has expanded its maize
improvement program from an initial focus on the
lowland humid tropics of sub-Saharan Africa to in-
clude intermediate-altitude regions of tropical Africa.
In recent years, CIMMYT and IITA have sought to
improve their research coordination and collaboration
between their respective maize improvement efforts in
Africa. In 1980, two CIMMYT maize breeders were
assigned at IITA to collaborate in the conversion of
high-yielding varieties adapted to the lowland tropical
areas to streak-resistant versions, and in increasing the
streak resistance of Population 43, La Posta, a late,
white dent material with good performance in
sub-Saharan Africa. In 1985, CIMMYT and IITA also
agreed to collaborate in a new joint germplasm im-
provement effort for the mid-elevation ecologies of
eastern and southern Africa, in association with the
University of Zimbabwe at Harare. (IITA has recently
withdrawn from formal involvement as part of a new
agreement with CIMMYT concerning regional divi-
sion of responsibilities but will continue to be infor-
mally involved.) This program is using germplasm
sources developed by IITA, CIMMYT, and various
national programs.



CIMMYT's International Maize
Improvement Program
In CIMMYT's early years, there was a carryover of
personnel, breeding materials, and philosophies from
the Mexican Government-Rockefeller Foundation
program. But with their new international "mandate"
the RF-Mexican maize team in Mexico took on new
research responsibilities, added staff, and expanded
the scope of their breeding materials and germplasm
development objectives. From this milieu the concept
evolved that CIMMYT would develop composites,
improved populations, and varieties that could be used
directly by national programs as varieties or as breed-
ing sources for hybrids.
Using recurrent selection methods, CIMMYT began
forming numerous composites of germplasm with dif-
ferent grain types and color for use in broad ecological
zones. Some of the composites were formed indis-


criminately; others were formed systematically on the
basis of replicated trials; others on the basis of race,
racial relationship, phenotypic characters, knowledge
of the performance of related materials, and intuition
(personal communication, E.C. Johnson, J.H. Lon-
quist, and EJ. Wellhausen). By the early 1980s, how-
ever, CIMMYT's selection schemes had become more
formalized (Vasal et al. 1982).
Unfortunately, the exact kinds and amounts of each
germplasm component used to make the composites
or gene pools when the particular strain, line, variety,
or other entity was incorporated-and the precise
methodology employed at each step along the way-are
not known. In some cases, these events could possibly
be determined from field books and the recollections
of those involved, but in other cases it is improbable
that a satisfactory reconstruction of the methods and
materials used could be made (personal communica-
tion, E.C. Johnson, E.J. Wellhausen). Generally in
these matters, CIMMYT's published accounts are too
vague to be of much value in tracing germplasm flow,
breeding history, or determining precisely the constitu-
ents of a gene pool or population, except in a broad
overview.
CIMMYT's Maize Improvement Program has
assembled and improved a broad range of germplasm
complexes. Using a half-sib recurrent selection breed-
ing methodology and fairly mild selection pressure,
CIMMYT has developed 24 normal maize and 13
quality protein maize (QPM) gene pools, classified
according to zone of adaptation, maturity period, and
grain type and color. (The QPM work has recently
been evaluated in NRC 1988.) These gene pools have
been assembled from CIMMYTs germplasm bank-with
more than 10,000 collections mostly from Latin
America-and germplasm supplied by maize scientists
from other research programs around the world. Using
the most promising germplasm in these gene pools and
from other sources, CIMMYT has derived 24 normal
and 10 QPM advanced populations that are suited to a
range of climatic conditions (tropical, subtropical,
temperate), maturity periods (early, intermediate, late);
grain color (yellow, white); and kernel type (flint, dent,
floury). See table 1 for details.
In a continuous cyclical process, CIMMYT's pools
and populations undergo improvement for yield poten-
tial, protein quality, agronomic type, disease and insect
resistance, and tolerance to stresses such as drought
and aluminum toxicity. In Mexico, these materials are
screened for resistance to major foliar diseases, stalk









IMPROVED MAIZE VARIETIES AND HYBRIDS





-,M^- ;f nr -


Figure 5. Dr. Surinder K. Vasal, CIMMYT plant breeder, who played a major role in developing
quality protein maize. Source: CIMMYT.


and ear rots, and various ear and stalk borers. Addi-
tional disease screening for downy mildew, corn stunt,
and maize streak virus is carried out through collabo-
rative research projects with institutions located in
areas outside Mexico that are more conducive to this
work. Improved genetic sources for specific resistances
to various diseases and insects and for tolerance to
certain environmental stresses associated with drought,
cold, heat, and acid soils are also being developed.
CIMMYT's germplasms are made available to
cooperators in national programs through informal
sharing of germplasm from either the pools or popula-
tions and through the more formalized international
maize testing program, which included International
Progeny Testing Trials (IPTTs), Experimental Variety
Trials (EVTs), and Elite Experimental Variety Trails
(ELVTs). This international testing program presently


involves cooperation with scientists in more than 80
countries, and each year, over 700 trials are shipped for
testing at several hundred locations.
Currently, in each IPTT, the full-sib progenies of a
particular population are tested at up to six locations
around the world. In a given year, about 15 populations
are tested. The results of those trials are used for two
purposes. First, based upon information provided by
the trial cooperators, CIMMYT breeders select the
best 50 to 60 families for within-family improvement,
recombination, and regeneration of each population
for the next testing cycle. The second use of the IPTT
results is for the development of experimental varieties
(EVs). Site-specific EVs are derived from the best 10
families at each IPTT location. An across-location EV
is also formed using the 10 best families across all IPTT
locations. These varieties are advanced to the F2 stage









INTERNATIONAL GERMPLASM DEVELOPMENT


Table 1. CIMMYT's advanced normal and quality
protein maize populations tested regularly in
international progeny testing trials


Population
number Name Description


Tuxpefio-1
Mezcla Tropical Blanca
Blanco Cristalino-1
Antigua-Veracruz 181
Blanco Cristalino-3
Mezcla Amarilla
Amarillo Cristalino-1
Amarillo Dentado
Tuxpefio Caribe
Blanco Cristalino-2
Amarillo Cristalino-2
ETO Blanco
Amarillo Subtropical
Blanco Subtropical
Antigua-Rep. Domin.
Cogollero

ETO-Illinois
La Posta
Am. Early Dent-Tuxpefio
Amarillo Bajio
Temp. Amarillo Crist.
Temp. Blanco Dentado-2
Compuesto de Hugaria
Blanco Dentado-2

Early Yellow Flint QPM
White Flint QPM
Blanco Dentado-1 QPM
Blanco Dentado-2 QPM
Yellow Flint QPM
Yellow Dent QPM
Temp. Blanco Crist. QPM
Temp Blanco Dent. QPM
Templado Amarillo QPM
Temp. Amarillo Dent. QPM


TLWD
TLWD
TIWD
TLYD
TLWF
TIYF
TIYF
TLYD
TLWD
TEWF
TEYF
SIWF
SIYF
SLWD
TIYD
TIYD

SLWD
TLWD
SLWD
SIYD
SEYF
SIWD
TeEID
TIWD

TEYF
TLWF
TLWD
TLWD
TLYF
TLYD
SLWD
SIWD
SIYD
SIYD


and dispatched to cooperators in the form of an Ex-
perimental Variety Trial (EVT), each of which is
evaluated at 30 to 50 locations worldwide. After the
data from these trials have been analyzed, CIMMYT
selects the top-performing EVs to prepare Elite Ex-
perimental Variety Trials (ELVTs), which are distrib-
uted to from 60 to 80 locations and conducted in much
the same way as the EVTs.
Although the development of pools, populations,
and open-pollinated varieties will remain a central
feature of the CIMMYT maize program, in 1985
CIMMYT established a hybrid development program
in response to growing national program requests for
research collaboration and assistance. Information is
being generated about inbreeding depression and
heterotic patterns of CIMMYT's broad-based gene
pools and populations. IITA has provided CIMMYT
with over 500 inbred lines from its hybrid program.
The 1980s have also seen an evolution in the breed-
ing programs of CIMMYT. More attention is being
placed on developing new source populations with
resistance and/or tolerance to specific problems: in-
sects, diseases, drought stress, and mineral toxicities.
In many cases, CIMMYT's new source populations are
being developed using the superior fractions (for a
specific trait) of CIMMYT standard populations.
CIMMYT has also increased its work in germplasm
development for highland areas (above 1,800 m) and
for intermediate elevations (1,200 to 1,800 m) (in
collaboration with the University of Zimbabwe).

IITA's Maize Improvement Program

The maize improvement program at the Interna-
tional Institute for Tropical Agriculture (IITA) in
Ibadan, Nigeria, was initiated in the early 1970s. Its
major objective has been to develop high-yielding
germplasm with increased yield dependability by
emphasizing resistance breeding through recurrent
selection. Initially, efforts were devoted mainly to
developing improved germplasm with resistance to
Puccinia polysora and Helminthosporium maydis for
the lowland humid tropics. Two late-maturing white
populations were developed initially: TZB (African
and Latin American sources with Nigerian Composite
B as the most important component) and TZPB (de-
rived from CIMMYT's Tuxpefio Planta Baja Cycle 7).
Varieties developed from these two populations have
been released in Nigeria, Cameroon, Gabon, and Benin.
In 1975, work was initiated to develop germplasm
with resistance to Maize Streak Virus (MSV), a disease
currently confined to the African continent. This re-


Key

T = Tropical L = Late maturity
S = Subtropical I = Intermediate maturity
Te = Temperate E = Early maturity

F = Flint QPM = Quality protein maize
D = Dent Y = Yellow








IMPROVED MAIZE VARIETIES AND HYBRIDS


Figure 6. Testing of IITA inbred lines, for use in
developing hybrid varieties, at a savanna station in
Nigeria. Source: CIMMYT.


search effort has been the major aim of the IITA maize
program during the last decade (IITA 1986a). MSV is
one of the most economically important diseases in
Africa. It occurs over a wide range of ecologies, from
sea level to 1,800 m elevation and from the humid
forest zone to the dry savanna. Yield losses of up to
100% due to MSV have been recorded in manyAfrican
countries. Because of the erratic natural occurrence of
MSV, it was necessary to develop an artificial
mass-rearing facility for the vector, Cicadulina spp.,
and techniques for uniform infestation in the field.
Through this screening program, two sources of resis-
tance were identified: the variety TZ-Y from IITA and
the variety La Revolution developed by the French
Tropical Agricultural Research Institute (IRAT) at
Reunion Island. These two sources have been used to
develop multigenic resistance to MSV. While resistant
plants are not immune, they show reduced symptoms
of MSV.


After the discovery of MSV resistance, an intensive
breeding program was initiated to develop resistant
germplasm (populations, varieties, and inbred lines)
with different ecological adaptation, maturity, grain
color, and texture. TZSR-W and TZSR-Y, late white
and yellow semiflint populations adapted to the low-
land tropics, respectively, were the first improved
populations with MSV resistance developed at IITA.
Since 1980, CIMMYT has also posted one or two
maize breeders at Ibadan to work with IITA scientists
in the conversion of additional germplasm to
streak-resistant types. In addition to developing new
streak-resistant populations to serve additional ecolo-
gies, the CIMMYT-ITA collaborative program has
converted, through backcrossing, over 30 experimental
varieties from more than a dozen existing CIMMYT
populations that are well-adapted to African maize
production conditions. Streak resistance is also being
incorporated into some of the most widely grown
commercial varieties from African countries through a
backcrossing conversion program. Today, many
streak-resistant maize materials are being made avail-
able to national programs through IITA's international
testing program.
In 1979, IITA initiated a tropical hybrid develop-
ment program to produce adapted, disease-resistant
inbred lines with good combining ability for use by
national maize programs in hybrid and synthetic vari-
ety development. The hybrid program was expanded in
1982 through a special project funded by the Govern-
ment of Nigeria; it subsequently evolved into a joint
IITA-Nigeria hybrid program. IITA is now giving more
attention to transferring hybrid technology to other
interested African countries such as Cameroon, Ghana,
and C6te d'Ivoire.
A number of outstanding hybrids for tropical areas
have been developed through this research effort (IITA
1986b). These materials are made available to national
maize researchers through two international hybrid
trials (white and yellow) that are distributed through-
out Africa and in a growing number of countries of
Asia and Latin America. Commercial production of
these hybrids is already under way in Nigeria.
In addition to its work in hybrid development and
the breeding for MSV resistance, IITA's maize im-
provement program has also concentrated on five
other priority research areas:
1. Combined resistance to MSVand downy mildew.
While downy mildew, Peronosclerospora spp., is not
widespread in Africa, areas infested with downy mil-
dew generally overlap those subject to streak virus









INTERNATIONAL GERMPLASM DEVELOPMENT


attack. White and yellow populations with combined
resistance to the two diseases have been developed
using downy mildew resistant sources from Thailand
and the Philippines. These materials have been crossed
with streak-resistant adapted materials. The level of
resistance to the two diseases is high, and preliminary
experiments have shown that the resistant materials
have good yield potential. Inbred lines and hybrids with
combined resistance to MSV and downy mildew are
being developed; some of these materials are currently
being used in Thailand and the Philippines (personal
communication, S.K. Kim).
2. Resistance to stem borers. Work is in progress on
resistance to the two major stem borers species found
in West Africa: Sesamia calamistis and Eldana sac-
charina. Development of suitable artificial insect rear-
ing and infestation techniques is still under way and
little research impact has been achieved to date.
3. Drought tolerance. Breeding for drought toler-
ance was initiated in 1982 in Burkina Faso through the
SAFGRAD/IITA collaborative project. (CIMMYT
also participates in this work.) Breeding for early- and
extra-early-maturing germplasm is emphasized, with
agronomic research also being an important compo-
nent. Issues of water conservation, soil fertility, and soil
compaction are the major topics in the agronomy
research program.
4. Resistance to Striga spp. This parasitic weed is
becoming a serious problem in the expanding
maize-growing areas of the African savanna. A good
level of resistance has already been identified among


different germplasm sources indicating that breeding
for Striga resistance is possible. A number of sites with
a high level of natural infestation have been identified
as locations for screening. Work has also begun to
develop laboratory techniques for artificial infestation.
5. Breeding for the mid-altitudes. The mid-altitude
ecologies of sub-Saharan Africa have some of highest
yield potential. Germplasm requirements for these
zones included resistance to leaf blight (H. turcicum),
rust (P. sorghi) and MSV. In 1978, IITA began to
develop maize populations with resistance to these
diseases, and these populations have been tested in 20
countries. In 1985, CIMMYT, IITA, and the University
of Zimbabwe, Harare, launched a collaborative
mid-altitude germplasm development program for
maize-growing areas in eastern and southern Africa
between 1,200 and 1,800 m elevation. Improved
populations, inbred lines, and open-pollinated varie-
ties with enhanced disease resistance for mid-altitude
ecologies are being developed through this joint pro-
gram. (As noted earlier, IITA has recently withdrawn
from formal involvement as part of a new agreement
with CIMMYT concerning regional division of respons-
ibilities but will continue to be informally involved.)
While the programs outlined in this chapter are, in
the first instance, designed to help developing nations,
the genetic products may also prove to be of value in
breeding programs in developed nations. One ex-
ample of the potential is provided in a recent article by
Holley and Goodman. (The abstract is reproduced in
appendix B.)



















3. RECENT RELEASES AND USE OF

IMPROVED MAIZE MATERIALS


This chapter provides a preliminary status report of
the recent releases and uses of open-pollinated varie-
ties and hybrids in 57 developing countries. The coun-
try reports probably overemphasize the germplasm
contributions of CIMMYT, IITA, and predecessor
international programs, such as those of the Rockefeller
Foundation. This is primarily because more informa-
tion is readily available from these international or-
ganizations than from national programs. It is hoped
that future efforts to trace the use and impact of
improved maize genotypes will help to fill in the infor-
mational gaps that are contained in this report.

SUB-SAHARAN AFRICA

Eastern and Southern Africa

ETHIOPIA
Maize is produced throughout Ethiopia in temper-
ate as well as tropical environments, with the bulk of
production concentrated in the southern, southwest-
ern, and western regions. During 1983-85, approxi-
mately 1.2 million t of grain were produced annually on
850,000 ha, with national yields averaging 1.4 t/ha.
Among the major cereals, maize ranks first in total
production and in yield; it ranks fourth in total area
behind Tef (Eragrostis abyssinica), barley, and sor-
ghum. Almost all of the maize produced is used for
human consumption.
Maize research is conducted by the Institute of
Agricultural Research (IAR) and by the College of
Agriculture (Debelo 1985). Both CIMMYT and IITA
report collaboration with national scientists. Germplasm
development efforts are directed toward the produc-
tion requirements of three major zones: (1) areas with
a short rainy season or erratic rainfall requiring


early-maturing and/or drought-tolerant materials, (2)
areas with additional rainfall requiring
intermediate-maturity materials, and (3) late-maturing
materials suitable for areas with a long growing season
and ample rainfall. Breeding efforts to meet the needs
of these different moisture regimes include the devel-
opment of open-pollinated varieties as well as hybrids
with resistance to H. turcicum and P. sorghi. An
early-maturing, open-pollinated variety developed from
this work was submitted in 1985 to the National Variety
Release Committee for final approval.
A national seed program was implemented in 1978
with the establishment of the Ethiopian Seed Corpora-
tion (ESC). Large-scale seed production and distribu-
tion has been carried out since 1980. In 1985, the ESC
reported seed sales of 11.8 t; of this total, 7.5 t was
commercial seed, not certified but field approved.
IITAreports supplying the ESC with t of TZSR-1 and
200 kg of TZESR-W for multiplication and distribu-
tion to farmers in a new settlement area where maize
streak virus is widely present (personal communica-
tion, Y. Efron). The ESC also has initiated production
of two hybrids (8321-18 and 8322-13) developed at
IITA.

KENYA
Maize is the major staple for Kenya's population,
and more than 90% of this maize is produced by
small-scale farmers. During 1983-85, approximately
2.4 million t of grain were produced annually on 1.5
million ha, with national yields averaging 1.5 t/ha. In
addition, some 100,000 t of maize were imported annu-
ally during 1982-84.
Maize research in Kenya began in colonial times
and has continued to evolve since independence.
Germplasm development is directed toward four ma-
jor agroecological zones (Ochieng 1985):









IMPROVED MAIZE VARIETIES AND HYBRIDS


Figure 7. Ear of hybrid maize developed in Kenya. Source: A.I.D.


1. High-potential zone, unimodal rainfall pattern
(1,000 to 2,200 mm), 1,600 to 2,300 m altitude
2. Medium-potential zone, bimodal rainfall pattern
(700 to 1,800 mm), 1,000 to 1,700 m altitude
3. Low-potential zone, scanty, short-duration rains
4. Coastal strip, hot, humid belt, some saline soils
During the 1950s, local maize landraces-tracing to
probable affinities with Tuxpeflo-Hickory King taken
to southern Africa in the 19th century, then selected
over generations for adaptation as the crop slowly
moved north-were gathered from farmers' fields. These
materials were used to develop composite populations
to form the basic breeding stocks. However, because
the germplasm base had been markedly narrowed
through selection, efforts to improve this material met
with little success, and local breeders looked for new
sources of genetic diversity.
In the late 1950s, new exotic germplasm, notably
Ecuador 573 and Costa Rica 76, was introduced into
the breeding stocks, and a search began for maizes with
heterosis in crosses with local strains. During the
1960s, inbreeding and hybridization with local materi-


als were carried out and the first hybrids were released.
Several improved varieties and conventional hybrids
were made available to farmers: Kitale II and hybrids
H 631, H 621, and H 622. Also, a variety cross H 611
(KII x Ecu 573) was released for commercial use.
A maize breeding program was undertaken at
Kitale, Kenya, as part of the U.S. cooperation with the
East African Agriculture and Forestry Research Or-
ganization (EAAFRO). To strengthen this cereal
improvement research, the U.S. Agency for Interna-
tional Development and the U.S. Department of Agri-
culture agreed in 1963 to cooperate in a Major Cereals
Project in Africa, which included Kenya (Eberhart and
Sprague 1973; Johnson et al. 1980). The USAID-USDA
Program set up a comprehensive breeding system
using two composites (Comp. B and Comp. R) which
were improved by recurrent selection.
Since 1963, more than a dozen open-pollinated
varieties and composites and various types of hybrids
have been released for commercial production (table
2). Hybrid maize has become so popular in Kenya that
most farmers in the more favored production areas will



















3. RECENT RELEASES AND USE OF

IMPROVED MAIZE MATERIALS


This chapter provides a preliminary status report of
the recent releases and uses of open-pollinated varie-
ties and hybrids in 57 developing countries. The coun-
try reports probably overemphasize the germplasm
contributions of CIMMYT, IITA, and predecessor
international programs, such as those of the Rockefeller
Foundation. This is primarily because more informa-
tion is readily available from these international or-
ganizations than from national programs. It is hoped
that future efforts to trace the use and impact of
improved maize genotypes will help to fill in the infor-
mational gaps that are contained in this report.

SUB-SAHARAN AFRICA

Eastern and Southern Africa

ETHIOPIA
Maize is produced throughout Ethiopia in temper-
ate as well as tropical environments, with the bulk of
production concentrated in the southern, southwest-
ern, and western regions. During 1983-85, approxi-
mately 1.2 million t of grain were produced annually on
850,000 ha, with national yields averaging 1.4 t/ha.
Among the major cereals, maize ranks first in total
production and in yield; it ranks fourth in total area
behind Tef (Eragrostis abyssinica), barley, and sor-
ghum. Almost all of the maize produced is used for
human consumption.
Maize research is conducted by the Institute of
Agricultural Research (IAR) and by the College of
Agriculture (Debelo 1985). Both CIMMYT and IITA
report collaboration with national scientists. Germplasm
development efforts are directed toward the produc-
tion requirements of three major zones: (1) areas with
a short rainy season or erratic rainfall requiring


early-maturing and/or drought-tolerant materials, (2)
areas with additional rainfall requiring
intermediate-maturity materials, and (3) late-maturing
materials suitable for areas with a long growing season
and ample rainfall. Breeding efforts to meet the needs
of these different moisture regimes include the devel-
opment of open-pollinated varieties as well as hybrids
with resistance to H. turcicum and P. sorghi. An
early-maturing, open-pollinated variety developed from
this work was submitted in 1985 to the National Variety
Release Committee for final approval.
A national seed program was implemented in 1978
with the establishment of the Ethiopian Seed Corpora-
tion (ESC). Large-scale seed production and distribu-
tion has been carried out since 1980. In 1985, the ESC
reported seed sales of 11.8 t; of this total, 7.5 t was
commercial seed, not certified but field approved.
IITAreports supplying the ESC with t of TZSR-1 and
200 kg of TZESR-W for multiplication and distribu-
tion to farmers in a new settlement area where maize
streak virus is widely present (personal communica-
tion, Y. Efron). The ESC also has initiated production
of two hybrids (8321-18 and 8322-13) developed at
IITA.

KENYA
Maize is the major staple for Kenya's population,
and more than 90% of this maize is produced by
small-scale farmers. During 1983-85, approximately
2.4 million t of grain were produced annually on 1.5
million ha, with national yields averaging 1.5 t/ha. In
addition, some 100,000 t of maize were imported annu-
ally during 1982-84.
Maize research in Kenya began in colonial times
and has continued to evolve since independence.
Germplasm development is directed toward four ma-
jor agroecological zones (Ochieng 1985):



















3. RECENT RELEASES AND USE OF

IMPROVED MAIZE MATERIALS


This chapter provides a preliminary status report of
the recent releases and uses of open-pollinated varie-
ties and hybrids in 57 developing countries. The coun-
try reports probably overemphasize the germplasm
contributions of CIMMYT, IITA, and predecessor
international programs, such as those of the Rockefeller
Foundation. This is primarily because more informa-
tion is readily available from these international or-
ganizations than from national programs. It is hoped
that future efforts to trace the use and impact of
improved maize genotypes will help to fill in the infor-
mational gaps that are contained in this report.

SUB-SAHARAN AFRICA

Eastern and Southern Africa

ETHIOPIA
Maize is produced throughout Ethiopia in temper-
ate as well as tropical environments, with the bulk of
production concentrated in the southern, southwest-
ern, and western regions. During 1983-85, approxi-
mately 1.2 million t of grain were produced annually on
850,000 ha, with national yields averaging 1.4 t/ha.
Among the major cereals, maize ranks first in total
production and in yield; it ranks fourth in total area
behind Tef (Eragrostis abyssinica), barley, and sor-
ghum. Almost all of the maize produced is used for
human consumption.
Maize research is conducted by the Institute of
Agricultural Research (IAR) and by the College of
Agriculture (Debelo 1985). Both CIMMYT and IITA
report collaboration with national scientists. Germplasm
development efforts are directed toward the produc-
tion requirements of three major zones: (1) areas with
a short rainy season or erratic rainfall requiring


early-maturing and/or drought-tolerant materials, (2)
areas with additional rainfall requiring
intermediate-maturity materials, and (3) late-maturing
materials suitable for areas with a long growing season
and ample rainfall. Breeding efforts to meet the needs
of these different moisture regimes include the devel-
opment of open-pollinated varieties as well as hybrids
with resistance to H. turcicum and P. sorghi. An
early-maturing, open-pollinated variety developed from
this work was submitted in 1985 to the National Variety
Release Committee for final approval.
A national seed program was implemented in 1978
with the establishment of the Ethiopian Seed Corpora-
tion (ESC). Large-scale seed production and distribu-
tion has been carried out since 1980. In 1985, the ESC
reported seed sales of 11.8 t; of this total, 7.5 t was
commercial seed, not certified but field approved.
IITAreports supplying the ESC with t of TZSR-1 and
200 kg of TZESR-W for multiplication and distribu-
tion to farmers in a new settlement area where maize
streak virus is widely present (personal communica-
tion, Y. Efron). The ESC also has initiated production
of two hybrids (8321-18 and 8322-13) developed at
IITA.

KENYA
Maize is the major staple for Kenya's population,
and more than 90% of this maize is produced by
small-scale farmers. During 1983-85, approximately
2.4 million t of grain were produced annually on 1.5
million ha, with national yields averaging 1.5 t/ha. In
addition, some 100,000 t of maize were imported annu-
ally during 1982-84.
Maize research in Kenya began in colonial times
and has continued to evolve since independence.
Germplasm development is directed toward four ma-
jor agroecological zones (Ochieng 1985):



















3. RECENT RELEASES AND USE OF

IMPROVED MAIZE MATERIALS


This chapter provides a preliminary status report of
the recent releases and uses of open-pollinated varie-
ties and hybrids in 57 developing countries. The coun-
try reports probably overemphasize the germplasm
contributions of CIMMYT, IITA, and predecessor
international programs, such as those of the Rockefeller
Foundation. This is primarily because more informa-
tion is readily available from these international or-
ganizations than from national programs. It is hoped
that future efforts to trace the use and impact of
improved maize genotypes will help to fill in the infor-
mational gaps that are contained in this report.

SUB-SAHARAN AFRICA

Eastern and Southern Africa

ETHIOPIA
Maize is produced throughout Ethiopia in temper-
ate as well as tropical environments, with the bulk of
production concentrated in the southern, southwest-
ern, and western regions. During 1983-85, approxi-
mately 1.2 million t of grain were produced annually on
850,000 ha, with national yields averaging 1.4 t/ha.
Among the major cereals, maize ranks first in total
production and in yield; it ranks fourth in total area
behind Tef (Eragrostis abyssinica), barley, and sor-
ghum. Almost all of the maize produced is used for
human consumption.
Maize research is conducted by the Institute of
Agricultural Research (IAR) and by the College of
Agriculture (Debelo 1985). Both CIMMYT and IITA
report collaboration with national scientists. Germplasm
development efforts are directed toward the produc-
tion requirements of three major zones: (1) areas with
a short rainy season or erratic rainfall requiring


early-maturing and/or drought-tolerant materials, (2)
areas with additional rainfall requiring
intermediate-maturity materials, and (3) late-maturing
materials suitable for areas with a long growing season
and ample rainfall. Breeding efforts to meet the needs
of these different moisture regimes include the devel-
opment of open-pollinated varieties as well as hybrids
with resistance to H. turcicum and P. sorghi. An
early-maturing, open-pollinated variety developed from
this work was submitted in 1985 to the National Variety
Release Committee for final approval.
A national seed program was implemented in 1978
with the establishment of the Ethiopian Seed Corpora-
tion (ESC). Large-scale seed production and distribu-
tion has been carried out since 1980. In 1985, the ESC
reported seed sales of 11.8 t; of this total, 7.5 t was
commercial seed, not certified but field approved.
IITAreports supplying the ESC with t of TZSR-1 and
200 kg of TZESR-W for multiplication and distribu-
tion to farmers in a new settlement area where maize
streak virus is widely present (personal communica-
tion, Y. Efron). The ESC also has initiated production
of two hybrids (8321-18 and 8322-13) developed at
IITA.

KENYA
Maize is the major staple for Kenya's population,
and more than 90% of this maize is produced by
small-scale farmers. During 1983-85, approximately
2.4 million t of grain were produced annually on 1.5
million ha, with national yields averaging 1.5 t/ha. In
addition, some 100,000 t of maize were imported annu-
ally during 1982-84.
Maize research in Kenya began in colonial times
and has continued to evolve since independence.
Germplasm development is directed toward four ma-
jor agroecological zones (Ochieng 1985):



















3. RECENT RELEASES AND USE OF

IMPROVED MAIZE MATERIALS


This chapter provides a preliminary status report of
the recent releases and uses of open-pollinated varie-
ties and hybrids in 57 developing countries. The coun-
try reports probably overemphasize the germplasm
contributions of CIMMYT, IITA, and predecessor
international programs, such as those of the Rockefeller
Foundation. This is primarily because more informa-
tion is readily available from these international or-
ganizations than from national programs. It is hoped
that future efforts to trace the use and impact of
improved maize genotypes will help to fill in the infor-
mational gaps that are contained in this report.

SUB-SAHARAN AFRICA

Eastern and Southern Africa

ETHIOPIA
Maize is produced throughout Ethiopia in temper-
ate as well as tropical environments, with the bulk of
production concentrated in the southern, southwest-
ern, and western regions. During 1983-85, approxi-
mately 1.2 million t of grain were produced annually on
850,000 ha, with national yields averaging 1.4 t/ha.
Among the major cereals, maize ranks first in total
production and in yield; it ranks fourth in total area
behind Tef (Eragrostis abyssinica), barley, and sor-
ghum. Almost all of the maize produced is used for
human consumption.
Maize research is conducted by the Institute of
Agricultural Research (IAR) and by the College of
Agriculture (Debelo 1985). Both CIMMYT and IITA
report collaboration with national scientists. Germplasm
development efforts are directed toward the produc-
tion requirements of three major zones: (1) areas with
a short rainy season or erratic rainfall requiring


early-maturing and/or drought-tolerant materials, (2)
areas with additional rainfall requiring
intermediate-maturity materials, and (3) late-maturing
materials suitable for areas with a long growing season
and ample rainfall. Breeding efforts to meet the needs
of these different moisture regimes include the devel-
opment of open-pollinated varieties as well as hybrids
with resistance to H. turcicum and P. sorghi. An
early-maturing, open-pollinated variety developed from
this work was submitted in 1985 to the National Variety
Release Committee for final approval.
A national seed program was implemented in 1978
with the establishment of the Ethiopian Seed Corpora-
tion (ESC). Large-scale seed production and distribu-
tion has been carried out since 1980. In 1985, the ESC
reported seed sales of 11.8 t; of this total, 7.5 t was
commercial seed, not certified but field approved.
IITAreports supplying the ESC with t of TZSR-1 and
200 kg of TZESR-W for multiplication and distribu-
tion to farmers in a new settlement area where maize
streak virus is widely present (personal communica-
tion, Y. Efron). The ESC also has initiated production
of two hybrids (8321-18 and 8322-13) developed at
IITA.

KENYA
Maize is the major staple for Kenya's population,
and more than 90% of this maize is produced by
small-scale farmers. During 1983-85, approximately
2.4 million t of grain were produced annually on 1.5
million ha, with national yields averaging 1.5 t/ha. In
addition, some 100,000 t of maize were imported annu-
ally during 1982-84.
Maize research in Kenya began in colonial times
and has continued to evolve since independence.
Germplasm development is directed toward four ma-
jor agroecological zones (Ochieng 1985):








RECENT RELEASES


Table 2. Maize varieties released by
Kenyan National Breeding Programs

Year of Yield
Variety Typeb release (% of KSM)
KSM OP 100
ECU 573 OP 1959 -
KS II OP 1961 107
H 611 VC 1964 142
H 621 DC 1964 132
H 631 TWC 1964 140
H 622 DC 1965 135
H 632 TWC 1965 140
H 612 TC 1966 155
KCB OP 1967 -
H 511 VC 1967
H 512 VC 1970 -
H 611C VC 1971 155
H 613 TC 1972 166
CMC OP 1974
H 614 TC 1976 166
H625 DC 1981 176

Source: Ochieng 1985
aKCB = Katumaini Composite B; CMC = Coastal
Maize Composite;
bOP = open-pollinatedvariety; VC = variety cross;
DC = double-cross hybrid; TWC = three- way cross
hybrid; TC = top-cross hybrid


not accept anything else. Between 1963 and 1981, the
hybrid area has increased from zero to nearly 600,000
ha. Until the late 1960s, large-scale farmers dominated
the use ofhybrids; since then, the number of small-scale
farmers has increased greatly.
Maize materials from both CIMMYT and IITA
continue to be evaluated by national maize program
scientists. Some have been used for the development of
several experimental hybrids yet to be released. Al-
though CIMMYT populations and pools are generally
susceptible to common rust and turcicum blight, some
are being used in the breeding program. CIMMYT
Populations 21 (Tuxpefio-1), 49 (Blanco Dentado-2),
and 32 (ETO Blanco) have been used in the develop-
ment of several varietal hybrids in Kenya: PWAN-1,
H-1, H-2, and H-3.
A good streak virus tolerant composite (TZSR)
from IITA has been included in the B population in
Kenya. Streak-resistant inbred lines for both lowland
and mid-altitude environments have been supplied by


IITA (personal communication, S.K. Kim). Breeding
materials from the CIMMYT/University of Zimbabwe
collaborative mid-altitude breeding program are also
being supplied from Harare.
The Kenya Seed Company (KSC), in which the
Government of Kenya now has 51% ownership, has a
monopoly on seed production in the country and also
exports seed (hybrids) to neighboring countries. Maize
seed constitutes its largest crop, with a volume in 1984
of 14,000 t. In 1985-86, the KSC produced 10 hybrids
and 2 open-pollinated varieties for the various agrocli-
matic areas of the country. Breeder seed for these
varieties comes from three agricultural research sta-
tions and from KSC's small but effective maize re-
search program. Most farmers in the high potential
areas use improved seed. In marginal regions, lan-
draces are still often found.

LESOTHO

Maize is the staple food in Lesotho. In 1983,90,000
t of grain were produced on 60,000 ha, with national
yield averaging 1.5 t/ha.Lesotho is entirely surrounded
by South Africa. Maize growing areas can be divided
into three major agroecological zones: the lowlands,
the foothills, and the Maloti mountain range, where
land is cultivated as high as 3,000 m elevation.
Maize research is carried out by Agricultural Re-
search Lesotho (Ntlhabo and Matli 1985). For the low
elevations, South African hybrids are the dominant
materials grown. In the more mountainous regions,
because of the shorter growing season and cooler
conditions and the subsistence nature of maize produc-
tion, open-pollinated varieties are more suitable geno-
types. CIMMYT is collaborating with Lesotho re-
searchers to develop high-yielding varieties for the
highland areas. Pools 1, 2, and 4 supplied by CIMMYT
markedly outyield the two best South African hybrids,
SA4 and SA1l, in this zone. Seeds from these materials
have been multiplied and are being tested extensively
through on-farm trials. CIMMYT reports that Pools 1
and 4 have been released as open-pollinated varieties
and are under commercial production.

MAIAWI
Maize is the principal staple food in Malawi. Dur-
ing 1983-85, approximately 1.4 million t of grain were
produced annually on 1.2 million ha, with national
yields averaging 1.2 t/ha. In recent years, Malawi has
been a net maize exporter. Maize is grown by small-scale
farmers for food and cash and by large-scale farmers








RECENT RELEASES


Table 2. Maize varieties released by
Kenyan National Breeding Programs

Year of Yield
Variety Typeb release (% of KSM)
KSM OP 100
ECU 573 OP 1959 -
KS II OP 1961 107
H 611 VC 1964 142
H 621 DC 1964 132
H 631 TWC 1964 140
H 622 DC 1965 135
H 632 TWC 1965 140
H 612 TC 1966 155
KCB OP 1967 -
H 511 VC 1967
H 512 VC 1970 -
H 611C VC 1971 155
H 613 TC 1972 166
CMC OP 1974
H 614 TC 1976 166
H625 DC 1981 176

Source: Ochieng 1985
aKCB = Katumaini Composite B; CMC = Coastal
Maize Composite;
bOP = open-pollinatedvariety; VC = variety cross;
DC = double-cross hybrid; TWC = three- way cross
hybrid; TC = top-cross hybrid


not accept anything else. Between 1963 and 1981, the
hybrid area has increased from zero to nearly 600,000
ha. Until the late 1960s, large-scale farmers dominated
the use ofhybrids; since then, the number of small-scale
farmers has increased greatly.
Maize materials from both CIMMYT and IITA
continue to be evaluated by national maize program
scientists. Some have been used for the development of
several experimental hybrids yet to be released. Al-
though CIMMYT populations and pools are generally
susceptible to common rust and turcicum blight, some
are being used in the breeding program. CIMMYT
Populations 21 (Tuxpefio-1), 49 (Blanco Dentado-2),
and 32 (ETO Blanco) have been used in the develop-
ment of several varietal hybrids in Kenya: PWAN-1,
H-1, H-2, and H-3.
A good streak virus tolerant composite (TZSR)
from IITA has been included in the B population in
Kenya. Streak-resistant inbred lines for both lowland
and mid-altitude environments have been supplied by


IITA (personal communication, S.K. Kim). Breeding
materials from the CIMMYT/University of Zimbabwe
collaborative mid-altitude breeding program are also
being supplied from Harare.
The Kenya Seed Company (KSC), in which the
Government of Kenya now has 51% ownership, has a
monopoly on seed production in the country and also
exports seed (hybrids) to neighboring countries. Maize
seed constitutes its largest crop, with a volume in 1984
of 14,000 t. In 1985-86, the KSC produced 10 hybrids
and 2 open-pollinated varieties for the various agrocli-
matic areas of the country. Breeder seed for these
varieties comes from three agricultural research sta-
tions and from KSC's small but effective maize re-
search program. Most farmers in the high potential
areas use improved seed. In marginal regions, lan-
draces are still often found.

LESOTHO

Maize is the staple food in Lesotho. In 1983,90,000
t of grain were produced on 60,000 ha, with national
yield averaging 1.5 t/ha.Lesotho is entirely surrounded
by South Africa. Maize growing areas can be divided
into three major agroecological zones: the lowlands,
the foothills, and the Maloti mountain range, where
land is cultivated as high as 3,000 m elevation.
Maize research is carried out by Agricultural Re-
search Lesotho (Ntlhabo and Matli 1985). For the low
elevations, South African hybrids are the dominant
materials grown. In the more mountainous regions,
because of the shorter growing season and cooler
conditions and the subsistence nature of maize produc-
tion, open-pollinated varieties are more suitable geno-
types. CIMMYT is collaborating with Lesotho re-
searchers to develop high-yielding varieties for the
highland areas. Pools 1, 2, and 4 supplied by CIMMYT
markedly outyield the two best South African hybrids,
SA4 and SA1l, in this zone. Seeds from these materials
have been multiplied and are being tested extensively
through on-farm trials. CIMMYT reports that Pools 1
and 4 have been released as open-pollinated varieties
and are under commercial production.

MAIAWI
Maize is the principal staple food in Malawi. Dur-
ing 1983-85, approximately 1.4 million t of grain were
produced annually on 1.2 million ha, with national
yields averaging 1.2 t/ha. In recent years, Malawi has
been a net maize exporter. Maize is grown by small-scale
farmers for food and cash and by large-scale farmers









IMPROVED MAIZE VARIETIES AND HYBRIDS


Table 3. Seed produced by the National Seed Company of Malawi, 1978-79 to 1983-84, in tons

Material 1978-79 1979-80 1980-81 1981-82 1982-83 1983-84
MH 12 (single
cross) 911 1,143 2,123 1,704 1,617 3,015
MH 13 (3-way
cross) 37 166 -
NSCM 41 (3-way
cross) 9 236 574
UCA Basic
(composite) 6 -
UCA (certified) 201 515 2,231 153 135 333
CCA Basic
(composite) 7 70
CCA Certified 90 35 44 55 110 53
A 73N (inbred line) 42 19 52 57 1
B 76S (inbred line) 8 5 -

Source: National Seed Company of Malawi


mainly for commercial purposes. There has been a
remarkable increase in the area grown with maize over
the past five years, though not in yields.
About one-quarter of the maize area in Malawi is
planted with improved materials: 17% with improved
open-pollinated maize (composites) and 9% with hybrids
(personal communication, A. Manwiller). The local
unimproved varieties are mostly flints to semi-flints,
which are preferred because of their resistance to
stored-grain insect attack and because of their
flour-making qualities. Initially, maize breeders were
using dents in their improvement programs. CIMMYT
has supplied improved flint germplasm, and these
materials are being used in crosses with Malawian
dents. Hybrid maize is grown only for commercial
purposes where industrial millers sell meal mainly to
the urban population.
Maize improvement work in Malawi is focused on
production problems in two ecological zones: (a) high
potential areas where rainfall is not a limiting factor
(more than 600 mm) to successful maize growth and
(b) marginal areas where rainfall (less than 600 mm) is
a limiting factor (Ngwira and Sibale 1985). The pro-
gram for marginal areas is evaluating materials with
earlier maturity from CIMMYT, IITA, and South
Africa. The materials obtained from South Africa are
mainly inbred lines that perform better than materials
from other regions of the world in terms of disease and


adaptability. A number of the newly released hybrids in
Malawi, mostly single-cross hybrids, have been derived
from these lines.
CIMMYT materials-especially white flints-have
served the national program in two ways: (a) for direct
or indirect use in the formation of open-pollinated
varieties for the small-scale farmer and (b) to form new
source populations. An open-pollinated variety, Chit-
edze composite C, was released in 1976. This compos-
ite was formed by crossing 36 entries selected on the
basis of their visual performance in two CIMMYT
variety trials, EVT 12 and ELVT 18, consisting mostly
of late tropical materials of variable kernel types.
Tuxpefio 1 (Pop. 21) was also identified from the
CIMMYT experimental varieties as being well adapted
to the northern lakeshore area of Malawi. This variety
was released in 1985 under the same name.
Since 1981, the Malawi Improvement Program has
been cooperating with IITA. It has received streak-
resistant materials that have been incorporated into
national breeding populations for evaluation under
local conditions of natural infection. Inbred lines are
being extracted from one population, TZESR, which is
moderately resistant to streak virus attack. IITA inbred
lines and hybrids have also been supplied to maize
researchers at the Chitedze Station (personal commu-
nication, S.K. Kim).









RECENT RELEASES


The National Seed Company of Malawi (NSCM),
established in 1976, multiplies the seed of improved
materials by contract with commercial farmers. Seed
of both hybrids and open-pollinated varieties has been
produced (table 3).
At present, NSCM is handling two hybrids: MH12,
a single-cross hybrid, and NSCM 41, a three-way cross
hybrid. Parent seed for two newly released hybrids was
handed over to the company in 1984, and production of
the new hybrids was planned to commence in the 1985-
86 cropping season. NSCM also produces seed of
composite varieties. At present, it is producing Ukirigula
Composite A (UCA) and Chitedze Composite A (CCA).
Tuxpefio 1 will shortly be added to the list of
open-pollinated maize seed multiplied by the com-
pany.

MOZAMBIQUE
Maize is the main staple food of most Mozambi-
cans and is grown throughout the country. During
1983-85,333,000 t of grain were produced annually on
600,000 ha, with national yields-the lowest in
sub-SaharanAfrica-averaging 0.6 t/ha. Disease prob-
lems (mainly downy mildew and maize streak virus),
insect pests, weeds, and lack of water are all serious
biological constraints in one or more of the three major
agroecological zones in which maize is grown.
Maize research is carried out by the National
Agricultural Research Institute (INIA), which initi-
ated the national maize research program after inde-
pendence in 1977 (Nunes and Sataric 1985). In recent
years, social and political upheavals have seriously
affected maize research efforts, and many valuable
materials have been lost.
Several open-pollinated varieties based on CIM-
MYT materials have been selected for release. Foun-
dation seed has been produced for five experimental
varieties: Obregon 7643, Cotaxla 7921, and Ferke 7822
for high altitudes; and San Andres 7823 and Mexico
8049 for the northern lowlands. Streak resistant mate-
rials from IITA have also been obtained and are being
used in the breeding program; a variety based on
TZESR-W has been selected for commercial release
(personal communication, S.K. Kim). Through techni-
cal assistance from the Yugoslavian Maize Institute, a
hybrid development program was started in 1984.
Three national institutions are involved in maize
seed production: INIA is responsible for producing
breeders' and basic seed; the National Seed Company
(ENS) is responsible for certified seed production; and
the National Seed Service (SNC) is charged with qual-
ity control.


REUNION
The Department Cultures Vivrieres Du Cirad
cooperates with IITA and CIMMYT in germplasm
exchange and testing (Marchand and Hainzelin 1985).
The breeding program is devoting major efforts to the
study of four viruses: maize streak virus, maize mosaic
virus, maize stripe virus, and sugar cane mosaic virus.
Since vector insects are important in virus transmission
in maize the entomological aspects of these diseases
are also under study. IITA's streak-resistant materials
are also being utilized. IITA's inbred lines are also used
to test strain variations of maize streak virus (personal
communication, S.K. Kim). Tocumen (1) 7931, se-
lected from CIMMYT material in 1984, is being in-
creased despite susceptibility to H. turcicum. Most
farmers grow open-pollinated varieties, but one hy-
brid, IRAT 143, has had some success.
Seed production in Reunion is very limited and not
well organized. Scattered private institutions produce
seed but there is no organized agency. In 1985, im-
proved seed of the following genotypes was produced
(Marchand and Hainzelin 1985): Revolution (local
improved variety), 5 t; IRAT 143 (hybrid), 1 t; and
Tocumen (1) 7931, 5 t.

SOUTH AFRICA
Maize is the major staple for most of the country's
people. During 1983-85, approximately 5.3 million t of
grain were produced on 4.1 million ha, with national
yields averaging 1.3 t/ha. During 1982 and 1983, severe
drought reduced national production: viz, 13 million t
in 1980 and 4 million t in 1982. In most years, however,
South Africa is an important maize exporter.
Almost all of the South African maize area is
planted with hybrids-three-way and four-way crosses
(personal communication, Mike Barrow). Most of
these hybrids are based on material from the United
States that was introduced during the early part of this
century (personal communication, D. Duvick). There
are no public sector seed companies handling maize
seed. Seven private companies are active in South
Africa. Materials from CIMMYT and IITA have not
been well adapted, but they are screened for disease
resistance and for resistance/tolerance to African Maize
Stalk borer, Busseolafusca. The Pioneer Seed Com-
pany (Pty) Limited (no association with Pioneer Hi-Bred
International Co. of the United States) has received
open-pollinated populations from both IITA and
CIMMYT. Inbred lines are being developed from the
most promising materials (80% to 85% of effort), and
population improvement makes up the remainder of
the breeding program.









RECENT RELEASES


The National Seed Company of Malawi (NSCM),
established in 1976, multiplies the seed of improved
materials by contract with commercial farmers. Seed
of both hybrids and open-pollinated varieties has been
produced (table 3).
At present, NSCM is handling two hybrids: MH12,
a single-cross hybrid, and NSCM 41, a three-way cross
hybrid. Parent seed for two newly released hybrids was
handed over to the company in 1984, and production of
the new hybrids was planned to commence in the 1985-
86 cropping season. NSCM also produces seed of
composite varieties. At present, it is producing Ukirigula
Composite A (UCA) and Chitedze Composite A (CCA).
Tuxpefio 1 will shortly be added to the list of
open-pollinated maize seed multiplied by the com-
pany.

MOZAMBIQUE
Maize is the main staple food of most Mozambi-
cans and is grown throughout the country. During
1983-85,333,000 t of grain were produced annually on
600,000 ha, with national yields-the lowest in
sub-SaharanAfrica-averaging 0.6 t/ha. Disease prob-
lems (mainly downy mildew and maize streak virus),
insect pests, weeds, and lack of water are all serious
biological constraints in one or more of the three major
agroecological zones in which maize is grown.
Maize research is carried out by the National
Agricultural Research Institute (INIA), which initi-
ated the national maize research program after inde-
pendence in 1977 (Nunes and Sataric 1985). In recent
years, social and political upheavals have seriously
affected maize research efforts, and many valuable
materials have been lost.
Several open-pollinated varieties based on CIM-
MYT materials have been selected for release. Foun-
dation seed has been produced for five experimental
varieties: Obregon 7643, Cotaxla 7921, and Ferke 7822
for high altitudes; and San Andres 7823 and Mexico
8049 for the northern lowlands. Streak resistant mate-
rials from IITA have also been obtained and are being
used in the breeding program; a variety based on
TZESR-W has been selected for commercial release
(personal communication, S.K. Kim). Through techni-
cal assistance from the Yugoslavian Maize Institute, a
hybrid development program was started in 1984.
Three national institutions are involved in maize
seed production: INIA is responsible for producing
breeders' and basic seed; the National Seed Company
(ENS) is responsible for certified seed production; and
the National Seed Service (SNC) is charged with qual-
ity control.


REUNION
The Department Cultures Vivrieres Du Cirad
cooperates with IITA and CIMMYT in germplasm
exchange and testing (Marchand and Hainzelin 1985).
The breeding program is devoting major efforts to the
study of four viruses: maize streak virus, maize mosaic
virus, maize stripe virus, and sugar cane mosaic virus.
Since vector insects are important in virus transmission
in maize the entomological aspects of these diseases
are also under study. IITA's streak-resistant materials
are also being utilized. IITA's inbred lines are also used
to test strain variations of maize streak virus (personal
communication, S.K. Kim). Tocumen (1) 7931, se-
lected from CIMMYT material in 1984, is being in-
creased despite susceptibility to H. turcicum. Most
farmers grow open-pollinated varieties, but one hy-
brid, IRAT 143, has had some success.
Seed production in Reunion is very limited and not
well organized. Scattered private institutions produce
seed but there is no organized agency. In 1985, im-
proved seed of the following genotypes was produced
(Marchand and Hainzelin 1985): Revolution (local
improved variety), 5 t; IRAT 143 (hybrid), 1 t; and
Tocumen (1) 7931, 5 t.

SOUTH AFRICA
Maize is the major staple for most of the country's
people. During 1983-85, approximately 5.3 million t of
grain were produced on 4.1 million ha, with national
yields averaging 1.3 t/ha. During 1982 and 1983, severe
drought reduced national production: viz, 13 million t
in 1980 and 4 million t in 1982. In most years, however,
South Africa is an important maize exporter.
Almost all of the South African maize area is
planted with hybrids-three-way and four-way crosses
(personal communication, Mike Barrow). Most of
these hybrids are based on material from the United
States that was introduced during the early part of this
century (personal communication, D. Duvick). There
are no public sector seed companies handling maize
seed. Seven private companies are active in South
Africa. Materials from CIMMYT and IITA have not
been well adapted, but they are screened for disease
resistance and for resistance/tolerance to African Maize
Stalk borer, Busseolafusca. The Pioneer Seed Com-
pany (Pty) Limited (no association with Pioneer Hi-Bred
International Co. of the United States) has received
open-pollinated populations from both IITA and
CIMMYT. Inbred lines are being developed from the
most promising materials (80% to 85% of effort), and
population improvement makes up the remainder of
the breeding program.









RECENT RELEASES


The National Seed Company of Malawi (NSCM),
established in 1976, multiplies the seed of improved
materials by contract with commercial farmers. Seed
of both hybrids and open-pollinated varieties has been
produced (table 3).
At present, NSCM is handling two hybrids: MH12,
a single-cross hybrid, and NSCM 41, a three-way cross
hybrid. Parent seed for two newly released hybrids was
handed over to the company in 1984, and production of
the new hybrids was planned to commence in the 1985-
86 cropping season. NSCM also produces seed of
composite varieties. At present, it is producing Ukirigula
Composite A (UCA) and Chitedze Composite A (CCA).
Tuxpefio 1 will shortly be added to the list of
open-pollinated maize seed multiplied by the com-
pany.

MOZAMBIQUE
Maize is the main staple food of most Mozambi-
cans and is grown throughout the country. During
1983-85,333,000 t of grain were produced annually on
600,000 ha, with national yields-the lowest in
sub-SaharanAfrica-averaging 0.6 t/ha. Disease prob-
lems (mainly downy mildew and maize streak virus),
insect pests, weeds, and lack of water are all serious
biological constraints in one or more of the three major
agroecological zones in which maize is grown.
Maize research is carried out by the National
Agricultural Research Institute (INIA), which initi-
ated the national maize research program after inde-
pendence in 1977 (Nunes and Sataric 1985). In recent
years, social and political upheavals have seriously
affected maize research efforts, and many valuable
materials have been lost.
Several open-pollinated varieties based on CIM-
MYT materials have been selected for release. Foun-
dation seed has been produced for five experimental
varieties: Obregon 7643, Cotaxla 7921, and Ferke 7822
for high altitudes; and San Andres 7823 and Mexico
8049 for the northern lowlands. Streak resistant mate-
rials from IITA have also been obtained and are being
used in the breeding program; a variety based on
TZESR-W has been selected for commercial release
(personal communication, S.K. Kim). Through techni-
cal assistance from the Yugoslavian Maize Institute, a
hybrid development program was started in 1984.
Three national institutions are involved in maize
seed production: INIA is responsible for producing
breeders' and basic seed; the National Seed Company
(ENS) is responsible for certified seed production; and
the National Seed Service (SNC) is charged with qual-
ity control.


REUNION
The Department Cultures Vivrieres Du Cirad
cooperates with IITA and CIMMYT in germplasm
exchange and testing (Marchand and Hainzelin 1985).
The breeding program is devoting major efforts to the
study of four viruses: maize streak virus, maize mosaic
virus, maize stripe virus, and sugar cane mosaic virus.
Since vector insects are important in virus transmission
in maize the entomological aspects of these diseases
are also under study. IITA's streak-resistant materials
are also being utilized. IITA's inbred lines are also used
to test strain variations of maize streak virus (personal
communication, S.K. Kim). Tocumen (1) 7931, se-
lected from CIMMYT material in 1984, is being in-
creased despite susceptibility to H. turcicum. Most
farmers grow open-pollinated varieties, but one hy-
brid, IRAT 143, has had some success.
Seed production in Reunion is very limited and not
well organized. Scattered private institutions produce
seed but there is no organized agency. In 1985, im-
proved seed of the following genotypes was produced
(Marchand and Hainzelin 1985): Revolution (local
improved variety), 5 t; IRAT 143 (hybrid), 1 t; and
Tocumen (1) 7931, 5 t.

SOUTH AFRICA
Maize is the major staple for most of the country's
people. During 1983-85, approximately 5.3 million t of
grain were produced on 4.1 million ha, with national
yields averaging 1.3 t/ha. During 1982 and 1983, severe
drought reduced national production: viz, 13 million t
in 1980 and 4 million t in 1982. In most years, however,
South Africa is an important maize exporter.
Almost all of the South African maize area is
planted with hybrids-three-way and four-way crosses
(personal communication, Mike Barrow). Most of
these hybrids are based on material from the United
States that was introduced during the early part of this
century (personal communication, D. Duvick). There
are no public sector seed companies handling maize
seed. Seven private companies are active in South
Africa. Materials from CIMMYT and IITA have not
been well adapted, but they are screened for disease
resistance and for resistance/tolerance to African Maize
Stalk borer, Busseolafusca. The Pioneer Seed Com-
pany (Pty) Limited (no association with Pioneer Hi-Bred
International Co. of the United States) has received
open-pollinated populations from both IITA and
CIMMYT. Inbred lines are being developed from the
most promising materials (80% to 85% of effort), and
population improvement makes up the remainder of
the breeding program.









IMPROVED MAIZE VARIETIES AND HYBRIDS


Figure 8. CIMMYT maize trainee from Africa.
Source: CIMMYT.


SOMALIA
Maize is the second most important crop in Somalia,
after sorghum. During 1983-85, approximately 130,000
t of grain were produced annually on 138,000 ha, with
national yields averaging 0.9 t/ha.
Maize research began in 1977 and is carried out by
the Central Agricultural Research Station (CARS) at
Afgoi (Abbanur 1985). In 1979, the variety Afgoi
Composite was developed from Somali landraces,
Guatemala Flint, and U.S. hybrids. Another variety,
Somtux, was developed in 1980 from half-sib crosses
between Afgoi Composite and Tuxpefio (obtained
from Tanzania). Somtux is a white, semi-dent grain,
full-season variety. Because of discontinuity in the
breeding programs, both varieties have lost their ge-
netic purity and have become contaminated.
The Somali maize program's germplasm improve-
ment priorities are to develop high-yielding varieties
with tolerance to drought and resistance to the stem


borer Chilopartellus. CIMMYT, IITA, and the Semi-
Arid Food Grains Research and Development project
(SAFGRAD) are cooperating with CARS in these
breeding efforts. Nearly 200 experimental varieties
supplied by CIMMYT have been evaluated in field
trials since 1981. Promising materials include Across
8121, Across 8149, Los Diamantes 7823, Across 7822,
Pirsabak 7930 (early maturing) and Poza Rica 7926.
The best performing materials from the SAFGRAD
trials have been Pool 16 (early maturing) and TZPB.
Pirsabak 7930 and Pool 16 are being crossed with the
F1 progeny of the locally developed variety-cross hy-
brid, ISOMA, in order to introduce greater earliness
into this material.

SWAZILAND
Maize is the principal staple in Swaziland. Approxi-
mately 90,000 t of grain were produced annually in
1983-85 on 60,000 ha, with national yields averaging 1.5
t/ha. Maize production has been cyclic depending on
climatic conditions in recent years.
Approximately 80% of the land is planted with
hybrids, with the balance planted with local
open-pollinated materials or second-generation hy-
brid seed (Shikhulu and Mavimbela 1985). The main
hybrids in use are SR 52 (from Zimbabwe) and NPP x
K64R (from South Africa). Seed of hybrid maize is
produced and distributed by a national agency, the
Swaziland Seed Multiplication Project. Several private
companies and cooperatives also distribute maize seed.
Inbred lines and varieties with maize streak virus
resistance are received from IITA. The program also
receives open-pollinated varieties from CIMMYT that
are evaluated for yield and general adaptation. One
such variety, Across 7443, is now commercially avail-
able. Several more varieties-based on CIMMYT
Populations 22 (Mezcla Tropical Blanca), 23 (Blanco
Cristalino-1), 24 (Antigua-Veracruz 181), and 47
(Templado Blanco Dentado-2)-have been selected
for further testing and possible eventual release.

TANZANIA
Maize is the most important food crop in Tanzania.
In 1983-85, approximately 1.6 million t of grain were
produced annually on 1.5 million ha, with national
yields averaging 1.1 t/ha. Most farmers prefer white,
flint-type maizes.
Tanzania's National Maize Research Program
(NMRP) was established in 1973 with the assistance of
IITA, CIMMYT, and USAID. Maize research is fo-









RECENT RELEASES


caused on three agroecological zones (personal com-
munication, AJ. Moshi): (1) the lowland zone, includ-
ing coastal and other areas below 900 m elevation, (2)
a mid-altitude zone between 900 and 1,500 m but
subdivided into two sub-zones: (a) areas with more
than 1,100 mm rainfall and with a longer growing
season, and (b) areas with less than 1,100 mm rainfall
and with a shorter growing season, and (3) the highland
zone above 1,500 m elevation-the major production
area-which usually receives sufficient rainfall and has
relatively long growing seasons. Maize streak virus is a
problem in the lowland and mid-altitude zones, and H.
turcicum, ear rot, and stalk borers can be serious
problems in the high-altitude zones.
The breeding program has been involved in im-
proving populations, in the formation and testing of
varieties, and in the supplying of national foundation
seed farms with breeders' seed of both open-pollinated
varieties and inbred lines. A major effort is aimed at
formation of open-pollinated varieties for commercial
use by farmers. About 10% of the breeding program
involves inbred development and hybrids, but this
activity is increasing. Beginning in the 1982-83 season,
the NMRP began forming top crosses for possible
hybrid production and for obtaining information for
restructuring the populations on the basis of heterotic
patterns.
The NMRP of Tanzania cooperates with various
international breeding programs including CIMMYT,
IITA, and SAFGRAD (personal communication, AJ.
Moshi). International progeny trials are tested for local
adaptation; variety trials are received for both
open-pollinated and hybrid materials; and seed is re-
quested of varieties, inbreds, and breeding material.
The materials are either tested locally or used in
breeding and selection for local improvement. Four
open-pollinated varieties based on CIMMYT germplasm
have been released for commercial production. Mate-
rials from IITA are evaluated for streak virus diseases
resistance. TZESR-W has shown high resistance to
MSV and good yield potential in national trials (per-
sonal communication, S.K. Kim). None of the IITA
material has been released, but some of the streak
resistant converted materials and newly tested hybrids
are promising.
Presently, two hybrids, H 6302 and H 614, devel-
oped by the East African Agriculture and Forestry
Research Organization (EAAFRO), are recommended
for the high-elevation, long-season areas of the south-
ern highlands. The hybrids, H 632 and H 622, and the
open-pollinated variety, UCA, are recommended for


Table 4. Seed production of improved
maize genotypes in Tanzania, 1972-73 to
1983-84, in tons

Open-
pollinated
Season Hybrids varieties Total
1972-73 420 1 421
1973-74 666 109 775
1974-75 1,366 1,050 2,416
1975-76 1,484 1,638 3,122
1976-77 916 2,128 3,044
1977-78 409 1,061 1,470
1978-79 2,485 1,615 4,100
1979-80 3,022 107 3,129
1980-81 2,129 1,516 3,645
1981-82 1,525 851 2,376
1982-83 1,909 1,465 3,374
1983-84 2,537 1,114 3,651
Source: Personal communication, A.J. Moshi.



the intermediate-elevation areas. For several years,
Illonga Composite has been recommended for areas
below 900 m elevation. The full-season variety, Tuxpeiio
(Population 21, Tuxpefio-1) is grown on a limited scale
in the northeastern and southern lowlands. Until re-
cently the variety Katumani was the only early-maturing
material available. In 1983, the NMRP released a new
early-maturing variety, Kito (Population 30, Blanco
Cristalino-2), for areas below 1,300 m elevation and
two full-season varieties, Kilima (Pop. 21) and Staha
(Pop. 21), for the intermediate and low-altitude zones,
respectively.
Improved variety and hybrid breeder's seed is in-
creased to foundation seed at national foundation seed
farms. The Tanzania Seed Company, established in
1973, contracts with institutions and larger scale farm-
ers to produce certified seed. The latter is marketed
solely by the Tanzania Seed Company. There is no
private maize seed company. The use of improved seed
has increased significantly since 1973 (table 4). Even
so, many farmers still do not buy certified seed because
of cost factors, delivery problems, and a lack of knowl-
edge about the importance of using quality seed.









IMPROVED MAIZE VARIETIES AND HYBRIDS


Figure 8. CIMMYT maize trainee from Africa.
Source: CIMMYT.


SOMALIA
Maize is the second most important crop in Somalia,
after sorghum. During 1983-85, approximately 130,000
t of grain were produced annually on 138,000 ha, with
national yields averaging 0.9 t/ha.
Maize research began in 1977 and is carried out by
the Central Agricultural Research Station (CARS) at
Afgoi (Abbanur 1985). In 1979, the variety Afgoi
Composite was developed from Somali landraces,
Guatemala Flint, and U.S. hybrids. Another variety,
Somtux, was developed in 1980 from half-sib crosses
between Afgoi Composite and Tuxpefio (obtained
from Tanzania). Somtux is a white, semi-dent grain,
full-season variety. Because of discontinuity in the
breeding programs, both varieties have lost their ge-
netic purity and have become contaminated.
The Somali maize program's germplasm improve-
ment priorities are to develop high-yielding varieties
with tolerance to drought and resistance to the stem


borer Chilopartellus. CIMMYT, IITA, and the Semi-
Arid Food Grains Research and Development project
(SAFGRAD) are cooperating with CARS in these
breeding efforts. Nearly 200 experimental varieties
supplied by CIMMYT have been evaluated in field
trials since 1981. Promising materials include Across
8121, Across 8149, Los Diamantes 7823, Across 7822,
Pirsabak 7930 (early maturing) and Poza Rica 7926.
The best performing materials from the SAFGRAD
trials have been Pool 16 (early maturing) and TZPB.
Pirsabak 7930 and Pool 16 are being crossed with the
F1 progeny of the locally developed variety-cross hy-
brid, ISOMA, in order to introduce greater earliness
into this material.

SWAZILAND
Maize is the principal staple in Swaziland. Approxi-
mately 90,000 t of grain were produced annually in
1983-85 on 60,000 ha, with national yields averaging 1.5
t/ha. Maize production has been cyclic depending on
climatic conditions in recent years.
Approximately 80% of the land is planted with
hybrids, with the balance planted with local
open-pollinated materials or second-generation hy-
brid seed (Shikhulu and Mavimbela 1985). The main
hybrids in use are SR 52 (from Zimbabwe) and NPP x
K64R (from South Africa). Seed of hybrid maize is
produced and distributed by a national agency, the
Swaziland Seed Multiplication Project. Several private
companies and cooperatives also distribute maize seed.
Inbred lines and varieties with maize streak virus
resistance are received from IITA. The program also
receives open-pollinated varieties from CIMMYT that
are evaluated for yield and general adaptation. One
such variety, Across 7443, is now commercially avail-
able. Several more varieties-based on CIMMYT
Populations 22 (Mezcla Tropical Blanca), 23 (Blanco
Cristalino-1), 24 (Antigua-Veracruz 181), and 47
(Templado Blanco Dentado-2)-have been selected
for further testing and possible eventual release.

TANZANIA
Maize is the most important food crop in Tanzania.
In 1983-85, approximately 1.6 million t of grain were
produced annually on 1.5 million ha, with national
yields averaging 1.1 t/ha. Most farmers prefer white,
flint-type maizes.
Tanzania's National Maize Research Program
(NMRP) was established in 1973 with the assistance of
IITA, CIMMYT, and USAID. Maize research is fo-









IMPROVED MAIZE VARIETIES AND HYBRIDS


Figure 8. CIMMYT maize trainee from Africa.
Source: CIMMYT.


SOMALIA
Maize is the second most important crop in Somalia,
after sorghum. During 1983-85, approximately 130,000
t of grain were produced annually on 138,000 ha, with
national yields averaging 0.9 t/ha.
Maize research began in 1977 and is carried out by
the Central Agricultural Research Station (CARS) at
Afgoi (Abbanur 1985). In 1979, the variety Afgoi
Composite was developed from Somali landraces,
Guatemala Flint, and U.S. hybrids. Another variety,
Somtux, was developed in 1980 from half-sib crosses
between Afgoi Composite and Tuxpefio (obtained
from Tanzania). Somtux is a white, semi-dent grain,
full-season variety. Because of discontinuity in the
breeding programs, both varieties have lost their ge-
netic purity and have become contaminated.
The Somali maize program's germplasm improve-
ment priorities are to develop high-yielding varieties
with tolerance to drought and resistance to the stem


borer Chilopartellus. CIMMYT, IITA, and the Semi-
Arid Food Grains Research and Development project
(SAFGRAD) are cooperating with CARS in these
breeding efforts. Nearly 200 experimental varieties
supplied by CIMMYT have been evaluated in field
trials since 1981. Promising materials include Across
8121, Across 8149, Los Diamantes 7823, Across 7822,
Pirsabak 7930 (early maturing) and Poza Rica 7926.
The best performing materials from the SAFGRAD
trials have been Pool 16 (early maturing) and TZPB.
Pirsabak 7930 and Pool 16 are being crossed with the
F1 progeny of the locally developed variety-cross hy-
brid, ISOMA, in order to introduce greater earliness
into this material.

SWAZILAND
Maize is the principal staple in Swaziland. Approxi-
mately 90,000 t of grain were produced annually in
1983-85 on 60,000 ha, with national yields averaging 1.5
t/ha. Maize production has been cyclic depending on
climatic conditions in recent years.
Approximately 80% of the land is planted with
hybrids, with the balance planted with local
open-pollinated materials or second-generation hy-
brid seed (Shikhulu and Mavimbela 1985). The main
hybrids in use are SR 52 (from Zimbabwe) and NPP x
K64R (from South Africa). Seed of hybrid maize is
produced and distributed by a national agency, the
Swaziland Seed Multiplication Project. Several private
companies and cooperatives also distribute maize seed.
Inbred lines and varieties with maize streak virus
resistance are received from IITA. The program also
receives open-pollinated varieties from CIMMYT that
are evaluated for yield and general adaptation. One
such variety, Across 7443, is now commercially avail-
able. Several more varieties-based on CIMMYT
Populations 22 (Mezcla Tropical Blanca), 23 (Blanco
Cristalino-1), 24 (Antigua-Veracruz 181), and 47
(Templado Blanco Dentado-2)-have been selected
for further testing and possible eventual release.

TANZANIA
Maize is the most important food crop in Tanzania.
In 1983-85, approximately 1.6 million t of grain were
produced annually on 1.5 million ha, with national
yields averaging 1.1 t/ha. Most farmers prefer white,
flint-type maizes.
Tanzania's National Maize Research Program
(NMRP) was established in 1973 with the assistance of
IITA, CIMMYT, and USAID. Maize research is fo-









IMPROVED MAIZE VARIETIES AND HYBRIDS


UGANDA
Maize is an important staple in Uganda. During
1983-85, approximately 365,000 t of grain were pro-
duced annually on 358,000 ha, with national yields
averaging 1.2 t/ha.
The Ugandan maize program has been destroyed
by internal war and must be rebuilt. Cooperation with
IITA and CIMMYT will be very important in supplying
populations and inbred lines (personal communica-
tion, Oguti W. Mangheni). IITA has supplied
streak-resistant material for the lowland areas and has
been assisting in converting local varieties to streak
resistance. The Ugandan maize program is also inter-
ested in releasing varieties from CIMMYT Popula-
tions 21 (Tuxpeiio-1), 22 (Mezcla Tropical Blanca, 43
(La Posta), and 49 (Blanco Dentado-2) (Kaahwa and
Kabeere 1985).
The most popular improved open-pollinated varie-
ties in Uganda are Kawanda Composite A and Katu-
mani, a Kenyan variety used in the semi-arid Karamoja
region. Some hybrid seed is also imported from Kenya,
mainly H 622, H 632, and H 614. The Uganda Seed
Project (USP) is responsible for the production of
improved seed, which is marketed by farmers' coop-
eratives as well as by the USP. The Karamoja Seed
Scheme also produces improved seed for farmers in
that region.

ZAMBIA
Maize is the most important crop in Zambia. It is
grown in most regions of the country, except in excep-
tionally dry, wet, or infertile areas where sorghum,
millet, or cassava are better adapted. During 1983-85,
approximately 863,000 t of grain were produced annu-
ally on 512,000 ha, with national yields averaging 1.7 t/
ha, among the highest in sub-Saharan Africa.
Hybrids dominate commercial production areas,
and open-pollinated varieties dominate subsistence
agriculture areas. Approximately 30% of the total
maize area is planted with hybrids and 15% with
improved open-pollinated varieties and composites
(Chibasa 1985). Maize streak virus can cause serious
economic losses in certain years (personal communi-
cation, S.K. Kim).
CIMMYT and IITA collaborate with Zambian
maize researchers, and international trials from both
IARCs are regularly received and grown. Two
open-pollinated varieties based on CIMMYT germplasm
have been released by the national program. Since
1980, scientists in a joint Zambia/FAO research proj-


ect have screened over 200 streak-resistant lines in a
national hybrid development program. A collaborative
Zambian/Yugoslavian maize program has also used
IITA lines for hybrid development IITA's streak-resistant
mid-altitude population (TZMSR-W) and several of
the CIMMYT/IITA streak-resistant conversions of
experimental varieties show promise in Zambia (per-
sonal communication, S.K. Kim).
The Zambia Seed Company (Zamseed) has been
responsible for the production, procurement, and dis-
tribution of maize seed. The seed is produced by
farmers in the Zambian Seed Producers Association,
and quality control is conducted by the Seed Control
and Certification Institute. The main hybrid in use is
SR 52 (single-cross) which was developed in Zim-
babwe. In 1983, an improved version of SR 52, named
MM 752, was released and has shown great promise. In
1984, seven other hybrids were released: MM 501, MM
504, MM 602, MM 603, MM 604, and MM 606. In
addition, two open-pollinated varieties based on
CIMMYT materials, MMV 400 (Pirsabak (2) 7930,
Pop. 30, Blanco Cristalino-1) and MMV 600 (Pop. 21,
Tuxpefio-1), were also released and are being exten-
sively grown. These new cultivars provide Zambian
maize producers with the needed flexibility to adjust
planting dates according to the onset and duration of
the rainy season (Chibasa 1985).

ZIMBABWE
Maize is the principal staple in Zimbabwe. During
1983-85, approximately 1.7 million t of grain were
produced annually on 1.3 million ha, with national
yields averaging 1.2 t/ha. Both total production and
yields during this 2-year period were 25% below aver-
age due to severe drought. In most years, Zimbabwe is
a net maize exporter.
Zimbabwe's maize breeding program was started
in 1932 and is one of the oldest in Africa. The initial
genotypes developed were open-pollinated varieties.
In 1950, Southern Cross was the dominant variety
grown in the country. Since then, 14 double, 5 three-way,
6 single, and 6 modified single-cross hybrids have been
released (personal communication, R.C. Olver). The
single-cross hybrid, SR 52, released in 1960, replaced
SR 14 because it was higher yielding. For more than
two decades, SR 52 has continued to be the dominant
hybrid in Zimbabwe (grown on 85% of hybrid area)
and is also widely grown in other African countries
(Billing 1985). Two shorter season hybrids, R 200 and
R 201, are grown on the remaining 15% of the hybrid
maize area. R 201 has tended to replace R 200, which
is susceptible to weevil damage (Billing 1985).








RECENT RELEASES


Figure 9. Pounding maize to make corn meal for home use, Africa. Source: CIMMYT.


The Zimbabwe maize breeding program cooper-
ates with IITA and CIMMYT. This collaboration was
strengthened substantially with the establishment of a
joint mid-altitude breeding station in cooperation with
the University of Zimbabwe. The station was estab-
lished jointly by CIMMYT and IITA in 1985 and
operated for 2 years under joint sponsorship. IITA has
recently withdrawn from formal involvement as part of
a new agreement with CIMMYT concerning regional
division of responsibility (IITA for western and central
Africa, and CIMMYT for eastern and southern Af-
rica). But ITA will continue to be informally involved
and cooperate with CIMMYT.
The greatest contribution from the IARCs has
been the identification of streak virus resistant germplasm
and the incorporation of this into different local popu-
lations. ITA's mid-altitude population, TZMSR-W-and
the inbreds and hybrids derived from it-have shown


high resistance to MSV and H. turcicum (personal
communication, S.K. Kim). CIMMYT's international
progeny and variety trials are routinely evaluated;
Population 48 is also being used to reduce plant height
in various national materials. Relatively small propor-
tions of CIMMYT and IITA germplasm have been
introgressed into a few of the 28 locally constituted
populations, which are undergoing various forms of
recurrent selection to serve as long-term genetic sources
of new inbred lines. None of the released hybrids have
any germplasm from either CIMMYT or IITA.
The Seed Co-op Company of Zimbabwe, a coop-
erative of commercial farmers, has the sole right to
market government-developed hybrids. All commer-
cial farmers grow hybrids and at least 70% of the
communal peasant farmers also grow hybrids (Billing
1985). The commercial farmers grow about 250,000 ha









IMPROVED MAIZE VARIETIES AND HYBRIDS


UGANDA
Maize is an important staple in Uganda. During
1983-85, approximately 365,000 t of grain were pro-
duced annually on 358,000 ha, with national yields
averaging 1.2 t/ha.
The Ugandan maize program has been destroyed
by internal war and must be rebuilt. Cooperation with
IITA and CIMMYT will be very important in supplying
populations and inbred lines (personal communica-
tion, Oguti W. Mangheni). IITA has supplied
streak-resistant material for the lowland areas and has
been assisting in converting local varieties to streak
resistance. The Ugandan maize program is also inter-
ested in releasing varieties from CIMMYT Popula-
tions 21 (Tuxpeiio-1), 22 (Mezcla Tropical Blanca, 43
(La Posta), and 49 (Blanco Dentado-2) (Kaahwa and
Kabeere 1985).
The most popular improved open-pollinated varie-
ties in Uganda are Kawanda Composite A and Katu-
mani, a Kenyan variety used in the semi-arid Karamoja
region. Some hybrid seed is also imported from Kenya,
mainly H 622, H 632, and H 614. The Uganda Seed
Project (USP) is responsible for the production of
improved seed, which is marketed by farmers' coop-
eratives as well as by the USP. The Karamoja Seed
Scheme also produces improved seed for farmers in
that region.

ZAMBIA
Maize is the most important crop in Zambia. It is
grown in most regions of the country, except in excep-
tionally dry, wet, or infertile areas where sorghum,
millet, or cassava are better adapted. During 1983-85,
approximately 863,000 t of grain were produced annu-
ally on 512,000 ha, with national yields averaging 1.7 t/
ha, among the highest in sub-Saharan Africa.
Hybrids dominate commercial production areas,
and open-pollinated varieties dominate subsistence
agriculture areas. Approximately 30% of the total
maize area is planted with hybrids and 15% with
improved open-pollinated varieties and composites
(Chibasa 1985). Maize streak virus can cause serious
economic losses in certain years (personal communi-
cation, S.K. Kim).
CIMMYT and IITA collaborate with Zambian
maize researchers, and international trials from both
IARCs are regularly received and grown. Two
open-pollinated varieties based on CIMMYT germplasm
have been released by the national program. Since
1980, scientists in a joint Zambia/FAO research proj-


ect have screened over 200 streak-resistant lines in a
national hybrid development program. A collaborative
Zambian/Yugoslavian maize program has also used
IITA lines for hybrid development IITA's streak-resistant
mid-altitude population (TZMSR-W) and several of
the CIMMYT/IITA streak-resistant conversions of
experimental varieties show promise in Zambia (per-
sonal communication, S.K. Kim).
The Zambia Seed Company (Zamseed) has been
responsible for the production, procurement, and dis-
tribution of maize seed. The seed is produced by
farmers in the Zambian Seed Producers Association,
and quality control is conducted by the Seed Control
and Certification Institute. The main hybrid in use is
SR 52 (single-cross) which was developed in Zim-
babwe. In 1983, an improved version of SR 52, named
MM 752, was released and has shown great promise. In
1984, seven other hybrids were released: MM 501, MM
504, MM 602, MM 603, MM 604, and MM 606. In
addition, two open-pollinated varieties based on
CIMMYT materials, MMV 400 (Pirsabak (2) 7930,
Pop. 30, Blanco Cristalino-1) and MMV 600 (Pop. 21,
Tuxpefio-1), were also released and are being exten-
sively grown. These new cultivars provide Zambian
maize producers with the needed flexibility to adjust
planting dates according to the onset and duration of
the rainy season (Chibasa 1985).

ZIMBABWE
Maize is the principal staple in Zimbabwe. During
1983-85, approximately 1.7 million t of grain were
produced annually on 1.3 million ha, with national
yields averaging 1.2 t/ha. Both total production and
yields during this 2-year period were 25% below aver-
age due to severe drought. In most years, Zimbabwe is
a net maize exporter.
Zimbabwe's maize breeding program was started
in 1932 and is one of the oldest in Africa. The initial
genotypes developed were open-pollinated varieties.
In 1950, Southern Cross was the dominant variety
grown in the country. Since then, 14 double, 5 three-way,
6 single, and 6 modified single-cross hybrids have been
released (personal communication, R.C. Olver). The
single-cross hybrid, SR 52, released in 1960, replaced
SR 14 because it was higher yielding. For more than
two decades, SR 52 has continued to be the dominant
hybrid in Zimbabwe (grown on 85% of hybrid area)
and is also widely grown in other African countries
(Billing 1985). Two shorter season hybrids, R 200 and
R 201, are grown on the remaining 15% of the hybrid
maize area. R 201 has tended to replace R 200, which
is susceptible to weevil damage (Billing 1985).









IMPROVED MAIZE VARIETIES AND HYBRIDS


UGANDA
Maize is an important staple in Uganda. During
1983-85, approximately 365,000 t of grain were pro-
duced annually on 358,000 ha, with national yields
averaging 1.2 t/ha.
The Ugandan maize program has been destroyed
by internal war and must be rebuilt. Cooperation with
IITA and CIMMYT will be very important in supplying
populations and inbred lines (personal communica-
tion, Oguti W. Mangheni). IITA has supplied
streak-resistant material for the lowland areas and has
been assisting in converting local varieties to streak
resistance. The Ugandan maize program is also inter-
ested in releasing varieties from CIMMYT Popula-
tions 21 (Tuxpeiio-1), 22 (Mezcla Tropical Blanca, 43
(La Posta), and 49 (Blanco Dentado-2) (Kaahwa and
Kabeere 1985).
The most popular improved open-pollinated varie-
ties in Uganda are Kawanda Composite A and Katu-
mani, a Kenyan variety used in the semi-arid Karamoja
region. Some hybrid seed is also imported from Kenya,
mainly H 622, H 632, and H 614. The Uganda Seed
Project (USP) is responsible for the production of
improved seed, which is marketed by farmers' coop-
eratives as well as by the USP. The Karamoja Seed
Scheme also produces improved seed for farmers in
that region.

ZAMBIA
Maize is the most important crop in Zambia. It is
grown in most regions of the country, except in excep-
tionally dry, wet, or infertile areas where sorghum,
millet, or cassava are better adapted. During 1983-85,
approximately 863,000 t of grain were produced annu-
ally on 512,000 ha, with national yields averaging 1.7 t/
ha, among the highest in sub-Saharan Africa.
Hybrids dominate commercial production areas,
and open-pollinated varieties dominate subsistence
agriculture areas. Approximately 30% of the total
maize area is planted with hybrids and 15% with
improved open-pollinated varieties and composites
(Chibasa 1985). Maize streak virus can cause serious
economic losses in certain years (personal communi-
cation, S.K. Kim).
CIMMYT and IITA collaborate with Zambian
maize researchers, and international trials from both
IARCs are regularly received and grown. Two
open-pollinated varieties based on CIMMYT germplasm
have been released by the national program. Since
1980, scientists in a joint Zambia/FAO research proj-


ect have screened over 200 streak-resistant lines in a
national hybrid development program. A collaborative
Zambian/Yugoslavian maize program has also used
IITA lines for hybrid development IITA's streak-resistant
mid-altitude population (TZMSR-W) and several of
the CIMMYT/IITA streak-resistant conversions of
experimental varieties show promise in Zambia (per-
sonal communication, S.K. Kim).
The Zambia Seed Company (Zamseed) has been
responsible for the production, procurement, and dis-
tribution of maize seed. The seed is produced by
farmers in the Zambian Seed Producers Association,
and quality control is conducted by the Seed Control
and Certification Institute. The main hybrid in use is
SR 52 (single-cross) which was developed in Zim-
babwe. In 1983, an improved version of SR 52, named
MM 752, was released and has shown great promise. In
1984, seven other hybrids were released: MM 501, MM
504, MM 602, MM 603, MM 604, and MM 606. In
addition, two open-pollinated varieties based on
CIMMYT materials, MMV 400 (Pirsabak (2) 7930,
Pop. 30, Blanco Cristalino-1) and MMV 600 (Pop. 21,
Tuxpefio-1), were also released and are being exten-
sively grown. These new cultivars provide Zambian
maize producers with the needed flexibility to adjust
planting dates according to the onset and duration of
the rainy season (Chibasa 1985).

ZIMBABWE
Maize is the principal staple in Zimbabwe. During
1983-85, approximately 1.7 million t of grain were
produced annually on 1.3 million ha, with national
yields averaging 1.2 t/ha. Both total production and
yields during this 2-year period were 25% below aver-
age due to severe drought. In most years, Zimbabwe is
a net maize exporter.
Zimbabwe's maize breeding program was started
in 1932 and is one of the oldest in Africa. The initial
genotypes developed were open-pollinated varieties.
In 1950, Southern Cross was the dominant variety
grown in the country. Since then, 14 double, 5 three-way,
6 single, and 6 modified single-cross hybrids have been
released (personal communication, R.C. Olver). The
single-cross hybrid, SR 52, released in 1960, replaced
SR 14 because it was higher yielding. For more than
two decades, SR 52 has continued to be the dominant
hybrid in Zimbabwe (grown on 85% of hybrid area)
and is also widely grown in other African countries
(Billing 1985). Two shorter season hybrids, R 200 and
R 201, are grown on the remaining 15% of the hybrid
maize area. R 201 has tended to replace R 200, which
is susceptible to weevil damage (Billing 1985).








IMPROVED MAIZE VARIETIES AND HYBRIDS


of maize and the communal farmers plant about 1,000,000
ha. Commercial yields generally average 5 to 6 t/ha
while the communal group yields average between 1
and 2 t/ha. Since Independence, the Zimbabwe Gov-
ernment has given priority to increasing yields among
the communal farmers: considerable headway in trans-
ferring improved varieties and production technolo-
gies has been made during the 1980s.

Western and Central Africa

BENIN
Maize is the major food staple in Benin. During
1983-85, approximately 370,000 t of grain were pro-
duced annually on 485,000 ha, with national yields
averaging 0.7 t/ha.
The national maize program cooperates with
CIMMYT, IITA, and SAFGRAD. The variety TZB
received from ITA is grown in the northern region; an
experimental variety from TZSR-W-1 is also being
extensively used in on-farm testing. Kpatcha-Kpatcha
(Poza Rica 7843-SR) and Pirsabak (Pirsabak (1)
7930-SR) from the CIMMYT/IITA joint program
have been introduced into the southern region.

BURKINA FASO
Maize is the third most important cereal grain,
after millet and sorghum. During 1983-85, approxi-
mately 90,000 t of grain were produced annually on
128,000 ha, with national yields averaging 0.7 t/ha.
The national maize program cooperates with
CIMMYT, IITA, and SAFGRAD, which is headquar-
tered in Burkina Faso. Safita-2, derived from CIM-
MYT Pool 16, has been released. In addition, a
streak-resistant version derived from CIMMYT Popu-
lation 21 (Tuxpefio-1) is being considered for release in
the southern areas. The Burkina Faso/IRAT maize
program selected two ITA hybrids, 8322-13, and 8428-19
in 1985 for commercial release (personal communica-
tion, S.K. Kim)

CAMEROON
Maize is the major food staple in Cameroon. Dur-
ing 1983-85, approximately 510,000 t of grain were
produced annually on 443,000 ha, with national yields
averaging 1.2 t/ha.
The national maize program cooperates with IITA
and CIMMYT. IITA currently has resident maize staff
stationed in the country as part of the USAID-supported
National Cereals and Extension Project. The IITA
staff posted in Cameroon focus their work on varietal


improvement for lowland, mid-altitude, and highland
ecologies. In view of the importance of maize streak
virus in the lowland areas, only streak-resistant varie-
ties are being released. Several streak-resistant varie-
ties based on IITA populations and the CIMMYT/
IITA conversion program have been released: TZB
and TZPB are currently grown on approximately 10,000
ha. Since 1984, IITA hybrids have been tested exten-
sively; some of these hybrids are showing tolerance to
Striga (personal communication, S.K. Kim).

CENTRAL AFRICAN REPUBLIC
Maize is an important food crop in the Central
African Republic. In 1983, approximately 30,000 t of
grain were produced annually on 100,000 ha, with the
average national yield equal to 0.3 t/ha, the lowest in
sub-Saharan Africa.
Tuxpefio-1 was introduced in the early 1980s and is
being used. International variety trials were supplied
by CIMMYT in 1983 and 1984 to research stations in
Soumbe and N'Goulinga; the best varieties in these
trials had yields 60% above the local checks (personal
communication, M. Bjarnason). Particularly promis-
ing are varieties from Populations 22, 32, and 43.

COTE D'IVOIRE
Maize has become a very important staple food for
most of the population of C6te d'Ivoire. During 1983-85,
approximately 478,000 t of grain were produced annu-
ally on 575,000 ha, with national yields averaging 0.8 t/
ha. Both yellow and white flour is used, depending on
tribal customs. The grain is used as human food in
diverse forms. Recently, more maize is being used as
animal feed.
The C6te d'Ivoire national maize program has
been developing both improved populations and inbred
lines for a hybrid program (personal communication,
H. Dosso). Improved germplasm from CIMMYT has
been extensively used since 1975 and 20 experimental
varieties have been developed. Tuxpefio P.B. is widely
grown in the country. The CIMMYT/IITA material
converted to streak virus resistant populations, e.g. EV
8428-SR and EV 8435-SR, has also been used exten-
sively. The program requests promising experimental
varieties from both IARCs to use as varieties per se or
germplasm for their breeding program. The Pioneer
Hi-Bred International program in C8te d'Ivoire is
using IITA's streak-resistant lines and has identified a
superior hybrid combination between an IITA inbred
line and an inbred line from Pioneer's maize program
in Thailand (personal communication, S.K. Kim). The








IMPROVED MAIZE VARIETIES AND HYBRIDS


of maize and the communal farmers plant about 1,000,000
ha. Commercial yields generally average 5 to 6 t/ha
while the communal group yields average between 1
and 2 t/ha. Since Independence, the Zimbabwe Gov-
ernment has given priority to increasing yields among
the communal farmers: considerable headway in trans-
ferring improved varieties and production technolo-
gies has been made during the 1980s.

Western and Central Africa

BENIN
Maize is the major food staple in Benin. During
1983-85, approximately 370,000 t of grain were pro-
duced annually on 485,000 ha, with national yields
averaging 0.7 t/ha.
The national maize program cooperates with
CIMMYT, IITA, and SAFGRAD. The variety TZB
received from ITA is grown in the northern region; an
experimental variety from TZSR-W-1 is also being
extensively used in on-farm testing. Kpatcha-Kpatcha
(Poza Rica 7843-SR) and Pirsabak (Pirsabak (1)
7930-SR) from the CIMMYT/IITA joint program
have been introduced into the southern region.

BURKINA FASO
Maize is the third most important cereal grain,
after millet and sorghum. During 1983-85, approxi-
mately 90,000 t of grain were produced annually on
128,000 ha, with national yields averaging 0.7 t/ha.
The national maize program cooperates with
CIMMYT, IITA, and SAFGRAD, which is headquar-
tered in Burkina Faso. Safita-2, derived from CIM-
MYT Pool 16, has been released. In addition, a
streak-resistant version derived from CIMMYT Popu-
lation 21 (Tuxpefio-1) is being considered for release in
the southern areas. The Burkina Faso/IRAT maize
program selected two ITA hybrids, 8322-13, and 8428-19
in 1985 for commercial release (personal communica-
tion, S.K. Kim)

CAMEROON
Maize is the major food staple in Cameroon. Dur-
ing 1983-85, approximately 510,000 t of grain were
produced annually on 443,000 ha, with national yields
averaging 1.2 t/ha.
The national maize program cooperates with IITA
and CIMMYT. IITA currently has resident maize staff
stationed in the country as part of the USAID-supported
National Cereals and Extension Project. The IITA
staff posted in Cameroon focus their work on varietal


improvement for lowland, mid-altitude, and highland
ecologies. In view of the importance of maize streak
virus in the lowland areas, only streak-resistant varie-
ties are being released. Several streak-resistant varie-
ties based on IITA populations and the CIMMYT/
IITA conversion program have been released: TZB
and TZPB are currently grown on approximately 10,000
ha. Since 1984, IITA hybrids have been tested exten-
sively; some of these hybrids are showing tolerance to
Striga (personal communication, S.K. Kim).

CENTRAL AFRICAN REPUBLIC
Maize is an important food crop in the Central
African Republic. In 1983, approximately 30,000 t of
grain were produced annually on 100,000 ha, with the
average national yield equal to 0.3 t/ha, the lowest in
sub-Saharan Africa.
Tuxpefio-1 was introduced in the early 1980s and is
being used. International variety trials were supplied
by CIMMYT in 1983 and 1984 to research stations in
Soumbe and N'Goulinga; the best varieties in these
trials had yields 60% above the local checks (personal
communication, M. Bjarnason). Particularly promis-
ing are varieties from Populations 22, 32, and 43.

COTE D'IVOIRE
Maize has become a very important staple food for
most of the population of C6te d'Ivoire. During 1983-85,
approximately 478,000 t of grain were produced annu-
ally on 575,000 ha, with national yields averaging 0.8 t/
ha. Both yellow and white flour is used, depending on
tribal customs. The grain is used as human food in
diverse forms. Recently, more maize is being used as
animal feed.
The C6te d'Ivoire national maize program has
been developing both improved populations and inbred
lines for a hybrid program (personal communication,
H. Dosso). Improved germplasm from CIMMYT has
been extensively used since 1975 and 20 experimental
varieties have been developed. Tuxpefio P.B. is widely
grown in the country. The CIMMYT/IITA material
converted to streak virus resistant populations, e.g. EV
8428-SR and EV 8435-SR, has also been used exten-
sively. The program requests promising experimental
varieties from both IARCs to use as varieties per se or
germplasm for their breeding program. The Pioneer
Hi-Bred International program in C8te d'Ivoire is
using IITA's streak-resistant lines and has identified a
superior hybrid combination between an IITA inbred
line and an inbred line from Pioneer's maize program
in Thailand (personal communication, S.K. Kim). The








IMPROVED MAIZE VARIETIES AND HYBRIDS


of maize and the communal farmers plant about 1,000,000
ha. Commercial yields generally average 5 to 6 t/ha
while the communal group yields average between 1
and 2 t/ha. Since Independence, the Zimbabwe Gov-
ernment has given priority to increasing yields among
the communal farmers: considerable headway in trans-
ferring improved varieties and production technolo-
gies has been made during the 1980s.

Western and Central Africa

BENIN
Maize is the major food staple in Benin. During
1983-85, approximately 370,000 t of grain were pro-
duced annually on 485,000 ha, with national yields
averaging 0.7 t/ha.
The national maize program cooperates with
CIMMYT, IITA, and SAFGRAD. The variety TZB
received from ITA is grown in the northern region; an
experimental variety from TZSR-W-1 is also being
extensively used in on-farm testing. Kpatcha-Kpatcha
(Poza Rica 7843-SR) and Pirsabak (Pirsabak (1)
7930-SR) from the CIMMYT/IITA joint program
have been introduced into the southern region.

BURKINA FASO
Maize is the third most important cereal grain,
after millet and sorghum. During 1983-85, approxi-
mately 90,000 t of grain were produced annually on
128,000 ha, with national yields averaging 0.7 t/ha.
The national maize program cooperates with
CIMMYT, IITA, and SAFGRAD, which is headquar-
tered in Burkina Faso. Safita-2, derived from CIM-
MYT Pool 16, has been released. In addition, a
streak-resistant version derived from CIMMYT Popu-
lation 21 (Tuxpefio-1) is being considered for release in
the southern areas. The Burkina Faso/IRAT maize
program selected two ITA hybrids, 8322-13, and 8428-19
in 1985 for commercial release (personal communica-
tion, S.K. Kim)

CAMEROON
Maize is the major food staple in Cameroon. Dur-
ing 1983-85, approximately 510,000 t of grain were
produced annually on 443,000 ha, with national yields
averaging 1.2 t/ha.
The national maize program cooperates with IITA
and CIMMYT. IITA currently has resident maize staff
stationed in the country as part of the USAID-supported
National Cereals and Extension Project. The IITA
staff posted in Cameroon focus their work on varietal


improvement for lowland, mid-altitude, and highland
ecologies. In view of the importance of maize streak
virus in the lowland areas, only streak-resistant varie-
ties are being released. Several streak-resistant varie-
ties based on IITA populations and the CIMMYT/
IITA conversion program have been released: TZB
and TZPB are currently grown on approximately 10,000
ha. Since 1984, IITA hybrids have been tested exten-
sively; some of these hybrids are showing tolerance to
Striga (personal communication, S.K. Kim).

CENTRAL AFRICAN REPUBLIC
Maize is an important food crop in the Central
African Republic. In 1983, approximately 30,000 t of
grain were produced annually on 100,000 ha, with the
average national yield equal to 0.3 t/ha, the lowest in
sub-Saharan Africa.
Tuxpefio-1 was introduced in the early 1980s and is
being used. International variety trials were supplied
by CIMMYT in 1983 and 1984 to research stations in
Soumbe and N'Goulinga; the best varieties in these
trials had yields 60% above the local checks (personal
communication, M. Bjarnason). Particularly promis-
ing are varieties from Populations 22, 32, and 43.

COTE D'IVOIRE
Maize has become a very important staple food for
most of the population of C6te d'Ivoire. During 1983-85,
approximately 478,000 t of grain were produced annu-
ally on 575,000 ha, with national yields averaging 0.8 t/
ha. Both yellow and white flour is used, depending on
tribal customs. The grain is used as human food in
diverse forms. Recently, more maize is being used as
animal feed.
The C6te d'Ivoire national maize program has
been developing both improved populations and inbred
lines for a hybrid program (personal communication,
H. Dosso). Improved germplasm from CIMMYT has
been extensively used since 1975 and 20 experimental
varieties have been developed. Tuxpefio P.B. is widely
grown in the country. The CIMMYT/IITA material
converted to streak virus resistant populations, e.g. EV
8428-SR and EV 8435-SR, has also been used exten-
sively. The program requests promising experimental
varieties from both IARCs to use as varieties per se or
germplasm for their breeding program. The Pioneer
Hi-Bred International program in C8te d'Ivoire is
using IITA's streak-resistant lines and has identified a
superior hybrid combination between an IITA inbred
line and an inbred line from Pioneer's maize program
in Thailand (personal communication, S.K. Kim). The








IMPROVED MAIZE VARIETIES AND HYBRIDS


of maize and the communal farmers plant about 1,000,000
ha. Commercial yields generally average 5 to 6 t/ha
while the communal group yields average between 1
and 2 t/ha. Since Independence, the Zimbabwe Gov-
ernment has given priority to increasing yields among
the communal farmers: considerable headway in trans-
ferring improved varieties and production technolo-
gies has been made during the 1980s.

Western and Central Africa

BENIN
Maize is the major food staple in Benin. During
1983-85, approximately 370,000 t of grain were pro-
duced annually on 485,000 ha, with national yields
averaging 0.7 t/ha.
The national maize program cooperates with
CIMMYT, IITA, and SAFGRAD. The variety TZB
received from ITA is grown in the northern region; an
experimental variety from TZSR-W-1 is also being
extensively used in on-farm testing. Kpatcha-Kpatcha
(Poza Rica 7843-SR) and Pirsabak (Pirsabak (1)
7930-SR) from the CIMMYT/IITA joint program
have been introduced into the southern region.

BURKINA FASO
Maize is the third most important cereal grain,
after millet and sorghum. During 1983-85, approxi-
mately 90,000 t of grain were produced annually on
128,000 ha, with national yields averaging 0.7 t/ha.
The national maize program cooperates with
CIMMYT, IITA, and SAFGRAD, which is headquar-
tered in Burkina Faso. Safita-2, derived from CIM-
MYT Pool 16, has been released. In addition, a
streak-resistant version derived from CIMMYT Popu-
lation 21 (Tuxpefio-1) is being considered for release in
the southern areas. The Burkina Faso/IRAT maize
program selected two ITA hybrids, 8322-13, and 8428-19
in 1985 for commercial release (personal communica-
tion, S.K. Kim)

CAMEROON
Maize is the major food staple in Cameroon. Dur-
ing 1983-85, approximately 510,000 t of grain were
produced annually on 443,000 ha, with national yields
averaging 1.2 t/ha.
The national maize program cooperates with IITA
and CIMMYT. IITA currently has resident maize staff
stationed in the country as part of the USAID-supported
National Cereals and Extension Project. The IITA
staff posted in Cameroon focus their work on varietal


improvement for lowland, mid-altitude, and highland
ecologies. In view of the importance of maize streak
virus in the lowland areas, only streak-resistant varie-
ties are being released. Several streak-resistant varie-
ties based on IITA populations and the CIMMYT/
IITA conversion program have been released: TZB
and TZPB are currently grown on approximately 10,000
ha. Since 1984, IITA hybrids have been tested exten-
sively; some of these hybrids are showing tolerance to
Striga (personal communication, S.K. Kim).

CENTRAL AFRICAN REPUBLIC
Maize is an important food crop in the Central
African Republic. In 1983, approximately 30,000 t of
grain were produced annually on 100,000 ha, with the
average national yield equal to 0.3 t/ha, the lowest in
sub-Saharan Africa.
Tuxpefio-1 was introduced in the early 1980s and is
being used. International variety trials were supplied
by CIMMYT in 1983 and 1984 to research stations in
Soumbe and N'Goulinga; the best varieties in these
trials had yields 60% above the local checks (personal
communication, M. Bjarnason). Particularly promis-
ing are varieties from Populations 22, 32, and 43.

COTE D'IVOIRE
Maize has become a very important staple food for
most of the population of C6te d'Ivoire. During 1983-85,
approximately 478,000 t of grain were produced annu-
ally on 575,000 ha, with national yields averaging 0.8 t/
ha. Both yellow and white flour is used, depending on
tribal customs. The grain is used as human food in
diverse forms. Recently, more maize is being used as
animal feed.
The C6te d'Ivoire national maize program has
been developing both improved populations and inbred
lines for a hybrid program (personal communication,
H. Dosso). Improved germplasm from CIMMYT has
been extensively used since 1975 and 20 experimental
varieties have been developed. Tuxpefio P.B. is widely
grown in the country. The CIMMYT/IITA material
converted to streak virus resistant populations, e.g. EV
8428-SR and EV 8435-SR, has also been used exten-
sively. The program requests promising experimental
varieties from both IARCs to use as varieties per se or
germplasm for their breeding program. The Pioneer
Hi-Bred International program in C8te d'Ivoire is
using IITA's streak-resistant lines and has identified a
superior hybrid combination between an IITA inbred
line and an inbred line from Pioneer's maize program
in Thailand (personal communication, S.K. Kim). The








IMPROVED MAIZE VARIETIES AND HYBRIDS


of maize and the communal farmers plant about 1,000,000
ha. Commercial yields generally average 5 to 6 t/ha
while the communal group yields average between 1
and 2 t/ha. Since Independence, the Zimbabwe Gov-
ernment has given priority to increasing yields among
the communal farmers: considerable headway in trans-
ferring improved varieties and production technolo-
gies has been made during the 1980s.

Western and Central Africa

BENIN
Maize is the major food staple in Benin. During
1983-85, approximately 370,000 t of grain were pro-
duced annually on 485,000 ha, with national yields
averaging 0.7 t/ha.
The national maize program cooperates with
CIMMYT, IITA, and SAFGRAD. The variety TZB
received from ITA is grown in the northern region; an
experimental variety from TZSR-W-1 is also being
extensively used in on-farm testing. Kpatcha-Kpatcha
(Poza Rica 7843-SR) and Pirsabak (Pirsabak (1)
7930-SR) from the CIMMYT/IITA joint program
have been introduced into the southern region.

BURKINA FASO
Maize is the third most important cereal grain,
after millet and sorghum. During 1983-85, approxi-
mately 90,000 t of grain were produced annually on
128,000 ha, with national yields averaging 0.7 t/ha.
The national maize program cooperates with
CIMMYT, IITA, and SAFGRAD, which is headquar-
tered in Burkina Faso. Safita-2, derived from CIM-
MYT Pool 16, has been released. In addition, a
streak-resistant version derived from CIMMYT Popu-
lation 21 (Tuxpefio-1) is being considered for release in
the southern areas. The Burkina Faso/IRAT maize
program selected two ITA hybrids, 8322-13, and 8428-19
in 1985 for commercial release (personal communica-
tion, S.K. Kim)

CAMEROON
Maize is the major food staple in Cameroon. Dur-
ing 1983-85, approximately 510,000 t of grain were
produced annually on 443,000 ha, with national yields
averaging 1.2 t/ha.
The national maize program cooperates with IITA
and CIMMYT. IITA currently has resident maize staff
stationed in the country as part of the USAID-supported
National Cereals and Extension Project. The IITA
staff posted in Cameroon focus their work on varietal


improvement for lowland, mid-altitude, and highland
ecologies. In view of the importance of maize streak
virus in the lowland areas, only streak-resistant varie-
ties are being released. Several streak-resistant varie-
ties based on IITA populations and the CIMMYT/
IITA conversion program have been released: TZB
and TZPB are currently grown on approximately 10,000
ha. Since 1984, IITA hybrids have been tested exten-
sively; some of these hybrids are showing tolerance to
Striga (personal communication, S.K. Kim).

CENTRAL AFRICAN REPUBLIC
Maize is an important food crop in the Central
African Republic. In 1983, approximately 30,000 t of
grain were produced annually on 100,000 ha, with the
average national yield equal to 0.3 t/ha, the lowest in
sub-Saharan Africa.
Tuxpefio-1 was introduced in the early 1980s and is
being used. International variety trials were supplied
by CIMMYT in 1983 and 1984 to research stations in
Soumbe and N'Goulinga; the best varieties in these
trials had yields 60% above the local checks (personal
communication, M. Bjarnason). Particularly promis-
ing are varieties from Populations 22, 32, and 43.

COTE D'IVOIRE
Maize has become a very important staple food for
most of the population of C6te d'Ivoire. During 1983-85,
approximately 478,000 t of grain were produced annu-
ally on 575,000 ha, with national yields averaging 0.8 t/
ha. Both yellow and white flour is used, depending on
tribal customs. The grain is used as human food in
diverse forms. Recently, more maize is being used as
animal feed.
The C6te d'Ivoire national maize program has
been developing both improved populations and inbred
lines for a hybrid program (personal communication,
H. Dosso). Improved germplasm from CIMMYT has
been extensively used since 1975 and 20 experimental
varieties have been developed. Tuxpefio P.B. is widely
grown in the country. The CIMMYT/IITA material
converted to streak virus resistant populations, e.g. EV
8428-SR and EV 8435-SR, has also been used exten-
sively. The program requests promising experimental
varieties from both IARCs to use as varieties per se or
germplasm for their breeding program. The Pioneer
Hi-Bred International program in C8te d'Ivoire is
using IITA's streak-resistant lines and has identified a
superior hybrid combination between an IITA inbred
line and an inbred line from Pioneer's maize program
in Thailand (personal communication, S.K. Kim). The








IMPROVED MAIZE VARIETIES AND HYBRIDS


of maize and the communal farmers plant about 1,000,000
ha. Commercial yields generally average 5 to 6 t/ha
while the communal group yields average between 1
and 2 t/ha. Since Independence, the Zimbabwe Gov-
ernment has given priority to increasing yields among
the communal farmers: considerable headway in trans-
ferring improved varieties and production technolo-
gies has been made during the 1980s.

Western and Central Africa

BENIN
Maize is the major food staple in Benin. During
1983-85, approximately 370,000 t of grain were pro-
duced annually on 485,000 ha, with national yields
averaging 0.7 t/ha.
The national maize program cooperates with
CIMMYT, IITA, and SAFGRAD. The variety TZB
received from ITA is grown in the northern region; an
experimental variety from TZSR-W-1 is also being
extensively used in on-farm testing. Kpatcha-Kpatcha
(Poza Rica 7843-SR) and Pirsabak (Pirsabak (1)
7930-SR) from the CIMMYT/IITA joint program
have been introduced into the southern region.

BURKINA FASO
Maize is the third most important cereal grain,
after millet and sorghum. During 1983-85, approxi-
mately 90,000 t of grain were produced annually on
128,000 ha, with national yields averaging 0.7 t/ha.
The national maize program cooperates with
CIMMYT, IITA, and SAFGRAD, which is headquar-
tered in Burkina Faso. Safita-2, derived from CIM-
MYT Pool 16, has been released. In addition, a
streak-resistant version derived from CIMMYT Popu-
lation 21 (Tuxpefio-1) is being considered for release in
the southern areas. The Burkina Faso/IRAT maize
program selected two ITA hybrids, 8322-13, and 8428-19
in 1985 for commercial release (personal communica-
tion, S.K. Kim)

CAMEROON
Maize is the major food staple in Cameroon. Dur-
ing 1983-85, approximately 510,000 t of grain were
produced annually on 443,000 ha, with national yields
averaging 1.2 t/ha.
The national maize program cooperates with IITA
and CIMMYT. IITA currently has resident maize staff
stationed in the country as part of the USAID-supported
National Cereals and Extension Project. The IITA
staff posted in Cameroon focus their work on varietal


improvement for lowland, mid-altitude, and highland
ecologies. In view of the importance of maize streak
virus in the lowland areas, only streak-resistant varie-
ties are being released. Several streak-resistant varie-
ties based on IITA populations and the CIMMYT/
IITA conversion program have been released: TZB
and TZPB are currently grown on approximately 10,000
ha. Since 1984, IITA hybrids have been tested exten-
sively; some of these hybrids are showing tolerance to
Striga (personal communication, S.K. Kim).

CENTRAL AFRICAN REPUBLIC
Maize is an important food crop in the Central
African Republic. In 1983, approximately 30,000 t of
grain were produced annually on 100,000 ha, with the
average national yield equal to 0.3 t/ha, the lowest in
sub-Saharan Africa.
Tuxpefio-1 was introduced in the early 1980s and is
being used. International variety trials were supplied
by CIMMYT in 1983 and 1984 to research stations in
Soumbe and N'Goulinga; the best varieties in these
trials had yields 60% above the local checks (personal
communication, M. Bjarnason). Particularly promis-
ing are varieties from Populations 22, 32, and 43.

COTE D'IVOIRE
Maize has become a very important staple food for
most of the population of C6te d'Ivoire. During 1983-85,
approximately 478,000 t of grain were produced annu-
ally on 575,000 ha, with national yields averaging 0.8 t/
ha. Both yellow and white flour is used, depending on
tribal customs. The grain is used as human food in
diverse forms. Recently, more maize is being used as
animal feed.
The C6te d'Ivoire national maize program has
been developing both improved populations and inbred
lines for a hybrid program (personal communication,
H. Dosso). Improved germplasm from CIMMYT has
been extensively used since 1975 and 20 experimental
varieties have been developed. Tuxpefio P.B. is widely
grown in the country. The CIMMYT/IITA material
converted to streak virus resistant populations, e.g. EV
8428-SR and EV 8435-SR, has also been used exten-
sively. The program requests promising experimental
varieties from both IARCs to use as varieties per se or
germplasm for their breeding program. The Pioneer
Hi-Bred International program in C8te d'Ivoire is
using IITA's streak-resistant lines and has identified a
superior hybrid combination between an IITA inbred
line and an inbred line from Pioneer's maize program
in Thailand (personal communication, S.K. Kim). The








RECENT RELEASES


designation "FERKE" is used on experimental varie-
ties, but is changed to "IDSA" when released.
In the past, seed production and distribution has
been the responsibility of the state seed company,
BETPA. Recently the Government has provided addi-
tional funds to the Ministry of Rural Development to
improve public-sector seed production and distribu-
tion systems. BETPA has switched from the local land
variety CJB to IDSA 29 (Ferke 7928, Pop. 28 Amarillo
Dentado) for a late variety and IDSA 28 (Ferke 7635,
Pop. 35, Antigua-Rep. Dominicana) for an early vari-
ety (IDESSA 1984). Other varieties that have been
released by the national program and include CIM-
MYT germplasm are IDSA 26 (Ferke 7529, Pop. 29,
Tuxpefo Caribe), IDSA 27 (Ferke 7622, Pop. 22,
Mezcla Tropical Blanca), and IRAT 81 (a variety
hybrid whose female parent is Tuxpefio brachytic).

GAMBIA
Maize is not a significant crop in Gambia. The area
planted with maize is 5,000 ha, though the total is
growing. Only improved open-pollinated varieties are
planted (personal communication A.G. Carson). The
Ministry of Agriculture cooperates with CIMMYT-
testing early maturing varieties-and with IITA, testing
early, streak virus, and Striga (witchweed) resistant
varieties. Research is aimed at improved open-pollinated
varieties. Cooperation with the IARCs has been good.
The Government's Seed Multiplication Unit dis-
tributes some seed of improved open-pollinated varie-
ties.

GHANA
Maize is the major food staple in Ghana. During
1983-85, approximately 402,000 t of grain were pro-
duced annually on 418,000 ha, with national yields
averaging 1.0 t/ha. Small-scale farmers account for
90% of national production. The majority of maize is
intercropped, primarily with cassava and cocoyam in
southern Ghana and with sorghum, millet, groundnuts,
and cowpeas in the Guinea savannah.
The Ghana Grains Development Project (GGDP)
was launched in 1979 with the objective of making
Ghana self-sufficient in maize production (GGDP
1986). As of 1987 CIMMYT had two maize scientists
and IITA had one cowpea scientist assigned to this
project. Objectives of the GGDP maize breeding pro-
gram are to develop the following maize materials:
1. 120-day white dent varieties for the forest and
transition zones in the major rainy season. These meet
about 60% of the national varietal requirement.


2.105-day, white dent varieties for the minor rainy
season in the forest and transition zone. These meet
about 20% of the national varietal requirement.
3.90-day, yellow flint varieties for early planting in
the Guinea savannah. These meet about 5% of the
national varietal requirement.
4. 90-day soft white dent varieties for use in the
Coastal and Guinea savannas. These meet about 5% of
the national varietal requirement.
5.100-day yellow dent varieties for use throughout
Ghana. These account for about 10% of the national
varietal requirement.
To date, three improved varieties, La Posta, Com-
posite 4, and Golden Crystal-all full-season white
dents derived from CIMMYT material-are widely
grown. In addition, an earlier (105-day) white dent,
Safita 2 (based on CIMMYT's Pool 16), has been
released for use during the minor rainy season in the
forest and transition zone. Improved open-pollinated
varieties are used on a substantial portion of the total
maize area, and the three above-mentioned full-season
varieties are grown on 25% to 30% of the total national
maize area. Recently, two new varieties based on
CIMMYT germplasm have been released: Dobidi CRI
1, derived from Ejira (1) 7843, and Aburotia CRI 1,
derived from Tuxpefio P.B. C16. Even though not
officially released, IITA supplied, upon request, 2 t of
TZESR-W to the Ghana Seed Company in 1983 for
seed multiplication and distribution in the Volta re-
gion.

LIBERIA
Maize is grown on only about 15,000 ha nationally
(personal communication, Cyril E. Broderick). The
national maize program receives open-pollinated va-
rieties, full-sib progeny, and various disease-resistant
high yielding hybrids from IITA. It started receiving
variety trials from CIMMYT in 1982, and varieties
from Populations 21, 23, 28, and 43 have performed
well. In addition to testing these materials for local
adaption, some selection is being done locally. The
Central Agricultural Research Institute (CARI) is
making some crosses.
Most of the breeding program is aimed at im-
proved open-pollinated varieties. Only a very limited
amount of effort is used in inbred line development. At
present, no releases of improved varieties have been
made, though they do have several promising lines.
Hybrids are very rare and would make up less than 1%
of plantings. Maize production has been increasing at








RECENT RELEASES


designation "FERKE" is used on experimental varie-
ties, but is changed to "IDSA" when released.
In the past, seed production and distribution has
been the responsibility of the state seed company,
BETPA. Recently the Government has provided addi-
tional funds to the Ministry of Rural Development to
improve public-sector seed production and distribu-
tion systems. BETPA has switched from the local land
variety CJB to IDSA 29 (Ferke 7928, Pop. 28 Amarillo
Dentado) for a late variety and IDSA 28 (Ferke 7635,
Pop. 35, Antigua-Rep. Dominicana) for an early vari-
ety (IDESSA 1984). Other varieties that have been
released by the national program and include CIM-
MYT germplasm are IDSA 26 (Ferke 7529, Pop. 29,
Tuxpefo Caribe), IDSA 27 (Ferke 7622, Pop. 22,
Mezcla Tropical Blanca), and IRAT 81 (a variety
hybrid whose female parent is Tuxpefio brachytic).

GAMBIA
Maize is not a significant crop in Gambia. The area
planted with maize is 5,000 ha, though the total is
growing. Only improved open-pollinated varieties are
planted (personal communication A.G. Carson). The
Ministry of Agriculture cooperates with CIMMYT-
testing early maturing varieties-and with IITA, testing
early, streak virus, and Striga (witchweed) resistant
varieties. Research is aimed at improved open-pollinated
varieties. Cooperation with the IARCs has been good.
The Government's Seed Multiplication Unit dis-
tributes some seed of improved open-pollinated varie-
ties.

GHANA
Maize is the major food staple in Ghana. During
1983-85, approximately 402,000 t of grain were pro-
duced annually on 418,000 ha, with national yields
averaging 1.0 t/ha. Small-scale farmers account for
90% of national production. The majority of maize is
intercropped, primarily with cassava and cocoyam in
southern Ghana and with sorghum, millet, groundnuts,
and cowpeas in the Guinea savannah.
The Ghana Grains Development Project (GGDP)
was launched in 1979 with the objective of making
Ghana self-sufficient in maize production (GGDP
1986). As of 1987 CIMMYT had two maize scientists
and IITA had one cowpea scientist assigned to this
project. Objectives of the GGDP maize breeding pro-
gram are to develop the following maize materials:
1. 120-day white dent varieties for the forest and
transition zones in the major rainy season. These meet
about 60% of the national varietal requirement.


2.105-day, white dent varieties for the minor rainy
season in the forest and transition zone. These meet
about 20% of the national varietal requirement.
3.90-day, yellow flint varieties for early planting in
the Guinea savannah. These meet about 5% of the
national varietal requirement.
4. 90-day soft white dent varieties for use in the
Coastal and Guinea savannas. These meet about 5% of
the national varietal requirement.
5.100-day yellow dent varieties for use throughout
Ghana. These account for about 10% of the national
varietal requirement.
To date, three improved varieties, La Posta, Com-
posite 4, and Golden Crystal-all full-season white
dents derived from CIMMYT material-are widely
grown. In addition, an earlier (105-day) white dent,
Safita 2 (based on CIMMYT's Pool 16), has been
released for use during the minor rainy season in the
forest and transition zone. Improved open-pollinated
varieties are used on a substantial portion of the total
maize area, and the three above-mentioned full-season
varieties are grown on 25% to 30% of the total national
maize area. Recently, two new varieties based on
CIMMYT germplasm have been released: Dobidi CRI
1, derived from Ejira (1) 7843, and Aburotia CRI 1,
derived from Tuxpefio P.B. C16. Even though not
officially released, IITA supplied, upon request, 2 t of
TZESR-W to the Ghana Seed Company in 1983 for
seed multiplication and distribution in the Volta re-
gion.

LIBERIA
Maize is grown on only about 15,000 ha nationally
(personal communication, Cyril E. Broderick). The
national maize program receives open-pollinated va-
rieties, full-sib progeny, and various disease-resistant
high yielding hybrids from IITA. It started receiving
variety trials from CIMMYT in 1982, and varieties
from Populations 21, 23, 28, and 43 have performed
well. In addition to testing these materials for local
adaption, some selection is being done locally. The
Central Agricultural Research Institute (CARI) is
making some crosses.
Most of the breeding program is aimed at im-
proved open-pollinated varieties. Only a very limited
amount of effort is used in inbred line development. At
present, no releases of improved varieties have been
made, though they do have several promising lines.
Hybrids are very rare and would make up less than 1%
of plantings. Maize production has been increasing at








RECENT RELEASES


designation "FERKE" is used on experimental varie-
ties, but is changed to "IDSA" when released.
In the past, seed production and distribution has
been the responsibility of the state seed company,
BETPA. Recently the Government has provided addi-
tional funds to the Ministry of Rural Development to
improve public-sector seed production and distribu-
tion systems. BETPA has switched from the local land
variety CJB to IDSA 29 (Ferke 7928, Pop. 28 Amarillo
Dentado) for a late variety and IDSA 28 (Ferke 7635,
Pop. 35, Antigua-Rep. Dominicana) for an early vari-
ety (IDESSA 1984). Other varieties that have been
released by the national program and include CIM-
MYT germplasm are IDSA 26 (Ferke 7529, Pop. 29,
Tuxpefo Caribe), IDSA 27 (Ferke 7622, Pop. 22,
Mezcla Tropical Blanca), and IRAT 81 (a variety
hybrid whose female parent is Tuxpefio brachytic).

GAMBIA
Maize is not a significant crop in Gambia. The area
planted with maize is 5,000 ha, though the total is
growing. Only improved open-pollinated varieties are
planted (personal communication A.G. Carson). The
Ministry of Agriculture cooperates with CIMMYT-
testing early maturing varieties-and with IITA, testing
early, streak virus, and Striga (witchweed) resistant
varieties. Research is aimed at improved open-pollinated
varieties. Cooperation with the IARCs has been good.
The Government's Seed Multiplication Unit dis-
tributes some seed of improved open-pollinated varie-
ties.

GHANA
Maize is the major food staple in Ghana. During
1983-85, approximately 402,000 t of grain were pro-
duced annually on 418,000 ha, with national yields
averaging 1.0 t/ha. Small-scale farmers account for
90% of national production. The majority of maize is
intercropped, primarily with cassava and cocoyam in
southern Ghana and with sorghum, millet, groundnuts,
and cowpeas in the Guinea savannah.
The Ghana Grains Development Project (GGDP)
was launched in 1979 with the objective of making
Ghana self-sufficient in maize production (GGDP
1986). As of 1987 CIMMYT had two maize scientists
and IITA had one cowpea scientist assigned to this
project. Objectives of the GGDP maize breeding pro-
gram are to develop the following maize materials:
1. 120-day white dent varieties for the forest and
transition zones in the major rainy season. These meet
about 60% of the national varietal requirement.


2.105-day, white dent varieties for the minor rainy
season in the forest and transition zone. These meet
about 20% of the national varietal requirement.
3.90-day, yellow flint varieties for early planting in
the Guinea savannah. These meet about 5% of the
national varietal requirement.
4. 90-day soft white dent varieties for use in the
Coastal and Guinea savannas. These meet about 5% of
the national varietal requirement.
5.100-day yellow dent varieties for use throughout
Ghana. These account for about 10% of the national
varietal requirement.
To date, three improved varieties, La Posta, Com-
posite 4, and Golden Crystal-all full-season white
dents derived from CIMMYT material-are widely
grown. In addition, an earlier (105-day) white dent,
Safita 2 (based on CIMMYT's Pool 16), has been
released for use during the minor rainy season in the
forest and transition zone. Improved open-pollinated
varieties are used on a substantial portion of the total
maize area, and the three above-mentioned full-season
varieties are grown on 25% to 30% of the total national
maize area. Recently, two new varieties based on
CIMMYT germplasm have been released: Dobidi CRI
1, derived from Ejira (1) 7843, and Aburotia CRI 1,
derived from Tuxpefio P.B. C16. Even though not
officially released, IITA supplied, upon request, 2 t of
TZESR-W to the Ghana Seed Company in 1983 for
seed multiplication and distribution in the Volta re-
gion.

LIBERIA
Maize is grown on only about 15,000 ha nationally
(personal communication, Cyril E. Broderick). The
national maize program receives open-pollinated va-
rieties, full-sib progeny, and various disease-resistant
high yielding hybrids from IITA. It started receiving
variety trials from CIMMYT in 1982, and varieties
from Populations 21, 23, 28, and 43 have performed
well. In addition to testing these materials for local
adaption, some selection is being done locally. The
Central Agricultural Research Institute (CARI) is
making some crosses.
Most of the breeding program is aimed at im-
proved open-pollinated varieties. Only a very limited
amount of effort is used in inbred line development. At
present, no releases of improved varieties have been
made, though they do have several promising lines.
Hybrids are very rare and would make up less than 1%
of plantings. Maize production has been increasing at








IMPROVED MAIZE VARIETIES AND HYBRIDS


Figure 10. Dr. S.K. Kim, IITA maize breeder, discusses
hybrid breeding work at a government arranged field
day in Lagos state, Nigeria, in 1985. Source: IITA.


a rate of 2% to 4% per year. Seed production is a major
bottleneck to increased production. There is no na-
tional seed production, but a few private companies
import seed.

NIGERIA
Maize is an important crop in Nigeria. During
1983-85, approximately 2.1 million t of grain were
produced annually on 2 million ha, with national yields
averaging 1.0 t/ha.
Maize improvement under the auspices of IITA
began with the formation and improvement of two
populations: TZB, which originated from bothAfrican
and Latin American sources, with Nigerian Composite
B most important; and TZPB, which is derived from
Tuxpeiio Planta Baja Cycle 7 from CIMMYT (per-
sonal communication, Y. Efron). These two were
released by the Nigerian National Program as FARZ
27 (TZPB) and FARZ 34 (TZB). Both varieties are full
season and have good resistance to tropical rust (Puc-
ciniapolysora) and lowland blight (Helminthosporium
maydis).


The National Accelerated Food Production Pro
gram (NAFPP) in Nigeria conducted a total of 10,21'
mini-kit trials in 15 states between 1974 and 1978
NAFPP distributed 728 t of seed of these two varieties:
to local farmers (1975 to 1978). Results of the mini-kit
trials showed an average 30% increase in yield com-
pared to local farmers' variety. It is estimated that these
two varieties are grown on about 1 million ha in
Nigeria.
More recently, streak-resistant variety conversion,
from CIMMYT Populations 28 (La Maquina 7928)
and 43 (Poza Rica 7843) have been released and are
being multiplied by the National Seed Service. Seed
multiplication of three additional new varieties has alsc
been recently initiated: TZMSR-W for the mid-altitude
ecology of Plateau State (combined MSV, H. turcicum
and P sorhi resistance) and DMRLSR-W and
DMRESR-W (combined MSV and downy mildew
resistance) for the maize areas affected with these
diseases in Ondo, Bendel, and Kwara States.
A joint IITA-Nigeria program was-as noted previ-
ously in the IITA portion of chapter 2-initiated in
1982. In 1984, IITA maize hybrids were tested in
on-farm demonstrations (a total of 150 ha) across
Nigeria. These plantings were made by Nigerian farm-
ers with the cooperation of both the Nigerian National
Research and Extension Organizations and the sup-
port of the Federal Government of Nigeria. Selected
hybrids produced between 25% to 60% more yield
than the check variety, TZSR-W-1. Two private seed
companies have been recently formed (with IITA as-
sistance) to produce these hybrids: Agricultural Seeds
Nigeria and the Limited and Temperance Seed Com-
pany. Under the supervision of IITA and the National
Seed Service personnel, the two companies produced
about 600 t of eight hybrids in 1985 for planting in the
1986 season (personal communication, Y, Efron). In
1986, approximately 1,600 t of hybrid seed were pro-
duced, enough to plant 90,000 to 100,000 ha.

SENEGAL
Maize is becoming an increasingly important crop
in Senegal. During 1983-85, approximately 101,000 t
were produced annually on 84,000 ha, with national
yields averaging 1.2 t/ha. During the past 5 years,
maize production has doubled. The Senegalese gov-
ernment objective is to attain self-sufficiency (400,000
t) by 1989.
The Institut Senegalais De Recherches Agricoles
receives material from both CIMMYT and IITA
(personal communication, Papa Assau Camara). The
tropical material tested is selected for early maturing








IMPROVED MAIZE VARIETIES AND HYBRIDS


Figure 10. Dr. S.K. Kim, IITA maize breeder, discusses
hybrid breeding work at a government arranged field
day in Lagos state, Nigeria, in 1985. Source: IITA.


a rate of 2% to 4% per year. Seed production is a major
bottleneck to increased production. There is no na-
tional seed production, but a few private companies
import seed.

NIGERIA
Maize is an important crop in Nigeria. During
1983-85, approximately 2.1 million t of grain were
produced annually on 2 million ha, with national yields
averaging 1.0 t/ha.
Maize improvement under the auspices of IITA
began with the formation and improvement of two
populations: TZB, which originated from bothAfrican
and Latin American sources, with Nigerian Composite
B most important; and TZPB, which is derived from
Tuxpeiio Planta Baja Cycle 7 from CIMMYT (per-
sonal communication, Y. Efron). These two were
released by the Nigerian National Program as FARZ
27 (TZPB) and FARZ 34 (TZB). Both varieties are full
season and have good resistance to tropical rust (Puc-
ciniapolysora) and lowland blight (Helminthosporium
maydis).


The National Accelerated Food Production Pro
gram (NAFPP) in Nigeria conducted a total of 10,21'
mini-kit trials in 15 states between 1974 and 1978
NAFPP distributed 728 t of seed of these two varieties:
to local farmers (1975 to 1978). Results of the mini-kit
trials showed an average 30% increase in yield com-
pared to local farmers' variety. It is estimated that these
two varieties are grown on about 1 million ha in
Nigeria.
More recently, streak-resistant variety conversion,
from CIMMYT Populations 28 (La Maquina 7928)
and 43 (Poza Rica 7843) have been released and are
being multiplied by the National Seed Service. Seed
multiplication of three additional new varieties has alsc
been recently initiated: TZMSR-W for the mid-altitude
ecology of Plateau State (combined MSV, H. turcicum
and P sorhi resistance) and DMRLSR-W and
DMRESR-W (combined MSV and downy mildew
resistance) for the maize areas affected with these
diseases in Ondo, Bendel, and Kwara States.
A joint IITA-Nigeria program was-as noted previ-
ously in the IITA portion of chapter 2-initiated in
1982. In 1984, IITA maize hybrids were tested in
on-farm demonstrations (a total of 150 ha) across
Nigeria. These plantings were made by Nigerian farm-
ers with the cooperation of both the Nigerian National
Research and Extension Organizations and the sup-
port of the Federal Government of Nigeria. Selected
hybrids produced between 25% to 60% more yield
than the check variety, TZSR-W-1. Two private seed
companies have been recently formed (with IITA as-
sistance) to produce these hybrids: Agricultural Seeds
Nigeria and the Limited and Temperance Seed Com-
pany. Under the supervision of IITA and the National
Seed Service personnel, the two companies produced
about 600 t of eight hybrids in 1985 for planting in the
1986 season (personal communication, Y, Efron). In
1986, approximately 1,600 t of hybrid seed were pro-
duced, enough to plant 90,000 to 100,000 ha.

SENEGAL
Maize is becoming an increasingly important crop
in Senegal. During 1983-85, approximately 101,000 t
were produced annually on 84,000 ha, with national
yields averaging 1.2 t/ha. During the past 5 years,
maize production has doubled. The Senegalese gov-
ernment objective is to attain self-sufficiency (400,000
t) by 1989.
The Institut Senegalais De Recherches Agricoles
receives material from both CIMMYT and IITA
(personal communication, Papa Assau Camara). The
tropical material tested is selected for early maturing









RECENT RELEASES


types (90 days, not to exceed 110-120 days). A unique
rainy season of 3 to 4 months limits growing of a
full-season crop in Senegal. White flinty grain maize is
preferred for human food, but some yellow and semi-dent
types are used by industries.
The local program created a synthetic variety using
material from IITA for adaption to African conditions
and unrelated genetic material from CIMMYT to
select for high combining performance with the IITA
material. Some CIMMYT materials have been distrib-
uted to farmers after local selection. They include
Camasa 1, based on Tocumen (1) 7835 from CIM-
MYT, and two quality protein maize varieties based on
Obregon 7740 and Temperate White QPM, also from
CIMMYT.
National germplasm development emphasizes
open-pollinated varieties. They have three levels of
selections based on the level of farmer's technology for
the intended use of the developed variety. One is the
creation of varietal hybrids from crosses of
composites-usually between one local variety and an
introduced material. To obtain the best specific plants,
reciprocal recurrent selection techniques are used.
These hybrids are intended for farmers having a high
technology for maize production. The second level is
the creation of synthetic varieties and composites ob-
tained from full-sib selection. These genotypes are
intended for farmers having an intermediate-level
technology. The third level is local population im-
provement by simple recurrent selection methods to
develop improved genotypes from local populations
for farmers with low technology.
There is a national seed service and a bilateral
project with West Germany to promote maize produc-
tion. The research stations furnish foundation seeds to
the national seed service-German project, and they in
turn contract with farmers to produce seed. The coop-
erative project buys the seed and distributes it to the
rural extension agencies, which sell directly to their
farmers. The maize improvement program recom-
mends the following:

Hybrids: BOS 111, HVB-1
Varieties: Synthetic C, Camara 1, APM1 and
APM2, CP75 white and yellow com-
posites
Local
population: ZM10 (eastern Senegal)

Source: Personal communication, Papa Assau
Camara.


SIERRA LEONE
Maize is not a major crop in Sierra Leone. During
1983-85, approximately 20,000 t of grain were pro-
duced annually on 14,000 ha, with national yields aver-
age 1.4 t/ha.
Material for testing is received from both CIM-
MYT and IITA, and cooperation with these IARCs has
been good (personal communication, E.R. Rhodes).
Three groups of maize trials are received from both
IARCs and these are tested locally. Some work is
under way to add local adaptation to the most promis-
ing selections. This local research is aimed mostly at
developing improved local open-pollinated varieties
for farm use. Only 10% of the research is concerned
with inbred and hybrid development. Two populations
have been released for farmer use: TZSR (yellow) and
TZPB (white). All the production is open-pollinated
varieties. Maize seed is distributed by the Extension
Service and private farmers.

TOGO
Maize is an important food crop in Togo. During
1983-85, approximately 191,000 t of grain were pro-
duced annually on 179,000 ha, with national yields
averaging 1.1 t/ha.
The national maize program cooperates with both
I1TA and CIMMYT (personal communication, Wilfried
Schwieber). La Posta, originally from CIMMYT, is the
most widely grown improved variety in Togo. More
recently, two streak-resistant varieties based on CIM-
MYT/IITA germplasm, Poza Rica 7843-SR and Pirsa-
bak (1) 7930-SR, have been released and are being
multiplied by a Federal Republic of Germany (GTZ)
project in Sotouboua. Cooperation with IITA involves
improved streak resistance in open-pollinated varieties
(both white and yellow grained). CIMMYT open-
pollinated white and yellow varieties are also being
tested. Some research to develop low-input technolo-
gies for the agroforestry zones is also underway. Five
open-pollinated varieties have been released to farm-
ers, with four based on CIMMYT germplasm. Ferme
Semenciere de Sotouboua is the national governmen-
tal seed company; approximately 120 t of seed is
produced per year.

ZAIRE

Maize is the major cereal grain produced in Zaire.
During 1983-85, approximately 709,000 t of grain were
produced annually on 822,000 ha, with national yields
averaging 0.9 t/ha.









RECENT RELEASES


types (90 days, not to exceed 110-120 days). A unique
rainy season of 3 to 4 months limits growing of a
full-season crop in Senegal. White flinty grain maize is
preferred for human food, but some yellow and semi-dent
types are used by industries.
The local program created a synthetic variety using
material from IITA for adaption to African conditions
and unrelated genetic material from CIMMYT to
select for high combining performance with the IITA
material. Some CIMMYT materials have been distrib-
uted to farmers after local selection. They include
Camasa 1, based on Tocumen (1) 7835 from CIM-
MYT, and two quality protein maize varieties based on
Obregon 7740 and Temperate White QPM, also from
CIMMYT.
National germplasm development emphasizes
open-pollinated varieties. They have three levels of
selections based on the level of farmer's technology for
the intended use of the developed variety. One is the
creation of varietal hybrids from crosses of
composites-usually between one local variety and an
introduced material. To obtain the best specific plants,
reciprocal recurrent selection techniques are used.
These hybrids are intended for farmers having a high
technology for maize production. The second level is
the creation of synthetic varieties and composites ob-
tained from full-sib selection. These genotypes are
intended for farmers having an intermediate-level
technology. The third level is local population im-
provement by simple recurrent selection methods to
develop improved genotypes from local populations
for farmers with low technology.
There is a national seed service and a bilateral
project with West Germany to promote maize produc-
tion. The research stations furnish foundation seeds to
the national seed service-German project, and they in
turn contract with farmers to produce seed. The coop-
erative project buys the seed and distributes it to the
rural extension agencies, which sell directly to their
farmers. The maize improvement program recom-
mends the following:

Hybrids: BOS 111, HVB-1
Varieties: Synthetic C, Camara 1, APM1 and
APM2, CP75 white and yellow com-
posites
Local
population: ZM10 (eastern Senegal)

Source: Personal communication, Papa Assau
Camara.


SIERRA LEONE
Maize is not a major crop in Sierra Leone. During
1983-85, approximately 20,000 t of grain were pro-
duced annually on 14,000 ha, with national yields aver-
age 1.4 t/ha.
Material for testing is received from both CIM-
MYT and IITA, and cooperation with these IARCs has
been good (personal communication, E.R. Rhodes).
Three groups of maize trials are received from both
IARCs and these are tested locally. Some work is
under way to add local adaptation to the most promis-
ing selections. This local research is aimed mostly at
developing improved local open-pollinated varieties
for farm use. Only 10% of the research is concerned
with inbred and hybrid development. Two populations
have been released for farmer use: TZSR (yellow) and
TZPB (white). All the production is open-pollinated
varieties. Maize seed is distributed by the Extension
Service and private farmers.

TOGO
Maize is an important food crop in Togo. During
1983-85, approximately 191,000 t of grain were pro-
duced annually on 179,000 ha, with national yields
averaging 1.1 t/ha.
The national maize program cooperates with both
I1TA and CIMMYT (personal communication, Wilfried
Schwieber). La Posta, originally from CIMMYT, is the
most widely grown improved variety in Togo. More
recently, two streak-resistant varieties based on CIM-
MYT/IITA germplasm, Poza Rica 7843-SR and Pirsa-
bak (1) 7930-SR, have been released and are being
multiplied by a Federal Republic of Germany (GTZ)
project in Sotouboua. Cooperation with IITA involves
improved streak resistance in open-pollinated varieties
(both white and yellow grained). CIMMYT open-
pollinated white and yellow varieties are also being
tested. Some research to develop low-input technolo-
gies for the agroforestry zones is also underway. Five
open-pollinated varieties have been released to farm-
ers, with four based on CIMMYT germplasm. Ferme
Semenciere de Sotouboua is the national governmen-
tal seed company; approximately 120 t of seed is
produced per year.

ZAIRE

Maize is the major cereal grain produced in Zaire.
During 1983-85, approximately 709,000 t of grain were
produced annually on 822,000 ha, with national yields
averaging 0.9 t/ha.









RECENT RELEASES


types (90 days, not to exceed 110-120 days). A unique
rainy season of 3 to 4 months limits growing of a
full-season crop in Senegal. White flinty grain maize is
preferred for human food, but some yellow and semi-dent
types are used by industries.
The local program created a synthetic variety using
material from IITA for adaption to African conditions
and unrelated genetic material from CIMMYT to
select for high combining performance with the IITA
material. Some CIMMYT materials have been distrib-
uted to farmers after local selection. They include
Camasa 1, based on Tocumen (1) 7835 from CIM-
MYT, and two quality protein maize varieties based on
Obregon 7740 and Temperate White QPM, also from
CIMMYT.
National germplasm development emphasizes
open-pollinated varieties. They have three levels of
selections based on the level of farmer's technology for
the intended use of the developed variety. One is the
creation of varietal hybrids from crosses of
composites-usually between one local variety and an
introduced material. To obtain the best specific plants,
reciprocal recurrent selection techniques are used.
These hybrids are intended for farmers having a high
technology for maize production. The second level is
the creation of synthetic varieties and composites ob-
tained from full-sib selection. These genotypes are
intended for farmers having an intermediate-level
technology. The third level is local population im-
provement by simple recurrent selection methods to
develop improved genotypes from local populations
for farmers with low technology.
There is a national seed service and a bilateral
project with West Germany to promote maize produc-
tion. The research stations furnish foundation seeds to
the national seed service-German project, and they in
turn contract with farmers to produce seed. The coop-
erative project buys the seed and distributes it to the
rural extension agencies, which sell directly to their
farmers. The maize improvement program recom-
mends the following:

Hybrids: BOS 111, HVB-1
Varieties: Synthetic C, Camara 1, APM1 and
APM2, CP75 white and yellow com-
posites
Local
population: ZM10 (eastern Senegal)

Source: Personal communication, Papa Assau
Camara.


SIERRA LEONE
Maize is not a major crop in Sierra Leone. During
1983-85, approximately 20,000 t of grain were pro-
duced annually on 14,000 ha, with national yields aver-
age 1.4 t/ha.
Material for testing is received from both CIM-
MYT and IITA, and cooperation with these IARCs has
been good (personal communication, E.R. Rhodes).
Three groups of maize trials are received from both
IARCs and these are tested locally. Some work is
under way to add local adaptation to the most promis-
ing selections. This local research is aimed mostly at
developing improved local open-pollinated varieties
for farm use. Only 10% of the research is concerned
with inbred and hybrid development. Two populations
have been released for farmer use: TZSR (yellow) and
TZPB (white). All the production is open-pollinated
varieties. Maize seed is distributed by the Extension
Service and private farmers.

TOGO
Maize is an important food crop in Togo. During
1983-85, approximately 191,000 t of grain were pro-
duced annually on 179,000 ha, with national yields
averaging 1.1 t/ha.
The national maize program cooperates with both
I1TA and CIMMYT (personal communication, Wilfried
Schwieber). La Posta, originally from CIMMYT, is the
most widely grown improved variety in Togo. More
recently, two streak-resistant varieties based on CIM-
MYT/IITA germplasm, Poza Rica 7843-SR and Pirsa-
bak (1) 7930-SR, have been released and are being
multiplied by a Federal Republic of Germany (GTZ)
project in Sotouboua. Cooperation with IITA involves
improved streak resistance in open-pollinated varieties
(both white and yellow grained). CIMMYT open-
pollinated white and yellow varieties are also being
tested. Some research to develop low-input technolo-
gies for the agroforestry zones is also underway. Five
open-pollinated varieties have been released to farm-
ers, with four based on CIMMYT germplasm. Ferme
Semenciere de Sotouboua is the national governmen-
tal seed company; approximately 120 t of seed is
produced per year.

ZAIRE

Maize is the major cereal grain produced in Zaire.
During 1983-85, approximately 709,000 t of grain were
produced annually on 822,000 ha, with national yields
averaging 0.9 t/ha.









IMPROVED MAIZE VARIETIES AND HYBRIDS


The Programme National Mais has cooperated
closely with CIMMYT and IITA for many years (per-
sonal communication, Mulamba Ngandu Nyindu).
Between 1971 and 1981, CIMMYT had maize staff
assigned to work with the national program at Lubum-
bashi. It receives the full complement of experimental
materials available from the Center. IITA populations
also have been used in crosses with the local Zairian
varieties. Populations TZDMRSR-W, TZDMRSR-Y,
TZMSR-W, and TZEMSR-W have shown high levels
of resistance to one or more of the following diseases:
downy mildew, maize streak virus, and H. turcicum.
Currently, IITA is involved in a substantial bilateral
maize research assistance project, sponsored by USAID,
with the national maize program and has several maize
scientists stationed in the country.
The national program has released four open-
pollinated varieties from the CIMMYT material:

Salongo: 10 best families of Tuxpefio 1, C11
Kasai 1: Tuxpefio x Eto Blanco
PNM 1.: (Tuxpefio and Mix Colima grl I and
ETO Blanco) x Shaba Safi
Shaba I: Tuxpefio x Eto Blanco x Shaba Safi

Most Zairian farmers plant open-pollinated varie-
ties. A few imported hybrids are grown in the southern
part of Shaba province. A hybrid program has been
initiated and inbreds are being developed. No seed
organization exists, and access to seed of improved
varieties is limited.

NORTH AFRICA AND
THE MIDDLE EAST

North Africa

EGYPT
Maize is the major cereal grain produced in Egypt.
During 1983-85, approximately 3.6 million t of grain
were produced annually on 805,000 ha, with national
yields averaging 4.4 t/ha. Virtually all maize is pro-
duced under irrigation.
Maize research is carried out by the national maize
program, Cairo University, and several private compa-
nies. National germplasm improvement priorities are
to develop high-yielding hybrids and open-pollinated


varieties-white and yellow grain-with resistance to
late wilt and stalk rot diseases caused by Cephalospo-
rium maydis, to H. turcicum leaf blight, and to Ustilago
maydis (personal communication, W. Haag). The na-
tional maize program has had close collaborative links
with CIMMYT for two decades, and several CIMMYT
maize staff members have been stationed in Egypt
during this time period. IITA's inbred lines have been
screened by maize researchers in national programs
and private companies for resistance to late wilt (per-
sonal communication, S.K. Kim).
The major improved varieties in use are:
1. Giza-2, an open-pollinated variety with late-wilt
tolerance covering 25% of the total maize area. This
variety is based on 50% of American Early Dent
(AED), developed locally, and 50% of tropical germplasm
(Pop. 21) obtained from CIMMYT in the 1969-70
period.
2. P-514, a Pioneer hybrid.
3. DC-202, an AED x Tep.-5 hybrid developed by
the national program.
4. Kahera-1, a open-pollinated variety developed
by Cairo University.
Certified seed production of these materials during
1984 totaled 8,700 t and was distributed as follows:
DC-202, 2,800 t; Giza-2, 4,400 t; P-514, 1,000 t; and
Kahera-1, 500 t (unpublished report, W. Haag).
The national maize program released several new
hybrids during 1983-84, all of which are based on AED
x Tep.-5 crosses: DC-204, DC-215 (double crosses);
TWC-9 and TWC-10 (3-way crosses) (unpublished
report, W. Haag). Inbreeding is being conducted in
CIMMYT material in support of national hybrid devel-
opment efforts. Inbred lines from the following mate-
rials had been developed: Tuxpefio C17; Tlaltizapan
7844; Gemmeiza 7421; (Ant. xRep. Dom) x Corn Belt;
Sids 7444; Pop. 45; Tuxpefio x ETO; Tep.5; and La
Posta. Sids 7444 continues to be a source of resistance
to late wilt and to H. turcicum.

MOROCCO
Maize is not a major crop in Morocco. During
1983-85, approximately 267,000 t of grain were pro-
duced annually on 405,000 ha, with national yields
averaging 0.7 t/ha.
CIMMYT is cooperating with the Moroccan na-
tional maize program to develop high-yielding hybrids
and open-pollinated varieties appropriate to dryland as
well as irrigated conditions. Progress has been made in









IMPROVED MAIZE VARIETIES AND HYBRIDS


The Programme National Mais has cooperated
closely with CIMMYT and IITA for many years (per-
sonal communication, Mulamba Ngandu Nyindu).
Between 1971 and 1981, CIMMYT had maize staff
assigned to work with the national program at Lubum-
bashi. It receives the full complement of experimental
materials available from the Center. IITA populations
also have been used in crosses with the local Zairian
varieties. Populations TZDMRSR-W, TZDMRSR-Y,
TZMSR-W, and TZEMSR-W have shown high levels
of resistance to one or more of the following diseases:
downy mildew, maize streak virus, and H. turcicum.
Currently, IITA is involved in a substantial bilateral
maize research assistance project, sponsored by USAID,
with the national maize program and has several maize
scientists stationed in the country.
The national program has released four open-
pollinated varieties from the CIMMYT material:

Salongo: 10 best families of Tuxpefio 1, C11
Kasai 1: Tuxpefio x Eto Blanco
PNM 1.: (Tuxpefio and Mix Colima grl I and
ETO Blanco) x Shaba Safi
Shaba I: Tuxpefio x Eto Blanco x Shaba Safi

Most Zairian farmers plant open-pollinated varie-
ties. A few imported hybrids are grown in the southern
part of Shaba province. A hybrid program has been
initiated and inbreds are being developed. No seed
organization exists, and access to seed of improved
varieties is limited.

NORTH AFRICA AND
THE MIDDLE EAST

North Africa

EGYPT
Maize is the major cereal grain produced in Egypt.
During 1983-85, approximately 3.6 million t of grain
were produced annually on 805,000 ha, with national
yields averaging 4.4 t/ha. Virtually all maize is pro-
duced under irrigation.
Maize research is carried out by the national maize
program, Cairo University, and several private compa-
nies. National germplasm improvement priorities are
to develop high-yielding hybrids and open-pollinated


varieties-white and yellow grain-with resistance to
late wilt and stalk rot diseases caused by Cephalospo-
rium maydis, to H. turcicum leaf blight, and to Ustilago
maydis (personal communication, W. Haag). The na-
tional maize program has had close collaborative links
with CIMMYT for two decades, and several CIMMYT
maize staff members have been stationed in Egypt
during this time period. IITA's inbred lines have been
screened by maize researchers in national programs
and private companies for resistance to late wilt (per-
sonal communication, S.K. Kim).
The major improved varieties in use are:
1. Giza-2, an open-pollinated variety with late-wilt
tolerance covering 25% of the total maize area. This
variety is based on 50% of American Early Dent
(AED), developed locally, and 50% of tropical germplasm
(Pop. 21) obtained from CIMMYT in the 1969-70
period.
2. P-514, a Pioneer hybrid.
3. DC-202, an AED x Tep.-5 hybrid developed by
the national program.
4. Kahera-1, a open-pollinated variety developed
by Cairo University.
Certified seed production of these materials during
1984 totaled 8,700 t and was distributed as follows:
DC-202, 2,800 t; Giza-2, 4,400 t; P-514, 1,000 t; and
Kahera-1, 500 t (unpublished report, W. Haag).
The national maize program released several new
hybrids during 1983-84, all of which are based on AED
x Tep.-5 crosses: DC-204, DC-215 (double crosses);
TWC-9 and TWC-10 (3-way crosses) (unpublished
report, W. Haag). Inbreeding is being conducted in
CIMMYT material in support of national hybrid devel-
opment efforts. Inbred lines from the following mate-
rials had been developed: Tuxpefio C17; Tlaltizapan
7844; Gemmeiza 7421; (Ant. xRep. Dom) x Corn Belt;
Sids 7444; Pop. 45; Tuxpefio x ETO; Tep.5; and La
Posta. Sids 7444 continues to be a source of resistance
to late wilt and to H. turcicum.

MOROCCO
Maize is not a major crop in Morocco. During
1983-85, approximately 267,000 t of grain were pro-
duced annually on 405,000 ha, with national yields
averaging 0.7 t/ha.
CIMMYT is cooperating with the Moroccan na-
tional maize program to develop high-yielding hybrids
and open-pollinated varieties appropriate to dryland as
well as irrigated conditions. Progress has been made in









IMPROVED MAIZE VARIETIES AND HYBRIDS


The Programme National Mais has cooperated
closely with CIMMYT and IITA for many years (per-
sonal communication, Mulamba Ngandu Nyindu).
Between 1971 and 1981, CIMMYT had maize staff
assigned to work with the national program at Lubum-
bashi. It receives the full complement of experimental
materials available from the Center. IITA populations
also have been used in crosses with the local Zairian
varieties. Populations TZDMRSR-W, TZDMRSR-Y,
TZMSR-W, and TZEMSR-W have shown high levels
of resistance to one or more of the following diseases:
downy mildew, maize streak virus, and H. turcicum.
Currently, IITA is involved in a substantial bilateral
maize research assistance project, sponsored by USAID,
with the national maize program and has several maize
scientists stationed in the country.
The national program has released four open-
pollinated varieties from the CIMMYT material:

Salongo: 10 best families of Tuxpefio 1, C11
Kasai 1: Tuxpefio x Eto Blanco
PNM 1.: (Tuxpefio and Mix Colima grl I and
ETO Blanco) x Shaba Safi
Shaba I: Tuxpefio x Eto Blanco x Shaba Safi

Most Zairian farmers plant open-pollinated varie-
ties. A few imported hybrids are grown in the southern
part of Shaba province. A hybrid program has been
initiated and inbreds are being developed. No seed
organization exists, and access to seed of improved
varieties is limited.

NORTH AFRICA AND
THE MIDDLE EAST

North Africa

EGYPT
Maize is the major cereal grain produced in Egypt.
During 1983-85, approximately 3.6 million t of grain
were produced annually on 805,000 ha, with national
yields averaging 4.4 t/ha. Virtually all maize is pro-
duced under irrigation.
Maize research is carried out by the national maize
program, Cairo University, and several private compa-
nies. National germplasm improvement priorities are
to develop high-yielding hybrids and open-pollinated


varieties-white and yellow grain-with resistance to
late wilt and stalk rot diseases caused by Cephalospo-
rium maydis, to H. turcicum leaf blight, and to Ustilago
maydis (personal communication, W. Haag). The na-
tional maize program has had close collaborative links
with CIMMYT for two decades, and several CIMMYT
maize staff members have been stationed in Egypt
during this time period. IITA's inbred lines have been
screened by maize researchers in national programs
and private companies for resistance to late wilt (per-
sonal communication, S.K. Kim).
The major improved varieties in use are:
1. Giza-2, an open-pollinated variety with late-wilt
tolerance covering 25% of the total maize area. This
variety is based on 50% of American Early Dent
(AED), developed locally, and 50% of tropical germplasm
(Pop. 21) obtained from CIMMYT in the 1969-70
period.
2. P-514, a Pioneer hybrid.
3. DC-202, an AED x Tep.-5 hybrid developed by
the national program.
4. Kahera-1, a open-pollinated variety developed
by Cairo University.
Certified seed production of these materials during
1984 totaled 8,700 t and was distributed as follows:
DC-202, 2,800 t; Giza-2, 4,400 t; P-514, 1,000 t; and
Kahera-1, 500 t (unpublished report, W. Haag).
The national maize program released several new
hybrids during 1983-84, all of which are based on AED
x Tep.-5 crosses: DC-204, DC-215 (double crosses);
TWC-9 and TWC-10 (3-way crosses) (unpublished
report, W. Haag). Inbreeding is being conducted in
CIMMYT material in support of national hybrid devel-
opment efforts. Inbred lines from the following mate-
rials had been developed: Tuxpefio C17; Tlaltizapan
7844; Gemmeiza 7421; (Ant. xRep. Dom) x Corn Belt;
Sids 7444; Pop. 45; Tuxpefio x ETO; Tep.5; and La
Posta. Sids 7444 continues to be a source of resistance
to late wilt and to H. turcicum.

MOROCCO
Maize is not a major crop in Morocco. During
1983-85, approximately 267,000 t of grain were pro-
duced annually on 405,000 ha, with national yields
averaging 0.7 t/ha.
CIMMYT is cooperating with the Moroccan na-
tional maize program to develop high-yielding hybrids
and open-pollinated varieties appropriate to dryland as
well as irrigated conditions. Progress has been made in









IMPROVED MAIZE VARIETIES AND HYBRIDS


The Programme National Mais has cooperated
closely with CIMMYT and IITA for many years (per-
sonal communication, Mulamba Ngandu Nyindu).
Between 1971 and 1981, CIMMYT had maize staff
assigned to work with the national program at Lubum-
bashi. It receives the full complement of experimental
materials available from the Center. IITA populations
also have been used in crosses with the local Zairian
varieties. Populations TZDMRSR-W, TZDMRSR-Y,
TZMSR-W, and TZEMSR-W have shown high levels
of resistance to one or more of the following diseases:
downy mildew, maize streak virus, and H. turcicum.
Currently, IITA is involved in a substantial bilateral
maize research assistance project, sponsored by USAID,
with the national maize program and has several maize
scientists stationed in the country.
The national program has released four open-
pollinated varieties from the CIMMYT material:

Salongo: 10 best families of Tuxpefio 1, C11
Kasai 1: Tuxpefio x Eto Blanco
PNM 1.: (Tuxpefio and Mix Colima grl I and
ETO Blanco) x Shaba Safi
Shaba I: Tuxpefio x Eto Blanco x Shaba Safi

Most Zairian farmers plant open-pollinated varie-
ties. A few imported hybrids are grown in the southern
part of Shaba province. A hybrid program has been
initiated and inbreds are being developed. No seed
organization exists, and access to seed of improved
varieties is limited.

NORTH AFRICA AND
THE MIDDLE EAST

North Africa

EGYPT
Maize is the major cereal grain produced in Egypt.
During 1983-85, approximately 3.6 million t of grain
were produced annually on 805,000 ha, with national
yields averaging 4.4 t/ha. Virtually all maize is pro-
duced under irrigation.
Maize research is carried out by the national maize
program, Cairo University, and several private compa-
nies. National germplasm improvement priorities are
to develop high-yielding hybrids and open-pollinated


varieties-white and yellow grain-with resistance to
late wilt and stalk rot diseases caused by Cephalospo-
rium maydis, to H. turcicum leaf blight, and to Ustilago
maydis (personal communication, W. Haag). The na-
tional maize program has had close collaborative links
with CIMMYT for two decades, and several CIMMYT
maize staff members have been stationed in Egypt
during this time period. IITA's inbred lines have been
screened by maize researchers in national programs
and private companies for resistance to late wilt (per-
sonal communication, S.K. Kim).
The major improved varieties in use are:
1. Giza-2, an open-pollinated variety with late-wilt
tolerance covering 25% of the total maize area. This
variety is based on 50% of American Early Dent
(AED), developed locally, and 50% of tropical germplasm
(Pop. 21) obtained from CIMMYT in the 1969-70
period.
2. P-514, a Pioneer hybrid.
3. DC-202, an AED x Tep.-5 hybrid developed by
the national program.
4. Kahera-1, a open-pollinated variety developed
by Cairo University.
Certified seed production of these materials during
1984 totaled 8,700 t and was distributed as follows:
DC-202, 2,800 t; Giza-2, 4,400 t; P-514, 1,000 t; and
Kahera-1, 500 t (unpublished report, W. Haag).
The national maize program released several new
hybrids during 1983-84, all of which are based on AED
x Tep.-5 crosses: DC-204, DC-215 (double crosses);
TWC-9 and TWC-10 (3-way crosses) (unpublished
report, W. Haag). Inbreeding is being conducted in
CIMMYT material in support of national hybrid devel-
opment efforts. Inbred lines from the following mate-
rials had been developed: Tuxpefio C17; Tlaltizapan
7844; Gemmeiza 7421; (Ant. xRep. Dom) x Corn Belt;
Sids 7444; Pop. 45; Tuxpefio x ETO; Tep.5; and La
Posta. Sids 7444 continues to be a source of resistance
to late wilt and to H. turcicum.

MOROCCO
Maize is not a major crop in Morocco. During
1983-85, approximately 267,000 t of grain were pro-
duced annually on 405,000 ha, with national yields
averaging 0.7 t/ha.
CIMMYT is cooperating with the Moroccan na-
tional maize program to develop high-yielding hybrids
and open-pollinated varieties appropriate to dryland as
well as irrigated conditions. Progress has been made in









RECENT RELEASES


Maize research began during the 1950s, in collabo-
ration with FAO. Approximately 30 U.S. hybrids were
compared with local varieties in multilocational trials.
Two double-cross U.S. hybrids, U.S. 13 and Wisconsin
641 AA, showed high yield potential and were released
for commercial production. Additional hybrids were
developed during the 1950s and 1960s by Turkish
maize breeders using local inbreds and lines from the
United States.
Because of inadequate production and distribution
of hybrid seed, and the subsistence nature of many
Turkish maize farmers, especially in the Black Sea
area, the Turkish national maize program began to
give more emphasis to the development of improved
open-pollinated varieties (OPVs). Three gene pools
were constituted using local and foreign germplasm:
TMP-1, TMP-2, and TMP-3. After making headway in
developing OPVs, the Turkish national program re-
newed its hybrid work in 1980 (personal communica-
tion, W. Haag). Some 150 public lines from the United
States were obtained for evaluation through assistance
from the CIMMYT Regional Maize Specialist sta-
tioned in Turkey. From these inbred lines, five hybrids


Table 5. Foreign hybrids registered in
Turkey in 1984-85


Figure 11. Maize researcher discusses improved
maize with farmer, Morocco. Source: CIMMYT.


developing improved materials for the irrigated and
higher rainfall areas of the north. U.S. germplasm is
playing a major role in the development of hybrids for
these areas; Pioneer Hi-Bred is active in this work.
Little progress has been made to date toward the
development of early, drought-tolerant materials for
the low-rainfall areas. Some promising materials for
these areas currently under evaluation include BS-5
from the United States and Pools 29 and 30 from
CIMMYT (personal communication, W. Haag).

Middle East

TURKEY
Maize is less important in Turkey than wheat and
barley, though it is becoming increasingly important as
a poultry feed. During 1983-85, approximately 1.6
million t of grain were produced annually on 560,000
ha, with national yields averaging 2.9 t/ha.


Company
Northrup King
(Tohum Islah)
Pioneer Inter-
national
Lima Grain (Sapek)
Dekalb

Ciba Geigy
Basagene (Bereket)

Jacques
Stauffer

Asgrow
Nickerson


Name of hybrid

Matador, Mirko, Silco
P-3360, P-3320, P-3184,
P-3183
LG-42, LG-55, LG-66
XL-72AA, DK-789,
DK-I-Peron
G-4524, G-5050
610MF, 714MF, 810MF,
M-7676, M-8161, M-84
Jx-8820, Jx-247, Jx-187A
S-4460, S-5540, S-6920,
S-6915
RX-90
Nickerson-702


Source: Wayne Haag, unpublished CIMMYT re-
port, 1985









RECENT RELEASES


Maize research began during the 1950s, in collabo-
ration with FAO. Approximately 30 U.S. hybrids were
compared with local varieties in multilocational trials.
Two double-cross U.S. hybrids, U.S. 13 and Wisconsin
641 AA, showed high yield potential and were released
for commercial production. Additional hybrids were
developed during the 1950s and 1960s by Turkish
maize breeders using local inbreds and lines from the
United States.
Because of inadequate production and distribution
of hybrid seed, and the subsistence nature of many
Turkish maize farmers, especially in the Black Sea
area, the Turkish national maize program began to
give more emphasis to the development of improved
open-pollinated varieties (OPVs). Three gene pools
were constituted using local and foreign germplasm:
TMP-1, TMP-2, and TMP-3. After making headway in
developing OPVs, the Turkish national program re-
newed its hybrid work in 1980 (personal communica-
tion, W. Haag). Some 150 public lines from the United
States were obtained for evaluation through assistance
from the CIMMYT Regional Maize Specialist sta-
tioned in Turkey. From these inbred lines, five hybrids


Table 5. Foreign hybrids registered in
Turkey in 1984-85


Figure 11. Maize researcher discusses improved
maize with farmer, Morocco. Source: CIMMYT.


developing improved materials for the irrigated and
higher rainfall areas of the north. U.S. germplasm is
playing a major role in the development of hybrids for
these areas; Pioneer Hi-Bred is active in this work.
Little progress has been made to date toward the
development of early, drought-tolerant materials for
the low-rainfall areas. Some promising materials for
these areas currently under evaluation include BS-5
from the United States and Pools 29 and 30 from
CIMMYT (personal communication, W. Haag).

Middle East

TURKEY
Maize is less important in Turkey than wheat and
barley, though it is becoming increasingly important as
a poultry feed. During 1983-85, approximately 1.6
million t of grain were produced annually on 560,000
ha, with national yields averaging 2.9 t/ha.


Company
Northrup King
(Tohum Islah)
Pioneer Inter-
national
Lima Grain (Sapek)
Dekalb

Ciba Geigy
Basagene (Bereket)

Jacques
Stauffer

Asgrow
Nickerson


Name of hybrid

Matador, Mirko, Silco
P-3360, P-3320, P-3184,
P-3183
LG-42, LG-55, LG-66
XL-72AA, DK-789,
DK-I-Peron
G-4524, G-5050
610MF, 714MF, 810MF,
M-7676, M-8161, M-84
Jx-8820, Jx-247, Jx-187A
S-4460, S-5540, S-6920,
S-6915
RX-90
Nickerson-702


Source: Wayne Haag, unpublished CIMMYT re-
port, 1985









IMPROVED MAIZE VARIETIES AND HYBRIDS


have been developed: three single crosses (TTM-813,
TTM-815, and TTM-815), one three-way cross
(TUM-827), and one double cross (TCM-811). Parent
lines all relate to U.S. public lines derived from Lancas-
ter x Stiff Stalk Synthetic.
Since 1984, many private seed companies with
international operations have established maize seed
production programs in Turkey and have registered a
number of "foreign" hybridsfor commercial sale (table
5).
With the growth in the private maize seed sector,
the role of the national maize program is being re-
viewed. While still under discussion, it appears that
public sector maize research will concentrate on devel-
oping OPVs and improved production practices for the
Black Sea area (personal communication, E. Kinace).
Important maize improvement objectives include the
development of high-yielding hybrids and open-pollinated
varieties with resistance to Fusarium stalk rot and H.
turcicum leaf blight and to two stalk borers, Ostringa
nubilalis and Sesamia cretica.
The major open-pollinated varieties in use are:
Karadeniz Yildizi (K3/74), formed by compositing
Yugoslavia hybrids and other germplasm; Ada, formed
from CIMMYT Compuesto de Hungaria, Pop. 48;
Sapanca, formed by compositing Compuesto de Hun-
garia and several tropical materials; and Arifye, a late,
tall variety used mainly for silage.

ASIA

South Asia

BURMA
Maize is the second most important cereal grown in
Burma, and production has been increasing rapidly
over the past 15 years. During 1983-85, approximately
317,000 t of grain were produced annually on 185,000
ha, with national yields averaging 1.7 t/ha.
CIMMYT supplies germplasm to the Burmese
national maize program (Zin 1986). In particular, the
drought tolerance (partially due to more extensive root
systems) of certain CIMMYT materials has been espe-
cially beneficial. A number of varieties have been
released by the national program, with most based on
CIMMYT germplasm (table 6).

INDIA
Maize ranks fifth in importance among the cereals
produced in India, after rice, wheat, sorghum, and


Table 6. Open-pollinated varieties released by
the Burmese National Maize Program and
based on CIMMYT germplasm

Grain
Name color Source material
Shwe-wa 1 Yellow La Calera (1) 7728
(Pop. 28)
Shwe-wa 2 Yellow Petrolina 7736 (Pop. 36)
Shwe-wa 3 Yellow Satipo (1) 7627 (Pop. 27)
Shwe-wa 4 Yellow Indonesian Early
Shwe-wa 7 White Tlaltizapan 7322 (Pop 22)
Shwe-wa 8 Yellow Across 7835 (Pop. 35)
Shwe-wa 9 Yellow Pichilingue 7931 (Pop. 31)
Shwe-wa 10 Yellow Fareko 8328 (Pop. 28)
Shwe-wa 11 Yellow Across 8331 (Pop. 31)

Source: CIMMYT Maize Program


millet. During 1983-85, approximately 7.8 million t of
grain were produced annually, with national yields
averaging 1.3 t/ha.
Indian maize research dates back to the colonial
time and to the work of the Imperial Council of
Agriculture. After independence in 1947, maize re-
search continued in various states under the auspices of
the Indian Council of Agricultural Research (ICAR).
A number of inbred lines and double-cross hybrids
were developed in Uttar Pradesh and Punjab states,
notably Punjab-1, Punjab-2, and Punjab-3; these,
however, were not very high yielding.
In 1957 the Indian Government and the Rockefeller
Foundation established a joint Coordinated Maize
Improvement Programme for India (Mikoshiba 1971).
The Rockefeller Foundation assigned several scien-
tists to work with Indian scientists in this new country-
wide maize breeding effort and provided financial
support and scholarships to strengthen national maize
efforts.
One of the first activities of RF and Indian scientists
working in the Coordinated Maize Improvement Pro-
gram was to collect and evaluate exotic germplasms
from other countries in order to broaden the germplasm
base available in India. Emphasis was on yellow flint
grain types. In particular, germplasm complexes from
Latin America proved to be useful, including ETO
from Colombia, Peru 330, Venezuela 1, Antigua Gr.1
from Antigua via Mexico, and Cuba 342 (Mikoshiba









IMPROVED MAIZE VARIETIES AND HYBRIDS


have been developed: three single crosses (TTM-813,
TTM-815, and TTM-815), one three-way cross
(TUM-827), and one double cross (TCM-811). Parent
lines all relate to U.S. public lines derived from Lancas-
ter x Stiff Stalk Synthetic.
Since 1984, many private seed companies with
international operations have established maize seed
production programs in Turkey and have registered a
number of "foreign" hybridsfor commercial sale (table
5).
With the growth in the private maize seed sector,
the role of the national maize program is being re-
viewed. While still under discussion, it appears that
public sector maize research will concentrate on devel-
oping OPVs and improved production practices for the
Black Sea area (personal communication, E. Kinace).
Important maize improvement objectives include the
development of high-yielding hybrids and open-pollinated
varieties with resistance to Fusarium stalk rot and H.
turcicum leaf blight and to two stalk borers, Ostringa
nubilalis and Sesamia cretica.
The major open-pollinated varieties in use are:
Karadeniz Yildizi (K3/74), formed by compositing
Yugoslavia hybrids and other germplasm; Ada, formed
from CIMMYT Compuesto de Hungaria, Pop. 48;
Sapanca, formed by compositing Compuesto de Hun-
garia and several tropical materials; and Arifye, a late,
tall variety used mainly for silage.

ASIA

South Asia

BURMA
Maize is the second most important cereal grown in
Burma, and production has been increasing rapidly
over the past 15 years. During 1983-85, approximately
317,000 t of grain were produced annually on 185,000
ha, with national yields averaging 1.7 t/ha.
CIMMYT supplies germplasm to the Burmese
national maize program (Zin 1986). In particular, the
drought tolerance (partially due to more extensive root
systems) of certain CIMMYT materials has been espe-
cially beneficial. A number of varieties have been
released by the national program, with most based on
CIMMYT germplasm (table 6).

INDIA
Maize ranks fifth in importance among the cereals
produced in India, after rice, wheat, sorghum, and


Table 6. Open-pollinated varieties released by
the Burmese National Maize Program and
based on CIMMYT germplasm

Grain
Name color Source material
Shwe-wa 1 Yellow La Calera (1) 7728
(Pop. 28)
Shwe-wa 2 Yellow Petrolina 7736 (Pop. 36)
Shwe-wa 3 Yellow Satipo (1) 7627 (Pop. 27)
Shwe-wa 4 Yellow Indonesian Early
Shwe-wa 7 White Tlaltizapan 7322 (Pop 22)
Shwe-wa 8 Yellow Across 7835 (Pop. 35)
Shwe-wa 9 Yellow Pichilingue 7931 (Pop. 31)
Shwe-wa 10 Yellow Fareko 8328 (Pop. 28)
Shwe-wa 11 Yellow Across 8331 (Pop. 31)

Source: CIMMYT Maize Program


millet. During 1983-85, approximately 7.8 million t of
grain were produced annually, with national yields
averaging 1.3 t/ha.
Indian maize research dates back to the colonial
time and to the work of the Imperial Council of
Agriculture. After independence in 1947, maize re-
search continued in various states under the auspices of
the Indian Council of Agricultural Research (ICAR).
A number of inbred lines and double-cross hybrids
were developed in Uttar Pradesh and Punjab states,
notably Punjab-1, Punjab-2, and Punjab-3; these,
however, were not very high yielding.
In 1957 the Indian Government and the Rockefeller
Foundation established a joint Coordinated Maize
Improvement Programme for India (Mikoshiba 1971).
The Rockefeller Foundation assigned several scien-
tists to work with Indian scientists in this new country-
wide maize breeding effort and provided financial
support and scholarships to strengthen national maize
efforts.
One of the first activities of RF and Indian scientists
working in the Coordinated Maize Improvement Pro-
gram was to collect and evaluate exotic germplasms
from other countries in order to broaden the germplasm
base available in India. Emphasis was on yellow flint
grain types. In particular, germplasm complexes from
Latin America proved to be useful, including ETO
from Colombia, Peru 330, Venezuela 1, Antigua Gr.1
from Antigua via Mexico, and Cuba 342 (Mikoshiba









IMPROVED MAIZE VARIETIES AND HYBRIDS


have been developed: three single crosses (TTM-813,
TTM-815, and TTM-815), one three-way cross
(TUM-827), and one double cross (TCM-811). Parent
lines all relate to U.S. public lines derived from Lancas-
ter x Stiff Stalk Synthetic.
Since 1984, many private seed companies with
international operations have established maize seed
production programs in Turkey and have registered a
number of "foreign" hybridsfor commercial sale (table
5).
With the growth in the private maize seed sector,
the role of the national maize program is being re-
viewed. While still under discussion, it appears that
public sector maize research will concentrate on devel-
oping OPVs and improved production practices for the
Black Sea area (personal communication, E. Kinace).
Important maize improvement objectives include the
development of high-yielding hybrids and open-pollinated
varieties with resistance to Fusarium stalk rot and H.
turcicum leaf blight and to two stalk borers, Ostringa
nubilalis and Sesamia cretica.
The major open-pollinated varieties in use are:
Karadeniz Yildizi (K3/74), formed by compositing
Yugoslavia hybrids and other germplasm; Ada, formed
from CIMMYT Compuesto de Hungaria, Pop. 48;
Sapanca, formed by compositing Compuesto de Hun-
garia and several tropical materials; and Arifye, a late,
tall variety used mainly for silage.

ASIA

South Asia

BURMA
Maize is the second most important cereal grown in
Burma, and production has been increasing rapidly
over the past 15 years. During 1983-85, approximately
317,000 t of grain were produced annually on 185,000
ha, with national yields averaging 1.7 t/ha.
CIMMYT supplies germplasm to the Burmese
national maize program (Zin 1986). In particular, the
drought tolerance (partially due to more extensive root
systems) of certain CIMMYT materials has been espe-
cially beneficial. A number of varieties have been
released by the national program, with most based on
CIMMYT germplasm (table 6).

INDIA
Maize ranks fifth in importance among the cereals
produced in India, after rice, wheat, sorghum, and


Table 6. Open-pollinated varieties released by
the Burmese National Maize Program and
based on CIMMYT germplasm

Grain
Name color Source material
Shwe-wa 1 Yellow La Calera (1) 7728
(Pop. 28)
Shwe-wa 2 Yellow Petrolina 7736 (Pop. 36)
Shwe-wa 3 Yellow Satipo (1) 7627 (Pop. 27)
Shwe-wa 4 Yellow Indonesian Early
Shwe-wa 7 White Tlaltizapan 7322 (Pop 22)
Shwe-wa 8 Yellow Across 7835 (Pop. 35)
Shwe-wa 9 Yellow Pichilingue 7931 (Pop. 31)
Shwe-wa 10 Yellow Fareko 8328 (Pop. 28)
Shwe-wa 11 Yellow Across 8331 (Pop. 31)

Source: CIMMYT Maize Program


millet. During 1983-85, approximately 7.8 million t of
grain were produced annually, with national yields
averaging 1.3 t/ha.
Indian maize research dates back to the colonial
time and to the work of the Imperial Council of
Agriculture. After independence in 1947, maize re-
search continued in various states under the auspices of
the Indian Council of Agricultural Research (ICAR).
A number of inbred lines and double-cross hybrids
were developed in Uttar Pradesh and Punjab states,
notably Punjab-1, Punjab-2, and Punjab-3; these,
however, were not very high yielding.
In 1957 the Indian Government and the Rockefeller
Foundation established a joint Coordinated Maize
Improvement Programme for India (Mikoshiba 1971).
The Rockefeller Foundation assigned several scien-
tists to work with Indian scientists in this new country-
wide maize breeding effort and provided financial
support and scholarships to strengthen national maize
efforts.
One of the first activities of RF and Indian scientists
working in the Coordinated Maize Improvement Pro-
gram was to collect and evaluate exotic germplasms
from other countries in order to broaden the germplasm
base available in India. Emphasis was on yellow flint
grain types. In particular, germplasm complexes from
Latin America proved to be useful, including ETO
from Colombia, Peru 330, Venezuela 1, Antigua Gr.1
from Antigua via Mexico, and Cuba 342 (Mikoshiba









IMPROVED MAIZE VARIETIES AND HYBRIDS


have been developed: three single crosses (TTM-813,
TTM-815, and TTM-815), one three-way cross
(TUM-827), and one double cross (TCM-811). Parent
lines all relate to U.S. public lines derived from Lancas-
ter x Stiff Stalk Synthetic.
Since 1984, many private seed companies with
international operations have established maize seed
production programs in Turkey and have registered a
number of "foreign" hybridsfor commercial sale (table
5).
With the growth in the private maize seed sector,
the role of the national maize program is being re-
viewed. While still under discussion, it appears that
public sector maize research will concentrate on devel-
oping OPVs and improved production practices for the
Black Sea area (personal communication, E. Kinace).
Important maize improvement objectives include the
development of high-yielding hybrids and open-pollinated
varieties with resistance to Fusarium stalk rot and H.
turcicum leaf blight and to two stalk borers, Ostringa
nubilalis and Sesamia cretica.
The major open-pollinated varieties in use are:
Karadeniz Yildizi (K3/74), formed by compositing
Yugoslavia hybrids and other germplasm; Ada, formed
from CIMMYT Compuesto de Hungaria, Pop. 48;
Sapanca, formed by compositing Compuesto de Hun-
garia and several tropical materials; and Arifye, a late,
tall variety used mainly for silage.

ASIA

South Asia

BURMA
Maize is the second most important cereal grown in
Burma, and production has been increasing rapidly
over the past 15 years. During 1983-85, approximately
317,000 t of grain were produced annually on 185,000
ha, with national yields averaging 1.7 t/ha.
CIMMYT supplies germplasm to the Burmese
national maize program (Zin 1986). In particular, the
drought tolerance (partially due to more extensive root
systems) of certain CIMMYT materials has been espe-
cially beneficial. A number of varieties have been
released by the national program, with most based on
CIMMYT germplasm (table 6).

INDIA
Maize ranks fifth in importance among the cereals
produced in India, after rice, wheat, sorghum, and


Table 6. Open-pollinated varieties released by
the Burmese National Maize Program and
based on CIMMYT germplasm

Grain
Name color Source material
Shwe-wa 1 Yellow La Calera (1) 7728
(Pop. 28)
Shwe-wa 2 Yellow Petrolina 7736 (Pop. 36)
Shwe-wa 3 Yellow Satipo (1) 7627 (Pop. 27)
Shwe-wa 4 Yellow Indonesian Early
Shwe-wa 7 White Tlaltizapan 7322 (Pop 22)
Shwe-wa 8 Yellow Across 7835 (Pop. 35)
Shwe-wa 9 Yellow Pichilingue 7931 (Pop. 31)
Shwe-wa 10 Yellow Fareko 8328 (Pop. 28)
Shwe-wa 11 Yellow Across 8331 (Pop. 31)

Source: CIMMYT Maize Program


millet. During 1983-85, approximately 7.8 million t of
grain were produced annually, with national yields
averaging 1.3 t/ha.
Indian maize research dates back to the colonial
time and to the work of the Imperial Council of
Agriculture. After independence in 1947, maize re-
search continued in various states under the auspices of
the Indian Council of Agricultural Research (ICAR).
A number of inbred lines and double-cross hybrids
were developed in Uttar Pradesh and Punjab states,
notably Punjab-1, Punjab-2, and Punjab-3; these,
however, were not very high yielding.
In 1957 the Indian Government and the Rockefeller
Foundation established a joint Coordinated Maize
Improvement Programme for India (Mikoshiba 1971).
The Rockefeller Foundation assigned several scien-
tists to work with Indian scientists in this new country-
wide maize breeding effort and provided financial
support and scholarships to strengthen national maize
efforts.
One of the first activities of RF and Indian scientists
working in the Coordinated Maize Improvement Pro-
gram was to collect and evaluate exotic germplasms
from other countries in order to broaden the germplasm
base available in India. Emphasis was on yellow flint
grain types. In particular, germplasm complexes from
Latin America proved to be useful, including ETO
from Colombia, Peru 330, Venezuela 1, Antigua Gr.1
from Antigua via Mexico, and Cuba 342 (Mikoshiba









RECENT RELEASES


Table 7. Background of composite maize varieties released in India in 1967

Grain
Name color Germplasm sources
Amber Yellow 11 varietal crosses involving five flint varieties (Narino 330,
Diacol VI, Venezuela 1, Corneli 54, Eto Amarillo) and six dent
varieties (Jarvis, Ferguson, Yellow Dent, Cocker 811 Gr/N
1000/1452, Mexican June, Bolita Amarilla)
Vijay Yellow J1 x Coastal Trop. Flints
Jawahar Yellow A1 x Antigua Gr. 1
Kisan Yellow Coastal Tropical Flint
Sona Yellow J1 x Cuba 11J
Vikram Yellow Basi x Eto Amarillo

Source: Maize in India, Haruo Mikoshiba, 1971.


1971). A large number (more than 4,000) of inbred
lines were developed from Indian and foreign
germplasms. By 1961, four double-cross hybrids-Ganga
1, Ganga 101, Ranjit, and Deccan-had been released
for commercial production.
Although the emphasis in the Coordinated Maize
Improvement Program was on hybrid development,
population improvement work was also carried out and
composite open-pollinated varieties and inter-varietal
hybrids were developed. Outstanding among these
populations were J-1 (also known as Naraingarh
Complex), and Sona (J1 x Cuba 11J). In 1967, six
high-yielding composites-Amber, Vijay, Jawahar, Kisan,
Sona, and Vikram-developed from these populations
were released for commercial production (table 7).
In addition to national breeding stocks, Indian
maize researchers have made considerable use of
germplasm from Colombia (ETO germplasm com-
plexes) and southeastern United States (North Caro-
lina and Florida) in developing inbred lines (IARI
1980). While dozens of hybrids have been released, the
area planted with hybrids remained stagnant at about
10% to 15% through the 1970s and early 1980s. This
situation has begun to change with the expansion of
private maize seed sector activities.As of 1986, some 10
private seed companies (transnational and national)
are engaged in maize improvement research and seed
production in India (Pray 1986). These private sector
hybrids are grown on about 10% of the total maize
area.
Indian maize researchers participate in CIMMYT's
International Maize Testing Program. Perhaps CIM-
MYT's biggest contribution has been in providing


subtropical germplasm for maize varieties and hybrids
adapted to production during the winter (Rabi) season
(personal communication, R.L. Paliwal). For example,
a family of Tuxpefio-1 (Pop. 21) is the female parent in
the hybrid, Pathari Makka. India has also released an
open-pollinated variety, Lakshami, based on CIM-
MYT material (Sids 7444, from Pop. 44) grown exten-
sively in Bihar State. A varietal hybrid, Sangam, uses
Tuxpefio Planta Baja (C7) as one parent. Finally,
J115-"Parbhat," is based on Suwan 1 from Thailand.
Since 1985, IITA has also supplied its inbred lines and
hybrids for testing in India.

NEPAL
Maize is the second most important cereal pro-
duced in Nepal after rice. During 1983-85, approxi-
mately 784,000 t of grain were produced annually, with
national yields averaging 1.5 t/ha.
The Nepalese National Maize Development Pro-
gram (NMDP) receives a broad range of germplasm
from CIMMYT (Sharma and Anderson 1985). Most
farmers grow open-pollinated varieties, though a few
farmers in the south grow Indian hybrids. Three
open-pollinated varieties have been released from
CIMMYT materials after local selection for better
adaptation to Nepalese farming:
1. Janaki (white): (Rampur 7434; Pop. 34)
2. Arun-2 (yellow): (UNCAC x Phil DMR; Pop. 59)
3. Makalu-2 (yellow): (Amarillo del Bajio; Pop. 45)
Of these OPVs, Janaki and Arun-2 have been the
most popular with farmers (Sharma and Anderson
1985).









IMPROVED MAIZE VARIETIES AND HYBRIDS


Table 8. Open-pollinated varieties released in Pakistan, 1970-85

Grain
Variety color Germplasm sources
Change White Swabi white (local) and U.S. inbred lines (WF9, M14, B37,
WM13R, HY, A619, Oh45)
Zia White (Early King x Payette) x Changez
Khyber White Akbar x Bowman's Cole Creek
Shaheen White Zia x (Nodak, Mandan, Payette)
Sadaf White White version of Neelum
Sarhad White White Akbar x Tropical x U.S. Corn Belt
Azam White Zia x Pirsabak 7930
Ehsan White Sarhad White x Pirsabak 7934
Neelum Yellow Local x Latin American x U.S. Corn Belt materials
Agaiti-72 Yellow Six-way cross (M14 x Pa32) x (WF9 x W9) x (A495 x A556)
Akbar Yellow Neelum x U.S. Corn Belt materials
Sharhad Yellow Yellow Yellow version of Sarhad
Sultan Yellow Akbar x (Syn 548, Syn 547, Neluum and Comp. II)
Sunheri Yellow Agaiti-72 x Amarillo Cristalino-2
Kashmir Gold Yellow Yousafwala 7845 (Pop.45, Amarillo Bajio)

Source: National Coordinated Maize Programme, Pakistan Agricultural Research Council.


PAKISTAN
Maize is the third most important cereal produced
in Pakistan, after wheat and rice. During 1983-85,
approximately 1.0 million t of grain were produced on
801,000 ha, with national yields averaging 1.3 t/ha.
Most of the maize area is irrigated, and the crop is
grown in the hot summer season under very difficult
climatic conditions.
Initial maize improvement work in Pakistan fo-
cused on hybrid development, relying primarily on
inbred lines and hybrids from the U.S. Corn Belt
supplied through USAID during the 1950s. In the mid-
1960s, the hybrid development work was discontinued
due to the lack of a viable seed industry to produce and
distribute hybrid seed. Emphasis was placed on devel-
oping open-pollinated varieties (synthetics, compos-
ites), largely based on temperate germplasm but with
some tropical germplasm introgressed for disease
resistance to leaf blights (H. turcicum and H. maydis)
and stalk rots caused by Fusarium spp. A number of
outstanding open-pollinated varieties have been devel-


oped, based primarily on U.S. temperate germplasm
and some tropical and subtropical materials from
CIMMYT (table 8).
CIMMYT and the National Coordinated Maize
Program of the Pakistan Agricultural Research Coun-
cil have had close collaborative research ties for two
decades. CIMMYT resident maize advisers have been
stationed in Pakistan since 1968, and considerable
amounts of CIMMYT germplasm are evaluated annu-
ally. Since 1985, national maize researchers have also
received IITA's white and yellow grain hybrid trials.
It is estimated that 30% to 40% of the farmers use
some kind of mixtures of local varieties and improved
genotypes. Among the most extensively grown are Zia,
Shaheen, Sarhad, Azam, Akbar, Neelum, and Sultan
(Chaudhry 1984). Three open-pollinated varieties based
on CIMMYT materials have been released in Paki-
stan: Azam, Ehsan, and Kashmir Gold (not officially
released but widely grown in the States ofAzad Jammu
and Kashmir).









RECENT RELEASES


tW^S .150 \ u
HWT 1 ^Wt .-. \rtt "

LAY oi .1 tW
M PL
ISDA


Figure 12. Maize trial conducted at the Maize and Millets Research Institute,
Punjab, Pakistan. Source: CIMMYT.


Provincial and federal maize research programs
have reactivated their hybrid development programs in
recent years (PARC/CIMMYT 1988). The primary
germplasm sources used in these hybrid programs are:
U.S. public inbred lines such as Mo 17, B-73, B-44,
A-619, Oh 43, Oh 45, and H-51; older local inbred lines
such as Punjab-7, and new inbred lines extracted from
national breeding populations and commercial varie-
ties.
The lack of a viable seed industry remains a major
constraint in the delivery of improved genotypes to
farmers. Only enough certified seed to plant 5% of the
total national maize area is produced annually. Most of
the certified seed is of open-pollinated varieties. Only
about 13,000 ha are planted with hybrid maize in
Pakistan. Most of this area is planted with hybrids
developed by Rafhan Maize Products, Ltd., a corn
starch company. Rafhan's hybrids are based on U.S.
inbred lines (M017, B73) as well as locally developed
inbreds with resistance to leaf blights and stalk rots
(personal communication, Khan Bajadur). Rafhan only


distributes its hybrids to contract growers who produce
grain for wet-milling.

SRI LANKA
Maize is the second most important cereal crop
(after rice) in Sri Lanka. It is produced on about 50,000
ha and is used mainly for animal feed. Over 90% of the
area is in the highlands and is irrigated. Maize breeding
objectives include resistance to stem borer (Chilo
partellus), stalk rots (Fusarium sp.), leaf blights (H.
turcicum), and sheath spots. Populations are being
formed using local materials and germplasm provided
by CIMMYT (personal communication, R.N. Wed-
derburn). One of the most promising populations,
Composite 6, is comprised of Thai composite, Cupu-
rico x flint compuesto, and Poza Rica 7425. Various
varieties from CIMMYT's populations 28, 29, 36, and
41 have also been introduced. Open-pollinated varie-
ties and nonconventional hybrids (varietal and family
crosses) are being developed. A yellow-grain variety
developed from Suwan 1 was released in 1977 under
the name of Bhadra 1.









IMPROVED MAIZE VARIETIES AND HYBRIDS


Southeast Asia and Pacific

INDONESIA
Maize is the second most important cereal pro-
duced in Indonesia, after rice. During 1983-85, ap-
proximately 5.2 million t of grain were produced annu-
ally on 2.6 million ha, with national yields averaging 2.0
t/ha. Average maize yields have been increasing in
Indonesia due to the rapid increase in the use of
fertilizer, especially nitrogen, which is being sold at
highly subsidized prices.
CIMMYT collaborates with the national maize
program and regularly supplies international testing
trials and makes staff visits to the country. More
recently, IITA has supplied inbred lines with combined
downy mildew and streak virus resistance to the na-
tional program and to a private seed company, P.T.
Bright.
The maize seed industry is not well developed and
only about 25% of the total maize area is planted with
improved varieties. In the future, it is envisioned that
both open-pollinated varieties and hybrids will have
market niches. Two government agencies-Perem Sang
Hyang Seri and P.T. Pertaini Patra Tani-produce
some certified maize seed of open-pollinated varieties.
In recent years, a number of private seed companies
have also been established. Three transnational
companies-P.T. Bright (division of Dekalb), Cargill,
and Pioneer Hi-Bred-have released downy mildew
resistant hybrids. Cargill's hybrid, C-1, is the most
popular, and the seed demand for this genotype has
outpaced supply (Timmer 1987). P.T. Bright is also
selling an open-pollinated variety, Arjuna, which is
derived from Suwan 2 developed at Kasertsart Univer-
sity in Thailand.

PHILIPPINES
Maize is the second most important cereal pro-
duced in the Philippines, after rice. During 1983-85,
approximately 3.3 million t of grain were produced
annually on 3.4 million ha, with national yields averag-
ing 1.0 t/ha. Most improved cultivars (yellow and
white) grown by farmers are open pollinated. Of the
approximately 3.4 million ha annually planted with
maize, only 1% of the total maize area is planted with
hybrids and about 25% is planted with improved
open-pollinated varieties.
Maize improvement research is conducted in the
public and private sectors. The Institute of Plant Breed-
ing (IPB) at the University of the Philippines, Los


Bafios, has participated in CIMMYT's international
variety testing program since the mid-1970s (personal
communication, M. Latin). IPB's maize breeding pro-
gram has been primarily geared toward the develop-
ment of superior open-pollinated varieties (compos-
ites). A modest hybrid breeding component of the
program was initiated in 1980, and inbred lines have
been extracted from several source populations. Some
hybrids are being used in limited areas covered by the
government's intensified maize production program.
Although CIMMYT has been a major source of
germplasm, most of its material has lacked resistance
to downy mildew, a major constraint to maize produc-
tion in the country. IPB has also participated in a
CIMMYT-coordinated project to improve several
populations for downy mildew resistance, using Philip-
pine and Thai source materials. They have tested
experimental varieties with tropical adaptation. In 1986,
IPB released its first variety based on CIMMYT
germplasm, IPB Variety 4, a white flint based on
Rampur 8075, derived from a downy mildew resistant
population developed specially through the collabora-
tive IPB-CIMMYT program. Since 1985, IITA has
supplied inbred lines and populations to IPB and two
private companies, the San Miguel Corp. and Pioneer
Hi-Bred International (personal communication, S.K.
Kim).
Currently four seed companies (one local and three
foreign) produce hybrid maize seed in the Philippines.
These companies produce hybrids that undergo an
accreditation process based on agronomic perform-
ance trials coordinated by the Philippines Seed Board.
Pioneer Hi-Bred has two downy mildew tolerant hy-
brids that are officially approved. Pioneer Hybrid 6181
is a yellow material released in 1980 and extensively
grown in Southeast Asia. Pioneer Hybrid 3228 was
released in 1985; it is better yielding than 6181 and has
better tolerance to downy mildew. Parent lines in 6181
were derived from Thai Composite #1, Thai Comp.
3-4F4, and Cupurico x Flint Composite DMR. Cargill
also has a downy mildew resistant hybrid released in
1983. The San Miguel Corporation has released two
varietal hybrids with downy mildew resistance: SMC-101
(EV from Pop. 28 x Suwan 1) and SMC-102 (EV from
Pop. 36 x Suwan 1).
Certified seed may be marketed either directly by
the company or through local marketing companies
and agricultural input suppliers. The open-pollinated
varieties are produced and marketed by a limited
number of small seed growers. These varieties do not
benefit from a good seed production and distribution









IMPROVED MAIZE VARIETIES AND HYBRIDS


Southeast Asia and Pacific

INDONESIA
Maize is the second most important cereal pro-
duced in Indonesia, after rice. During 1983-85, ap-
proximately 5.2 million t of grain were produced annu-
ally on 2.6 million ha, with national yields averaging 2.0
t/ha. Average maize yields have been increasing in
Indonesia due to the rapid increase in the use of
fertilizer, especially nitrogen, which is being sold at
highly subsidized prices.
CIMMYT collaborates with the national maize
program and regularly supplies international testing
trials and makes staff visits to the country. More
recently, IITA has supplied inbred lines with combined
downy mildew and streak virus resistance to the na-
tional program and to a private seed company, P.T.
Bright.
The maize seed industry is not well developed and
only about 25% of the total maize area is planted with
improved varieties. In the future, it is envisioned that
both open-pollinated varieties and hybrids will have
market niches. Two government agencies-Perem Sang
Hyang Seri and P.T. Pertaini Patra Tani-produce
some certified maize seed of open-pollinated varieties.
In recent years, a number of private seed companies
have also been established. Three transnational
companies-P.T. Bright (division of Dekalb), Cargill,
and Pioneer Hi-Bred-have released downy mildew
resistant hybrids. Cargill's hybrid, C-1, is the most
popular, and the seed demand for this genotype has
outpaced supply (Timmer 1987). P.T. Bright is also
selling an open-pollinated variety, Arjuna, which is
derived from Suwan 2 developed at Kasertsart Univer-
sity in Thailand.

PHILIPPINES
Maize is the second most important cereal pro-
duced in the Philippines, after rice. During 1983-85,
approximately 3.3 million t of grain were produced
annually on 3.4 million ha, with national yields averag-
ing 1.0 t/ha. Most improved cultivars (yellow and
white) grown by farmers are open pollinated. Of the
approximately 3.4 million ha annually planted with
maize, only 1% of the total maize area is planted with
hybrids and about 25% is planted with improved
open-pollinated varieties.
Maize improvement research is conducted in the
public and private sectors. The Institute of Plant Breed-
ing (IPB) at the University of the Philippines, Los


Bafios, has participated in CIMMYT's international
variety testing program since the mid-1970s (personal
communication, M. Latin). IPB's maize breeding pro-
gram has been primarily geared toward the develop-
ment of superior open-pollinated varieties (compos-
ites). A modest hybrid breeding component of the
program was initiated in 1980, and inbred lines have
been extracted from several source populations. Some
hybrids are being used in limited areas covered by the
government's intensified maize production program.
Although CIMMYT has been a major source of
germplasm, most of its material has lacked resistance
to downy mildew, a major constraint to maize produc-
tion in the country. IPB has also participated in a
CIMMYT-coordinated project to improve several
populations for downy mildew resistance, using Philip-
pine and Thai source materials. They have tested
experimental varieties with tropical adaptation. In 1986,
IPB released its first variety based on CIMMYT
germplasm, IPB Variety 4, a white flint based on
Rampur 8075, derived from a downy mildew resistant
population developed specially through the collabora-
tive IPB-CIMMYT program. Since 1985, IITA has
supplied inbred lines and populations to IPB and two
private companies, the San Miguel Corp. and Pioneer
Hi-Bred International (personal communication, S.K.
Kim).
Currently four seed companies (one local and three
foreign) produce hybrid maize seed in the Philippines.
These companies produce hybrids that undergo an
accreditation process based on agronomic perform-
ance trials coordinated by the Philippines Seed Board.
Pioneer Hi-Bred has two downy mildew tolerant hy-
brids that are officially approved. Pioneer Hybrid 6181
is a yellow material released in 1980 and extensively
grown in Southeast Asia. Pioneer Hybrid 3228 was
released in 1985; it is better yielding than 6181 and has
better tolerance to downy mildew. Parent lines in 6181
were derived from Thai Composite #1, Thai Comp.
3-4F4, and Cupurico x Flint Composite DMR. Cargill
also has a downy mildew resistant hybrid released in
1983. The San Miguel Corporation has released two
varietal hybrids with downy mildew resistance: SMC-101
(EV from Pop. 28 x Suwan 1) and SMC-102 (EV from
Pop. 36 x Suwan 1).
Certified seed may be marketed either directly by
the company or through local marketing companies
and agricultural input suppliers. The open-pollinated
varieties are produced and marketed by a limited
number of small seed growers. These varieties do not
benefit from a good seed production and distribution









IMPROVED MAIZE VARIETIES AND HYBRIDS


Southeast Asia and Pacific

INDONESIA
Maize is the second most important cereal pro-
duced in Indonesia, after rice. During 1983-85, ap-
proximately 5.2 million t of grain were produced annu-
ally on 2.6 million ha, with national yields averaging 2.0
t/ha. Average maize yields have been increasing in
Indonesia due to the rapid increase in the use of
fertilizer, especially nitrogen, which is being sold at
highly subsidized prices.
CIMMYT collaborates with the national maize
program and regularly supplies international testing
trials and makes staff visits to the country. More
recently, IITA has supplied inbred lines with combined
downy mildew and streak virus resistance to the na-
tional program and to a private seed company, P.T.
Bright.
The maize seed industry is not well developed and
only about 25% of the total maize area is planted with
improved varieties. In the future, it is envisioned that
both open-pollinated varieties and hybrids will have
market niches. Two government agencies-Perem Sang
Hyang Seri and P.T. Pertaini Patra Tani-produce
some certified maize seed of open-pollinated varieties.
In recent years, a number of private seed companies
have also been established. Three transnational
companies-P.T. Bright (division of Dekalb), Cargill,
and Pioneer Hi-Bred-have released downy mildew
resistant hybrids. Cargill's hybrid, C-1, is the most
popular, and the seed demand for this genotype has
outpaced supply (Timmer 1987). P.T. Bright is also
selling an open-pollinated variety, Arjuna, which is
derived from Suwan 2 developed at Kasertsart Univer-
sity in Thailand.

PHILIPPINES
Maize is the second most important cereal pro-
duced in the Philippines, after rice. During 1983-85,
approximately 3.3 million t of grain were produced
annually on 3.4 million ha, with national yields averag-
ing 1.0 t/ha. Most improved cultivars (yellow and
white) grown by farmers are open pollinated. Of the
approximately 3.4 million ha annually planted with
maize, only 1% of the total maize area is planted with
hybrids and about 25% is planted with improved
open-pollinated varieties.
Maize improvement research is conducted in the
public and private sectors. The Institute of Plant Breed-
ing (IPB) at the University of the Philippines, Los


Bafios, has participated in CIMMYT's international
variety testing program since the mid-1970s (personal
communication, M. Latin). IPB's maize breeding pro-
gram has been primarily geared toward the develop-
ment of superior open-pollinated varieties (compos-
ites). A modest hybrid breeding component of the
program was initiated in 1980, and inbred lines have
been extracted from several source populations. Some
hybrids are being used in limited areas covered by the
government's intensified maize production program.
Although CIMMYT has been a major source of
germplasm, most of its material has lacked resistance
to downy mildew, a major constraint to maize produc-
tion in the country. IPB has also participated in a
CIMMYT-coordinated project to improve several
populations for downy mildew resistance, using Philip-
pine and Thai source materials. They have tested
experimental varieties with tropical adaptation. In 1986,
IPB released its first variety based on CIMMYT
germplasm, IPB Variety 4, a white flint based on
Rampur 8075, derived from a downy mildew resistant
population developed specially through the collabora-
tive IPB-CIMMYT program. Since 1985, IITA has
supplied inbred lines and populations to IPB and two
private companies, the San Miguel Corp. and Pioneer
Hi-Bred International (personal communication, S.K.
Kim).
Currently four seed companies (one local and three
foreign) produce hybrid maize seed in the Philippines.
These companies produce hybrids that undergo an
accreditation process based on agronomic perform-
ance trials coordinated by the Philippines Seed Board.
Pioneer Hi-Bred has two downy mildew tolerant hy-
brids that are officially approved. Pioneer Hybrid 6181
is a yellow material released in 1980 and extensively
grown in Southeast Asia. Pioneer Hybrid 3228 was
released in 1985; it is better yielding than 6181 and has
better tolerance to downy mildew. Parent lines in 6181
were derived from Thai Composite #1, Thai Comp.
3-4F4, and Cupurico x Flint Composite DMR. Cargill
also has a downy mildew resistant hybrid released in
1983. The San Miguel Corporation has released two
varietal hybrids with downy mildew resistance: SMC-101
(EV from Pop. 28 x Suwan 1) and SMC-102 (EV from
Pop. 36 x Suwan 1).
Certified seed may be marketed either directly by
the company or through local marketing companies
and agricultural input suppliers. The open-pollinated
varieties are produced and marketed by a limited
number of small seed growers. These varieties do not
benefit from a good seed production and distribution









RECENT RELEASES


Figure 13. Drs. Rachain Thiraporn, manager of Suwan Farm of Kasetsart University in Thailand, and Richard N.
Wedderburn, a CIMMYT entomologist stationed in Thailand, view a test plot of corn. Much of the research on
corn improvement in Thailand has been carried out at Suwan Farm. Source: CIMMYT.


system, and hence the rate of spread has been slow.

THAILAND
Maize is the second most important cereal grain
produced in Thailand, and the country is a net maize
exporter of more than 2 million t annually. During
1983-85, approximately 4.2 million t of grain were
produced annually on 1.7 million ha, with national
yields averaging 2.4 t/ha.
The Thailand National Maize Program has coop-
erated with CIMMYT since the mid-1960s and with
various Rockefeller Foundation-supported collabora-
tive maize research programs in Asia and in other
continents. The CIMMYT international trials have
been tested extensively in Thailand but have lacked
suitable resistance to downy mildew. More recently,
IITA has supplied its inbred lines and hybrids to public


and private sector organizations in Thailand. Although
CIMMYT and IITA materials have been used in form-
ing new populations and in extracting inbred lines, no
direct releases have been made from these materials.
The history of the development of Suwan 1 is th(
epitome of what international cooperation in germplasnr
development can achieve and has achieved. The stor3
starts with the introduction in 1960 of the variety3
Tiquisate Golden Yellow (a mixture of two strains of
maize of Cuban origin-a white semident and a golden
yellow flint) from Guatemala. This variety was well
adapted to Thailand and had a golden yellow semi-flint
grain that was well regarded in international markets.
Farmers took up this variety, and the maize area in
Thailand began to increase rapidly.
Based on the adaptation of Tiquisate Golden Yel-
low in Thailand, the national program requested anc










IMPROVED MAIZE VARIETIES AND HYBRIDS

Table 9. Germplasm assembled in Thai Composite #1


Source Group Material


Caribbean Islands


Cuba Gr.1
Cuba 11J
Puerto Rico Gr.1
Cuba 40
Cuba 1J
Cuba V59
Antigua Gr.1
Antigua Gr.2
Puerto Rico Gr.2
Barbados Gr.1
Cupurico
Caribb. Flint Comp.
Comp. Caribb. Amarillo
Tiquisate Golden Yellow x Caribb.
Comp.
Tiquisate Golden Yellow x Guadalupe
12D-14D


Argentino
Argentino
Argentino
Tuson
Tuson-Carilla-Criollo-Tuson
Tuson-Carilla-Criollo-Tuson
Tuson-Carilla-Criollo-Tuson
Tuson-Carilla-Criollo-Tuson
Tuson-Carilla-Criollo-Tuson
Tuson-Carilla-Criollo-Tuson
Tuson-Carilla-Criollo-Tuson
Tuson-Carilla-Criollo-Tuson
Tuson-Carilla-Criollo-Tuson
Tuson-Carilla-Criollo-Tuson

Tuson-Carilla-Criollo-Tuson



Tuxpefio
Tuxpefio
Tuxpefio
Tuxpefio
Salvadorefio
Argentino-Criollo

Northern Catato
Cuban Yellow Dent
Cuban Yellow Dent
Argentino-Criollo-Tuson
Argentino-Criollo-Tuson

Caribbean-Tuxpeiio-India-U.SA.
Caribbean-Tuxpefo-India-U.SA.
Caribbean-Tuxpefio-India-U.SA.
Caribbean-Tuxpefio-India-U.SA.
Caribbean-Tuxpeiio-India-U.SA.

Tuxpefio-Caribbean-U.SA.
Tuxpefio-Caribbean-U.SA.
Tuxpeiio-Caribbean-U.SA.
Tuxpefio-Caribbean-U.SA.


Source: Sujin Jinahyon (1973)


Veracruz 163
Veracruz 181
Veracruz Gr.48
Tamaulipas 8
Salvadorefio Amarillo
Tiquisate Golden Yellow

Guayana Francesca III
Bahia III BCO
Dentado Amarillo
Narifio 330-Peru 330
DV 103

Composite Al
Multiple Cross 2
Multiple Cross 4
Synthetic A3B
Synthetic All

Tuxpantigua
Veracruz 181 x Antigua Gr.2
USantigua
Florida Synthetic


Mexico and
Central America






South America


India


Other









RECENT RELEASES


received other tropical varieties and collections of
Caribbean origin from the Mexican-Rockefeller Foun-
dation program in Mexico. This germplasm develop-
ment process was accelerated in 1966 with the shifting
from India to Thailand of the Rockefeller
Foundation-supported Inter-Asian Corn Program and
the establishment of CIMMYT; both programs played
an active role in the formulation of new national
breeding materials.
In 1967, the Thai national program chose 36
germplasm complexes to form Thai Composite #1.
General yield performance, adaptation in Thailand,
and diversity of material by origin were the major
criteria used in the selection of these germplasms
(table 9).
A modified ear-to-row scheme was employed to
systematically inter-mate all germplasm sources. In
1970, four cycles of selection were completed, and the
composite was then officially named Thai Composite
#1. By 1973, using S1 progeny selection followed by
recombination, three cycles of selection had been
completed. In addition, 250 S1 families were chosen
during cycle 3 selection to form the sub-population
Thai Composite #1 Early, which eventually became
Suwan 2.
While Thai Composite #1 was 20% to 30% higher
yielding than Tiquisate Golden Yellow, it faced a new
problem by the time it was theoretically ready for
release. Downy mildew, first reported in 1968, had
spread rapidly across the maize growing areas of Thai-
land. Thai Composite #1, as were other Thai materi-
als, was susceptible to downy mildew.
Stopgap measures were taken in 1973, and two
varieties with some resistance to downy mildew, Bogor
Synthetic 2 and Tainan 10, were imported for use by
Thai farmers. Simultaneously, several sources of downy
mildew resistance found in Philippine germplasm, DMR
1 and DMR 5, were backcrossed three times to the
Thai Composite #1 in 1972 and 1973 (personal com-
munication, B.L. Renfro).
The new material, called Thai Composite #1 DMR,
combined high yield potential with the needed resis-
tance to downy mildew; this was named Suwan 1 and
released in Thailand in 1974. Since then, Suwan 1 has
spread quickly to farmers' fields in Thailand, where it
is still the major variety grown by farmers. It has also
been released in some 20 countries of Asia, Latin
America, and Africa (personal communication, B.L.
Renfro).
Suwan 1 has also been used extensively by private
plant breeding companies in hybrid development. This


high-yielding, downy mildew resistant material has
been crossed with elite inbred lines from the United
States, Brazil, the Philippines, and elsewhere to pro-
duce excellent hybrids and varieties for tropical envi-
ronments. Cargill released an open-pollinated variety
in 1985, Cargill 357, based on Suwan 1 and South
American germplasm. Pioneer Hi-Bred has released
the Hybrid 3228, developed in the Philippines. Kaset-
sart University has also released a single-cross hybrid
and a three-way cross hybrid based on the Suwan 1
germplasm complex.
Improved maize seed is produced by the Depart-
ment of Agricultural Extension, Ministry of Agricul-
ture and Cooperatives, and by several private seed
companies. During 1984-85, it was expected that be-
tween 10,000 t and 13,000 t of certified maize seed of
open-pollinated maize varieties would be produced.
Hybrid seed production has been increasing very rap-
idly. In 1985, about 2,500 t was produced, compared to
30 t in 1981 (Pray 1987).

VIETNAM
Maize is the second most important cereal pro-
duced in Vietnam. During 1983-85, approximately 500,000
t of grain were produced annually on 387,000 ha, with
national yields averaging 1.3 t/ha.
CIMMYT supplies germplasm to the Vietnamese
national maize program and two open-pollinated va-
rieties based on these materials have been released:
VM-1 (C7 of Tuxpefio-1, Pop. 21) and MSB-49 (Pop.
49). Also, Suwan-2 has been released as TSB-2 and the
Ganga 5 Composite as Ganga 5. In 1985, it was esti-
mated that 80,000 hain northern Vietnam were planted
with VM-1 (personal communication, B.L. Renfro). A
quality protein maize variety, Population 63, has been
released (NRC 1988). MSB-31 (originally Suwan
8331) is under increase and has been approved for
release.

East Asia

CHINA
Maize is the third most important cereal grain in
China, after rice and wheat, and China is the leading
maize producer in the Third World. During 1983-85,
approximately 68 million t of grain were produced
annually on 18.4 million ha, with national yields averag-
ing 3.7 t/ha.
Nearly two-thirds of China's maize area is temper-
ate in environment with the remaining area
subtropical-to-tropical inits growing environment. The









RECENT RELEASES


received other tropical varieties and collections of
Caribbean origin from the Mexican-Rockefeller Foun-
dation program in Mexico. This germplasm develop-
ment process was accelerated in 1966 with the shifting
from India to Thailand of the Rockefeller
Foundation-supported Inter-Asian Corn Program and
the establishment of CIMMYT; both programs played
an active role in the formulation of new national
breeding materials.
In 1967, the Thai national program chose 36
germplasm complexes to form Thai Composite #1.
General yield performance, adaptation in Thailand,
and diversity of material by origin were the major
criteria used in the selection of these germplasms
(table 9).
A modified ear-to-row scheme was employed to
systematically inter-mate all germplasm sources. In
1970, four cycles of selection were completed, and the
composite was then officially named Thai Composite
#1. By 1973, using S1 progeny selection followed by
recombination, three cycles of selection had been
completed. In addition, 250 S1 families were chosen
during cycle 3 selection to form the sub-population
Thai Composite #1 Early, which eventually became
Suwan 2.
While Thai Composite #1 was 20% to 30% higher
yielding than Tiquisate Golden Yellow, it faced a new
problem by the time it was theoretically ready for
release. Downy mildew, first reported in 1968, had
spread rapidly across the maize growing areas of Thai-
land. Thai Composite #1, as were other Thai materi-
als, was susceptible to downy mildew.
Stopgap measures were taken in 1973, and two
varieties with some resistance to downy mildew, Bogor
Synthetic 2 and Tainan 10, were imported for use by
Thai farmers. Simultaneously, several sources of downy
mildew resistance found in Philippine germplasm, DMR
1 and DMR 5, were backcrossed three times to the
Thai Composite #1 in 1972 and 1973 (personal com-
munication, B.L. Renfro).
The new material, called Thai Composite #1 DMR,
combined high yield potential with the needed resis-
tance to downy mildew; this was named Suwan 1 and
released in Thailand in 1974. Since then, Suwan 1 has
spread quickly to farmers' fields in Thailand, where it
is still the major variety grown by farmers. It has also
been released in some 20 countries of Asia, Latin
America, and Africa (personal communication, B.L.
Renfro).
Suwan 1 has also been used extensively by private
plant breeding companies in hybrid development. This


high-yielding, downy mildew resistant material has
been crossed with elite inbred lines from the United
States, Brazil, the Philippines, and elsewhere to pro-
duce excellent hybrids and varieties for tropical envi-
ronments. Cargill released an open-pollinated variety
in 1985, Cargill 357, based on Suwan 1 and South
American germplasm. Pioneer Hi-Bred has released
the Hybrid 3228, developed in the Philippines. Kaset-
sart University has also released a single-cross hybrid
and a three-way cross hybrid based on the Suwan 1
germplasm complex.
Improved maize seed is produced by the Depart-
ment of Agricultural Extension, Ministry of Agricul-
ture and Cooperatives, and by several private seed
companies. During 1984-85, it was expected that be-
tween 10,000 t and 13,000 t of certified maize seed of
open-pollinated maize varieties would be produced.
Hybrid seed production has been increasing very rap-
idly. In 1985, about 2,500 t was produced, compared to
30 t in 1981 (Pray 1987).

VIETNAM
Maize is the second most important cereal pro-
duced in Vietnam. During 1983-85, approximately 500,000
t of grain were produced annually on 387,000 ha, with
national yields averaging 1.3 t/ha.
CIMMYT supplies germplasm to the Vietnamese
national maize program and two open-pollinated va-
rieties based on these materials have been released:
VM-1 (C7 of Tuxpefio-1, Pop. 21) and MSB-49 (Pop.
49). Also, Suwan-2 has been released as TSB-2 and the
Ganga 5 Composite as Ganga 5. In 1985, it was esti-
mated that 80,000 hain northern Vietnam were planted
with VM-1 (personal communication, B.L. Renfro). A
quality protein maize variety, Population 63, has been
released (NRC 1988). MSB-31 (originally Suwan
8331) is under increase and has been approved for
release.

East Asia

CHINA
Maize is the third most important cereal grain in
China, after rice and wheat, and China is the leading
maize producer in the Third World. During 1983-85,
approximately 68 million t of grain were produced
annually on 18.4 million ha, with national yields averag-
ing 3.7 t/ha.
Nearly two-thirds of China's maize area is temper-
ate in environment with the remaining area
subtropical-to-tropical inits growing environment. The









RECENT RELEASES


received other tropical varieties and collections of
Caribbean origin from the Mexican-Rockefeller Foun-
dation program in Mexico. This germplasm develop-
ment process was accelerated in 1966 with the shifting
from India to Thailand of the Rockefeller
Foundation-supported Inter-Asian Corn Program and
the establishment of CIMMYT; both programs played
an active role in the formulation of new national
breeding materials.
In 1967, the Thai national program chose 36
germplasm complexes to form Thai Composite #1.
General yield performance, adaptation in Thailand,
and diversity of material by origin were the major
criteria used in the selection of these germplasms
(table 9).
A modified ear-to-row scheme was employed to
systematically inter-mate all germplasm sources. In
1970, four cycles of selection were completed, and the
composite was then officially named Thai Composite
#1. By 1973, using S1 progeny selection followed by
recombination, three cycles of selection had been
completed. In addition, 250 S1 families were chosen
during cycle 3 selection to form the sub-population
Thai Composite #1 Early, which eventually became
Suwan 2.
While Thai Composite #1 was 20% to 30% higher
yielding than Tiquisate Golden Yellow, it faced a new
problem by the time it was theoretically ready for
release. Downy mildew, first reported in 1968, had
spread rapidly across the maize growing areas of Thai-
land. Thai Composite #1, as were other Thai materi-
als, was susceptible to downy mildew.
Stopgap measures were taken in 1973, and two
varieties with some resistance to downy mildew, Bogor
Synthetic 2 and Tainan 10, were imported for use by
Thai farmers. Simultaneously, several sources of downy
mildew resistance found in Philippine germplasm, DMR
1 and DMR 5, were backcrossed three times to the
Thai Composite #1 in 1972 and 1973 (personal com-
munication, B.L. Renfro).
The new material, called Thai Composite #1 DMR,
combined high yield potential with the needed resis-
tance to downy mildew; this was named Suwan 1 and
released in Thailand in 1974. Since then, Suwan 1 has
spread quickly to farmers' fields in Thailand, where it
is still the major variety grown by farmers. It has also
been released in some 20 countries of Asia, Latin
America, and Africa (personal communication, B.L.
Renfro).
Suwan 1 has also been used extensively by private
plant breeding companies in hybrid development. This


high-yielding, downy mildew resistant material has
been crossed with elite inbred lines from the United
States, Brazil, the Philippines, and elsewhere to pro-
duce excellent hybrids and varieties for tropical envi-
ronments. Cargill released an open-pollinated variety
in 1985, Cargill 357, based on Suwan 1 and South
American germplasm. Pioneer Hi-Bred has released
the Hybrid 3228, developed in the Philippines. Kaset-
sart University has also released a single-cross hybrid
and a three-way cross hybrid based on the Suwan 1
germplasm complex.
Improved maize seed is produced by the Depart-
ment of Agricultural Extension, Ministry of Agricul-
ture and Cooperatives, and by several private seed
companies. During 1984-85, it was expected that be-
tween 10,000 t and 13,000 t of certified maize seed of
open-pollinated maize varieties would be produced.
Hybrid seed production has been increasing very rap-
idly. In 1985, about 2,500 t was produced, compared to
30 t in 1981 (Pray 1987).

VIETNAM
Maize is the second most important cereal pro-
duced in Vietnam. During 1983-85, approximately 500,000
t of grain were produced annually on 387,000 ha, with
national yields averaging 1.3 t/ha.
CIMMYT supplies germplasm to the Vietnamese
national maize program and two open-pollinated va-
rieties based on these materials have been released:
VM-1 (C7 of Tuxpefio-1, Pop. 21) and MSB-49 (Pop.
49). Also, Suwan-2 has been released as TSB-2 and the
Ganga 5 Composite as Ganga 5. In 1985, it was esti-
mated that 80,000 hain northern Vietnam were planted
with VM-1 (personal communication, B.L. Renfro). A
quality protein maize variety, Population 63, has been
released (NRC 1988). MSB-31 (originally Suwan
8331) is under increase and has been approved for
release.

East Asia

CHINA
Maize is the third most important cereal grain in
China, after rice and wheat, and China is the leading
maize producer in the Third World. During 1983-85,
approximately 68 million t of grain were produced
annually on 18.4 million ha, with national yields averag-
ing 3.7 t/ha.
Nearly two-thirds of China's maize area is temper-
ate in environment with the remaining area
subtropical-to-tropical inits growing environment. The




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