Title: Research highlights
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00071929/00001
 Material Information
Title: Research highlights
Uniform Title: Research highlights (East Lansing, Mich.)
Physical Description: v. : ill. ; 28 cm.
Language: English
Creator: Bean/Cowpea Collaborative Research Support Program
Publisher: Michigan State University Bean/Cowpea CRSP
Place of Publication: East Lansing
Publication Date: 1984-
Subject: Beans -- Research -- Periodicals -- Africa   ( lcsh )
Beans -- Research -- Periodicals -- Latin America   ( lcsh )
Cowpea -- Research -- Periodicals -- Africa   ( lcsh )
Cowpea -- Research -- Periodicals -- Latin America   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
periodical   ( marcgt )
Statement of Responsibility: Michigan State University Bean/Cowpea CRSP.
Dates or Sequential Designation: Vol. 1, no. 1 (1984)-
General Note: Title from caption.
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: UF00071929
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 - 13864898

Full Text

Michigan State University Bean/Cowpea CRSP

Vol. I No. 1 1984

Ardeshir Ghaderi, Editor

Developing Cowpea Varieties with Improved
Yield Under Conditions of Extreme Drought and Heat
Senegal/University of California-Riverside/Hall

Drought has returned to the Sahel zone of
Africa with increased severity. In 1983, crops
were sown one month later than normal in
the densely populated semiarid zone of
Senegal due to the late arrival of the rains.
The total rainfall during the growing season
was the lowest ever recorded, and crop
yields were extremely small. For the previ-
ous year, rainfall was also much less than
average in semiarid Senegal. The Sahel zone
is close to the Sahara Desert, and in addition
to being dry, it is hot. In these hot, dry, and
harsh conditions, cowpea and various mil-
lets appear to be the only crops with the
ability to produce useful quantities of food
during dry years. In 1982 and 1983, farmers
in semiarid Senegal had to rely more heavily
on cowpeas because their other crops failed
to produce much food.
A Bean/Cowpea CRSP project conducted
by the Senegalese Institute for Agricultural
Research (ISRA) and the University of
California (UC Riverside and UC Davis) is
developing improved cowpea production
systems for this harsh environment. Over
the short period of three years, this project
has enabled ISRA and UC to develop a
cowpea research team which is working on
many critical aspects of cowpea production
systems. The University of California is pro-
viding the Senegalese members of the team
with cowpea strains having improved adap-
tation to drought and heat, technical advice,
and training opportunities. The ISRA scien-
tists are conducting the research in Senegal
needed to develop and evaluate new vari-

eties of cowpeas and improved management
Varieties with improved drought adapta-
tion will make an important contribution to
the development of improved cowpea pro-
duction systems for the harsh conditions of
northern Senegal. ISRA scientists have de-
termined that early-maturing cowpea varie-
ties would be useful in this region. Summer
conditions in California are ideal for select-
ing early cowpea strains that are insensitive
to day length.
Scientists at UCR crossed cowpeas from
Senegal and California and selected erect
strains having extreme earliness and excel-
lent seed quality. ISRA scientists have now
evaluated these strains in comparison with
local cowpeas. Performance trials conducted
in two locations in the semiarid zone of
Senegal over three years have demonstrated
that, even with low rainfall and an extremely
short growing season, the best early cow-
peas from UCR can produce moderately
high yields. In 1982 at Louga on dry, sandy
soil and with high moisture evaporation,
these cowpeas yielded 1,000 kg/ha during a
growing season of only 60 days with only 180
mm of rain. Forty-nine days after sowing, the
early UCR cowpeas had substantial numbers
of mature pods (plate 1), whereas Sahelian
cowpeas sown at the same time only had
just begun to produce pods (plate 2). During
the record drought of 1983 with rainfall of
only 130 mm, the best cowpeas from UCR
and UCD produced 50% more than the best
local cowpeas in the trials. In addition, these

Funded through USAIDIBIFAD Grant No, AID/DSAN-XII-G-0261

studies indicate that one of the prostrate
cowpeas from Senegal has the ability to pro-
duce excellent yields in dry years, providing
the growing season is not too short. Trials
are now being planned to test the best cow-
peas from Senegal and UC on farmers'
fields. We anticipate that farmers who plant
both types of cowpeas the prostrate cow-
peas from Senegal and the early erect ones
from UC will have a more stable food
supply in this harsh environment where rain-
fall is highly variable.
This project is cooperating with other or-
ganizations which receive financial support
from USAID. The ISRA scientists associated
with this CRSP project are testing cowpeas
from the International Institute for Tropical
Agriculture in Nigeria and have found that
some of their early strains may be useful in
the north of Senegal, whereas other insect-
resistant strains show considerable promise
for the wetter regions to the south. In addi-
tion, the project has provided advanced
cowpea strains to the USAID-funded West-
ern Sudan Agricultural Research Project.
Provisional data from yield tests in the Sudan
in 1983 under harsh conditions in a dry loca-
tion there indicated that the best strains
from ISRA and UCR produced seven times

Plate 1: Varietal test in 1982 at Louga, Senegal with early
UCR cowpeas shown 49 days after sowing.

more yield than the best local Sudanese
Longer-term research is being conducted
to develop cowpeas with greater drought re-
sistance. At UCR, a field method has been
developed to select cowpeas with more ex-
tensive roots under drought. Cowpea strains
have been discovered which have differ-
ences in rooting and moisture extraction
from the soil. Crosses have been made to
combine the desirable characteristics that
confer adaptation to drought, and the prog-
eny will be screened in California in the
summer of 1984. At UCD, cowpeas with dif-
ferent branching and fruiting patterns have
been developed. The extent to which they
incorporate carbohydrates into seed is being
evaluated because increased partitioning of
dry matter to seed should be a desirable
characteristic for dry environments. Cow-
peas selected by the research projects at
UCR and UCD will be made available to the
ISRA scientists for testing in Senegal the fol-
lowing year.
Substantial progress has been made in
solving what may be a major problem for
cowpeas in the tropics heat stress. Scien-
tists at UCR have demonstrated under con-

Plate 2: Varietal test in 1982 at Louga, Senegal with
Sahelian cowpeas at 49 days sown at the same
time as Plate #1.

trolled environment and field conditions
that the high night temperatures which often
occur in tropical areas, such as Senegal, can
cause cowpeas to have inadequate pollina-
tion, poor pod set, and low yields. Many of
the cowpeas from Africa, that we have
tested, cannot tolerate high temperatures at
flowering. Fortunately, we have discovered a
few African cowpeas which have substantial
heat tolerance. We are now incorporating
this desirable characteristic into varieties for
West Africa. Our Senegalese colleagues
chose the best Senegalese heat tolerant var-
ieties for use as parents, based upon their
yield trials. Scientists at UCR crossed them
with the other heat-tolerant cowpeas, and
the progeny were then screened under ex-
tremely hot field conditions during the
summer in Imperial Valley, California. Some
of the progeny had substantial heat toler-
ance as indicated by their ability to set pods
in extremely hot conditions (plate 3). Most
cowpeas set very few pods in these hot con-
ditions (plate 4). Seed of heat-tolerant selec-
tions was given to our Senegalese colleagues
at our last annual meeting. They will grow
them in Senegal in the summer of 1984,
evaluate their performance, and select those

Plate 3: Cowpea selected for heat tolerance growing
under extremely hot conditions at Imperial
Valley, California in 1982.

strains which are best adapted to farmer
conditions and requirements in Senegal. We
have analyzed temperature data from tropi-
cal countries in different parts of the world
and consider that improved heat tolerance
should improve cowpea yields in many areas
where cowpeas are grown, especially in
parts of West Africa and India.
The essence of this project is that African
scientists and farmers are working to solve
their own food production problems in col-
laboration with UC scientists in key areas.
The approach is to design modifications to
the existing systems used by farmers (such
as improved varieties with resistance to
drought and heat, and improved low-input
management methods) that can be adopted
by farmers and that do not require substan-
tial increases in supplies of credit, equip-
ment, or agricultural chemicals which are
difficult to obtain.
This project is located in one of the harsh-
est environments for agriculture on earth,
and for the majority of the farms water is not
available for irrigation. It will not be possible
to achieve the high yields possible with the
methods of the "Green Revolution" here.
However, even modest increases in cowpea
yields would have a major impact on the

Plate 4: Conventional heat sensitive cowpea growing
under the same hot conditions in Imperial Valley,
California as the plant in Plate #3.

standards of living of the many subsistence
farm families who depend on rainfed crop
production in hot, semiarid Africa.
A major advantage of working collabora-
tively with colleagues in countries such as
Senegal is that the work has more likelihood
of long-term continuation than projects
mainly conducted by US scientists. A disad-
vantage of this overall approach is that it
may require longer time. A critical mass of
national program scientists must receive
substantial professional training if the pro-
grams over the long term are to develop im-
proved technology that is specifically
adapted to the harsh conditions which con-
front African farmers throughout the region.
However, it should also be recognized that

long-term support for collaborative research
projects has additional benefits the es-
sence of true cooperation is that it can be
mutually beneficial. The cowpea germplasm
with heat tolerance obtained by this project
in Africa is now being used by scientists at
UCR to develop improved varieties for hot
regions of the US. The cowpeas with im-
proved partitioning of carbohydrate to seeds
being developed at UCD will be useful in
the US as well as Africa and elsewhere. Fi-
nally, it should be recognized that the im-
proved understanding among people that
can be gained from long-term collaborative
projects has substantial value, especially for
relations among the people of the US and the
turbulent continent of Africa.

For further information contact:
Bean/Cowpea CRSP
200 Center for International Programs
Michigan State University
East Lansing, Michigan 48824-1035

Telephone: (517) 355-4693
Telex: 810-251-0737

An international community of persons, institutions,
agencies and governments committed to collectively
strengthening health and nutrition in developing
countries by improving the availability
and utilization of beans and cowpeas

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