Title: Research highlights
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00071929/00010
 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: VID00010
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. 2 No. 5 1985

Cameroon/University of Georgia/Chalfant

A New Look at the Importance of Cultivars
in Cowpea Research: Evidence from
Northern Cameroon
Moffi E. Ta'Ama, Ph.D.
Institute de la Recherche Agronomique
B. P. 33, Maroua, Cameroon

The Bean/Cowpea Collaborative Research
Support Program (CRSP), University of
Georgia/Cameroon project working with the
Cameroon National Institute of Agricultural
Research (IRA), has now completed three years
of research in Northern Cameroon. Our survey
reports show that high-input farmers have
successfully used improved cultivars which have
important resistance and produce high yields
with the required supporting practices. On the
other hand, 50 percent of the farmers in the area
are unable to use the new technology. The
abundance of local cowpea cultivars already
adapted to the region suggests merit in inven-
torying the local materials and embarking on
systematic studies to improve them as a way of
addressing this dilemma.

Local Cultivars and Local Checks
Local cultivar, as used here, refers to a
cultivar grown in an area by the inhabitants who
have empirical knowledge of the cultivar's adap-
tability and needed cultural practices. Widely
accepted as having originated in the Sahelian
belt of West Africa, diverse cowpea cultivars are
grown by local farmers from Senegal to Tchad.
They are largely photosensitive and are usual-
ly intercropped with cereals. In the extreme nor-
thern part of Cameroon where 78 percent of
farmers grow cowpeas, cultivars of these types
can be found. They fall into four main groups.

The first group is made up of cowpeas that set
flowers during the rainy season. The second
group is larger and is made up of truly photosen-
sitive indeterminate cowpeas referred to by
farmers as dry-season cultivars. These cultivars
are planted during the rainy season but do not
set pods until after the end of the rainy season,
which in the extreme north of Cameroon means
late September. They continue to produce pods
throughout October when other cereal crops
have dried up. Most of the recumbent cultivars
in the Mandara mountains belong to this group.
The third group is made up of truly dry-season
cowpeas grown on vertisols utilizing residual
moisture on river margins and along Lake Tchad.
All of these three groups are grown for both
grain and forage. The fourth group is made up
of determinate cultivars grown in regions on the
Nigerian border. These likely include releases
from Nigerian research grown for the Nigerian
market-the rough, brown-grain type. For
Cameroon, large white-seeded varieties are
generally preferred. Others of this fourth group
are unverified, extra-early locals said to mature
within two months.
Local cultivars in research have often been
seen as unproductive despite their adaptability
to the local environment. However, there are
data from this project, partially conducted in
collaboration with SAFGRAD (Semi-Arid Food
Grains Research and Development), which sug-
gest acceptable levels of productivity are
achieved when such environmentally adapted
local cultivars are used with relevant cultural

Funded Through USAID/BIFAD Grant No. AID/DSAN-XII-G-0261

The Choice of Local Checks
In the late 1970's, introduction of improved
cowpea cultivars in on-farm testing showed
higher yields but the findings failed to convince
farmers to grow them. In these tests, deter-
minate erect and medium-maturing improved
cultivars were compared with photosensitive, in-
determinate spreading cultivars. The latter were
at a disadvantage because the cultural practices
developed for the improved varieties were used
in the trials. There were similar findings in 1982
and 1983 in yield trials testing losses to insect
damage. Two local checks grown in randomized
complete blocks along with four improved
determinate medium-maturing cultivars yielded
lower even when protected (Bean/Cowpea CRSP
1982/83 Annual Reports). However, farmers
using the same local cultivars with no insec-
ticides produced yields which were apparently
higher than ours. One of the reasons was our
choice of the local check, Mogoda from the
Mandara Mountains, for our sites. It is suscep-
tible to virus disease. This, coupled with the
lower-than-usual rainfall in the Sahel areas at
that time, particularly affected the photosen-
sitive cultivars and resulted in almost no grain
yield. Similarly, when a cultivar grown mainly
on residual moisture around Lake Tchad (photo
2), was brought to Maroua (350 km south), it also
was found to be susceptible to virus during the
rainy season. However, this cultivar was known
to yield at least 1.5 tons grain yield without any
insecticide during the dry season around the

CRSP US Research Associate Dr. Moffi Ta'Ama and
veterinarian Mrs. Louisa Ta'Ama. Dr. Moffi Ta'Ama,
an employee of the University of Georgia, is
responsible for project field research in Cameroon
in collaboration with Cameroon IRA personnel.

It appears, therefore, that even within the sub-
region the adaptation of local cultivars to the
ecology of the area can be highly specific.
Following communication with the farmers, a
local cultivar, VYA, widely grown near
Moutourwa (60 km south of Maroua) was
selected as the local check. It belongs to our
first-defined group (farmers' rainy season
cowpea). Although it was less virus-susceptible
than the previously used local checks, its yield
was again significantly lower than the improved
cultivars when using the spacing and insecticide
protection previously used in our trials.

Yield Performance of Cowpea Cultivars on
Farmers' Fields and on Research Stations
In 1983 and 1984, after discussion with the
SAFGRAD agronomist, it was decided that on-
farm tests would be conducted giving particular
attention to the selection and management of
the local check. In subsequent trials, each
cultivar was planted at its own optimum den-
sity. Optimum density for the local in the test
was set in accord with the farmers' verbal in-
formation. Plant densities used in the study were
25,000 plants/ha for the local, VYA (photo 3);
50,000 plants/ha for the medium maturing im-
proved cultivar, TVX 3236-01G (photo 4); and
100,00 plants/ha for the sixty-day variety,
1T82E60 (not shown). These replicated trials,
with and without insecticide treatment, were
conducted in numerous locations in the extreme
north of the country with concurrent trials at
experiment stations.
Data from these tests at various locations
showed VYA to be an appropriate local check,
when protected by insecticides and following
farmers' recommended spacing. Under these

2. A highly interesting local cultivar grown on residual
moisture near Lake Tchad.

conditions VYA yields equal to the best high-
yielding cultivar, TVX 3236, but nearly double
that of 1T82E60, the sixty-day cultivar. These
data suggest that adapting an improved, but
perhaps alien, elite cultivar may not be the most
appropriate method of improving cowpea yield.
In the extreme northern areas of Cameroon,
research might well concentrate on improving
already-adapted local varieties using their
adapted cultural practices. These cultivars also
have other significant attributes important to

Other Important Attributes for
Cowpea Cultivars
Important cultivar attributes other than yield
were addressed in pre-extension variety trials in
1983 which included cowpea preference tests at
the farmers' level. Field-rated plant type, grain
size and color, grain soaking time, cooking time
and taste were recorded. Details of these tests
were reported in the 42-page SAFGRAD pre-
extension report for 1983.
Cowpea plant type is another very important
attribute in the Sahel subregion. Spreading viney

types are valued for forage in addition to grain
production. High ground cover with low plant
density is a positive attribute in a drought and
erratic-rainfall area. On the other hand, erect im-
proved varieties with synchronized maturity are
positive attributes in early determinate cowpeas.
Synchronized maturity supports cropping on a
calendar basis. Where rainfall is dependable,
these are desirable traits.
Under drought periods of two weeks during
the pre-extension trials, farmers noticed that the
determinate, upright, early, improved varieties
suffered more than TVX 3236 or VYA. After six
weeks, vegetative growth and pod-set ceased in
spite of the onset of rain showers. The indeter-
minate cultivars remained green under this
amount of drought, and subsequent casual rains
tended to stimulate the setting of new flowers
and pods. In addition, sometimes these latter
cultivars escaped insect attack due to the
decline in insect populations during this period
of drought and heat.
In a calendar-based cropping system,
synchronized maturity of the sixty-day variety
appears a positive attribute. This is not
necessarily positive when the onset of rain dic-
tates the farming operations. In Northern
Cameroon, a calendar-based system becomes a
new constraint to many farmers, dictating a rigid
harvesting date rather than supporting the flex-
ibility required by climatic conditions. In addi-
tion, in the extreme north, the preparation of the
nursery and transplanting of 'Mouskwari'
sorghum is a top-priority farm activity. This crop
is grown in dry season on vertisols, and is highly
valued. Even if other crops are overdried, rot-

J. LoCal V YA Moutourwa Iaentriec as nign yielcing in
regional trials.

4. Improved variety TVX 3236-01G from IITA, Ibadan, Nigeria.

5. Dr. Richard W. Chalfant, CRSP
Cameroon project Principal
Investigator, from the University of
Georgia. Project includes
collaboration with Boyce Thompson

ting or shattering in the field, they often must
wait for the sorghum transplanting. This fact can
negatively affect the yield of the sixty-day
cowpea. The non-synchronous maturity of VYA
is an advantage in such areas, enabling the
harvest of young green leaves and green pods
for human consumption and later dry pods at
convenient times fitting the farmers' cropping
There are significant and important ways that
the sixty-day varieties can fit into farming
systems.1 A recent finding by IITA suggests the
possibility of growing these varieties on residual
moisture of harvested paddy rice fields which
normally are barren after the rice is harvested.
There is a long tradition of residual moisture
agriculture in the country which may be further

In a region with short and unpredictable rain-
fall which imposes rigid cultural requirements,
cowpea improvement programs must respect
natural requirements as well as the preferences
of the farmers. Following visits to local villages
in northern Cameroon, we have identified VYA
lines which, when grown under proper condi-
tions such as a low plant population (25,000/ha),
compete favorably with the improved elite
varieties and produce acceptable yields of both
grain and forage. In addition, they have other

characteristics important to the farmer.
However, these local cultivars are quite site-
specific. Improved cultivars, such as those
developed at the International Institute of
Tropical Agriculture, have wider adaptability
but require more intense management, a pro-
blem for the subsistence farmers of northern
Cameroon. Emphasizing the locally adapted and
preferred cultivars, research programs can in-
corporate desirable traits from the improved
material with disease or insect resistance rather
than the other way around.
There is a need for systematic inventory of
the local cultivars, especially in the Mandara
mountains where a large number of wild cowpea
cultivars were observed by Dr. Hugh Bunting of
the University of Reading, leading a CRSP
External Review team in September, 1983. The
genetic potential there and in the areas around
Lake Tchad could be of great value to
Cameroon and to many other cowpea-growing
areas of the world. Major benefits can be ex-
pected from research such as that discussed
above. This project has focused on this goal.
'Hall, A. E. 1984. Developing Cowpea Varieties with
Improved Yield Under Conditions of Extreme Drought and
Heat. Bean/Cowpea CRSP Research Highlights, Vol. 1, No.
1, and,
de Mooy, C. J. 1985. Improving Cultural Practices and
Agricultural Implements for Cowpea Production in
Semiarid Botswana. Bean/Cowpea CRSP Research
Highlights, Vol. 2, No. 4.

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 MSU INT PRO ELSG

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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