A Regional Coordinated Trial (RCT) is helping Cowpea Improvement Program in Ghana, thanks to Accelerated Varietal Improvement and Seed Delivery of Legumes and Cereals in Africa (AVISA) and Bayer projects in West Africa. The regional trials involve genetic materials contributed by various research institutes and cross learning experience gleaned from testing and demonstrations.
In Ghana, the Council for Scientific and Industrial Research-Savanna Agricultural Research Institute (CSIR-SARI) is evaluating 198 genotypes including checks contributed by five institutions from major cowpea producing countries in West Africa. The institute contributed its 20 best genotypes (11 early maturing lines and 9 medium maturing lines) to the trial. International Institute of Tropical Agriculture (IITA) and Institute for Agricultural Research (IAR) of Ahmadu Bello University (ABU) in Nigeria contributed 80 genotypes (40 early and 40 medium) and 23 genotypes (10 early and 13 medium) respectively. INERA in Burkina Faso contributed 33 genotypes (19 early and 14 medium), while IER in Mali contributed 28 genotypes (14 early and 14 medium) to the RCT.
Additionally, each participating institution provided a check variety. In Ghana, Kirkhouse Benga (an early maturing variety) and Padi-Tuya (a medium maturing variety) were used as check. Evaluations were done in three locations in each country. In Ghana, trials were conducted in Nyankpala (Guinea Savanna), Yendi (Guinea savanna) and Manga (Sudan Savanna) which fall within the mandate agroecologies of the CSIR-SARI.
The main objective of this field experiment, as explained by the SARI cowpea breeder Dr Tengey, is “to increase the genetic variability available to breeders through exchange of germplasm while using a commonly agreed experimental design and statistical analysis”.
“Best performing genotypes will be selected for further evaluations and release or incorporated into elite cultivars through crosses after the evaluations,” he said.
Increasing the number of generations of germplasm evaluated in a year can increase genetic gains from cowpea research. This is a forward looking goal of the CSIR-SARI cowpea research team. Owing to the Tropical Legumes III (TL III) Project, which ended this year, CSIR-SARI was able to produce and advance several segregating populations. The capacity of the team was further expanded with the advent of AVISA and Bayer projects. “We have been able to plant 100 genotypes, each coming from 20 populations (originating from 20 crosses),” Dr Tengey explained.
These populations have resistance to Aphids, flower bud thrips, Striga, and they display improved seed coat color, large seed size and yield among others. By using the single seed-descent approach these populations will be quickly advanced to F6 generation at which point phenotyping will be done under different stress conditions and selections made. Funds from the two projects have been used to support these trials.
To modernize infrastructure, the seed storage house of the cowpea improvement program of the CSIR-SARI has been renovated with support from Bayer project. The AVISA project is expected to extend electricity to the facility and provide refrigerators for cold storage. Dr Tengey is also expecting his institute to acquire four more polytanks for water storage and to be able to establish a rainwater harvesting system to store more water for dry season trials.
AVISA aims to modernize breeding programs and strengthen the seed production and delivery systems by accelerating genetic gain for target traits in cowpea to at least 1.5% annually. It also aims at deployment of a breeding decision and informatics support system for assessing reliable performance information of products and provide feedback for the development of data-driven product profiles.
The Bayer project being implemented since 2015 in Ghana by CSIR-SARI aims at increasing genetic gain of existing cowpea breeding lines and enhancing effectiveness of the cowpea-breeding program. It also seeks to increase the competitiveness of cowpea for enhancing income and nutrition security of smallholder farmers in the drylands of sub-Saharan Africa. The project specifically focuses on establishing a functional breeding program for identifying and prioritizing farmer preferred traits and, increasing and improving efficiency of breeding approaches using modern breeding methods for cultivar development.