Effects of sowing dates on grain yield and yield attributes of sorghum (Sorghum bicolor Moench) cultivar ICSV111 (Kapaala) in northern Ghana

Lack of a suitable sowing date has often been identified as the main constraint to sorghum (Sorghum bicolor Moench) cv. ICSV111 (Kapaala) production in Ghana. Field experiments were, therefore, used on-station at the Manga Agricultural Research Station to evaluate the effects of five sowing dates on yield and yield components of ‘Kapaala\' in northern Ghana. Sowing dates significantly (

Expanding supply of improved seed to farmers in northern Ghana to increase food security

The global problem of food security is particularly acute in many parts of west Africa, where food production needs to increase to meet growing demand. The ‘Green Revolution', where improved crop varieties are matched with improved management practices (particularly fertilisers), has been very successful in increasing food production in many parts of the world. However, in much of west Africa farmers have not adopted improved crop varieties. There are many reasons behind this lack of implementation, such as access to finance, access to improved varieties, access to market and government policy constraints. One major roadblock to adoption of improved varieties identified in Savelugu, northern Ghana, was a lack of sufficient improved cowpea seed (an important cash crop). In northern Ghana there are very few certified seed producers, mainly due to the highly regulated certification process. More than 90% of seed is traded between farmers in an ‘informal' seed market. In trials conducted in the Savelugu region improved, certified, cowpea varieties consistently outperformed farmer varieties and at field days farmers showed a strong preference for improved varieties.In the Savelugu region we worked with an Innovation Platform on a pilot system where one seed producer contracted ‘out‐growers' to produce certified seed, while the seed producer performed the certification processes and provide the required inputs and technical support. These out‐growers were situated in villages around Savelugu, where they were able to use the informal supply chain to deliver 20 additional tonnes of certified seed to farmers in the first year of operation

Sorghum head-bugs and grain molds in West and Central Africa: I. Host plant resistance and bug–mold interactions on sorghum grains

A regional sorghum head-bug and grain mold resistance trial was conducted in 1996 and 1997 at 15 and 13 research stations located in 10 West and Central African countries, respectively. Two cultivars namely IS 14384 and CGM 39/17-2-2 exhibited consistently high levels of resistance both to head-bugs and grain molds over years and localities. Eurystylus oldi was the dominant head-bug species at all localities except in Benin, Chad and Guinea. Sorghum grain mycoflora varied little between sites with genera Phoma and Fusarium dominating, followed by Curvularia. Efficiency of the insecticidal treatment on head-bug incidence partially confirmed the critical role played by head-bugs in aggravating mold infectio

Efficacy of a cry1Ab Gene for Control of Maruca vitrata (Lepidoptera: Crambidae) in Cowpea (Fabales: Fabaceae)

Cowpea [Vigna unguiculata (L) Walp.] is an important staple legume in the diet of many households in sub-Saharan Africa. Its production, however, is negatively impacted by many insect pests including bean pod borer, Maruca vitrata F., which can cause 20–80% yield loss. Several genetically engineered cowpea events that contain a cry1Ab gene from Bacillus thuringiensis (Bt) for resistance against M. vitrata were evaluated in Nigeria, Burkina Faso, and Ghana (West Africa), where cowpea is commonly grown. As part of the regulatory safety package, these efficacy data were developed and evaluated by in-country scientists. The Bt-cowpea lines were planted in confined field trials under Insect-proof netting and artificially infested with up to 500 M. vitrata larvae per plant during bud formation and flowering periods. Bt-cowpea lines provided nearly complete pod and seed protection and in most cases resulted in significantly increased seed yield over non-Bt control lines. An integrated pest management strategy that includes use of Bt-cowpea augmented with minimal insecticide treatment for protection against other insects is recommended to control pod borer to enhance cowpea production. The insect resistance management plan is based on the high-dose refuge strategy where non-Btcowpea and natural refuges are expected to provide M. vitrata susceptible to Cry1Ab protein. In addition, there will be a limited release of this product until a two-toxin cowpea pyramid is released. Other than South African genetically engineered crops, Bt-cowpea is the first genetically engineered food crop developed by the public sector and approved for release in sub-Saharan Africa

Genome resources for climate-resilient cowpea, an essential crop for food security.

Cowpea (Vigna unguiculata L. Walp.) is a legume crop that is resilient to hot and drought-prone climates, and a primary source of protein in sub-Saharan Africa and other parts of the developing world. However, genome resources for cowpea have lagged behind most other major crops. Here we describe foundational genome resources and their application to the analysis of germplasm currently in use in West African breeding programs. Resources developed from the African cultivar IT97K-499-35 include a whole-genome shotgun (WGS) assembly, a bacterial artificial chromosome (BAC) physical map, and assembled sequences from 4355 BACs. These resources and WGS sequences of an additional 36 diverse cowpea accessions supported the development of a genotyping assay for 51 128 SNPs, which was then applied to five bi-parental RIL populations to produce a consensus genetic map containing 37 372 SNPs. This genetic map enabled the anchoring of 100 Mb of WGS and 420 Mb of BAC sequences, an exploration of genetic diversity along each linkage group, and clarification of macrosynteny between cowpea and common bean. The SNP assay enabled a diversity analysis of materials from West African breeding programs. Two major subpopulations exist within those materials, one of which has significant parentage from South and East Africa and more diversity. There are genomic regions of high differentiation between subpopulations, one of which coincides with a cluster of nodulin genes. The new resources and knowledge help to define goals and accelerate the breeding of improved varieties to address food security issues related to limited-input small-holder farming and climate stress