A survey in Senegal and Guinea Conakry established the presence and incidence of cassava mosaic virus disease (CMD) in both countries. CMD occurred in all the fields surveyed, although its incidence was higher in Senegal (83%) than in Guinea (64%). Populations of the whitefly vector, Bemisia tabaci, were low in both countries averaging 1.7 adults per shoot in Guinea and 3.2 in Senegal. Most infections were attributed to the use of infected cuttings, 86 and 83% in Senegal and Guinea, respectively, ...

Imperata cylindrica (speargrass) is one of the most invasive weeds in the moist savannah zone of sub-saharan Africa. This study was conducted in 2001 and 2002 at Ijaye and Ilorin, Nigeria, to investigate the influence of four nicosulfuron doses (35, 70, 105, and 210 g a.i./ha) on the performance of maize, and its efficacy in the control of Imperata. The experiment was designed as a split-plot with three replications. Nicosulfuron was applied 2 weeks after planting maize. Hoe weeded and unweeded ...

The influence of some edaphic factors (soil moisture and organic matter) on plantain susceptibility to Radopholus similis was studied on cultivar Agbagba in a shade house. Densities of R. similis increased with increasing soil moisture level and were highest at field capacity revealing that at the peak of the rainy season, high densities could be expected under plantain cultivar Agbagba under field conditions. Slow drying out of soil strongly impaired root health. The implication of this is that ...

Irrigated rice cropping is practiced to reclaim alkaline-sodic soils in many parts of the world. This practice is in apparent contrast with earlier studies in the Sahel, which suggests that irrigated rice cropping may lead to the formation of alkaline-sodic soils. Soil column experiments were done with some of Sahel's most alkaline-sodic rice soils from the Office du Niger (Mali) and Foum Gleita (Mauritania). Soils were irrigated using non-saline carbonate-rich irrigation water typical for the ...

The banana weevil Cosmopolites sordidus (Germar) is an important pest on bananas and plantains (Musa spp.). Population build-up is slow and weevil problems become increasingly important in successive crop cycles (ratoons). Yield loss results from plant loss (death, snapping, toppling), mat disappearance (failure to sucker) and reduced bunch size. Damage assessment requires destructive sampling and is most often done on the corm periphery or corm cross sections of recently harvested plants. A wide ...

The West and Central Africa Collaborative Maize Research Network (WECAMAN) was instituted with the ultimate goal to help improve maize (Zea mays L.) production in West and Central Africa (WCA). One objective of the Network is to enhance the research capacity and capability of the participating national research systems (NARS). This objective is being achieved through training courses and workshops, monitoring tours, consultation visits and a visiting scientist program. The Network has conducted ...

In Uganda, banana (Musa spp) and coffee (Coffea spp) form the economic base for a big population of small-scale farmers and provide environmental protection. However, their production is currently declining. The two crops are grown in association as intercrops or adjacent monocultures but little information exists on biological and socio-economic complementarities and antagonisms between them; thus complicating interventions to reverse the decline. In view of the above, Participatory Rural Appraisals ...

The classification of maize inbred lines into heterotic groups is an important undertaking in hybrid breeding. The objectives of our research were to: (1) separate selected tropical mid-altitude maize inbred lines into heterotic groups based on grain yield data; (2) assess the genetic relationships among these inbred lines using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers; (3) examine the consistency between yield-based and marker-based groupings of the ...

The use of mutualistic fungal endophytes to control the banana weevil (Cosmopolites sordidus) and banana parasitic nematodes (Radopholus similis, Pratylenchus goodeyi and Helicotylenchus multicinctus) is currently being investigated at the International Institute of Tropical Agriculture. Fungal endophytes are microorganisms that colonize the plant through the root system and for a part or whole of their life cycle live symptomlessly within the plant. Such organisms in some instances have been known ...

Low soil fertility and pest pressure are two causes of the decline in banana (Musa AAA) production in central Uganda. Foliar analysis by the Diagnosis and Recommendation Integrated System (DRIS) pinpoints K and Mg as the most limiting nutrients. This study tested the effects of K and Mg additions on plant performance and weevil damage for 2.75 yr, at Buligwe in central Uganda and Muyogo in southwest Uganda. All treatments received 25 kg P ha–1 and 100 kg N ha–1 annually, while K and Mg were applied ...