Performance of commonly grown agroforestry woody species was assessed at two locations in southern Nigeria, on an Alfisol (Oxic Paleustalf) at Ibadan in the forest-savanna transition zone and on an Ultisol (Typic Paleudult) at Onne in the forest zone, with annual rainfall of 1280 and 2400 mm respectively. The improvement effect of the wood species on soil properties appeared to be more pronounced on the Alfisol than on the acidic and nutrient poor Ultisol. Cordia alliodora and Gmelina arborea ...

Bananas are monocots and members of the genus Musa, family Musaceae. They are the second largest fruit crop in the world with an annual production of about 65 million tons (INIBAP 1993). The export trade, involving just dessert bananas of the Cavendish subgroup, comprises only 10% of the total banana production. Ninety percent is locally consumed and grown in backyards and small fields. Triploids are more widely cultivated than diploids and tetraploid

Three insect groups, known from the literature, were confirmed to make up a seed pest complex in cowpea fields in Benin Republic (West Africa). Several species of heteropteran pod‐sucking bugs (PSBs), two lepidopteran species, namely Maruca testulalis (Geyer) and Cydia ptyehora (Meyrick) and the weevil Apion varium Wagner occurred throughout southern Benin. Field infestations of PSBs and M. testulalis were always present, whereas A. varium and C. ptyehora occurrence was sporadic. Seed damage ...

An in vitro growth system was used to determine the virulence of two samples of Striga gesnerioides from Zakpota in southern Benin. Cowpea variety B301, previously considered resistant to all races of S. gesnerioides, was susceptible to both samples of the parasite. Two other cowpea varieties, 58–57 and IT81D-994, were totally resistant. Resistance in 58–57 was associated with a hypersensitive necrosis of infected roots, whilst IT81D-994 supported production of small S. gesnerioides tubercles with ...

The starchy staples of cassava (tuberous roots) provides more than half the calories consumed by more than 200 million people in sub-Saharan Africa, and the leaves are often used as a vegetable providing protein, vitamins and minerals. The cyanogenic potential of cassava has often been cited as a causal factor of health problems, particularly in areas where cassava roots are not properly processed. Provision of improved genotypes with low cyanogenic potential would ameliorate these problems. ...

The use of ploidy manipulations in potato breeding has been successfully applied by breeders at the International Potato Center (CIP) as a tool for germplasm enhancement and for the introduction of desirable genes of wild species into the cultivated gene pool. This methodology consists in reducing the ploidy level using haploids (2n = 2x = 24) and increasing it through the utilization of 2n gametes. It takes advantage of working at the 2x level to develop genotypes which combine multiple pest/disease ...

Black sigatoka (Mycosphaerella fijiensis Morelet), an airborne fungal leaf-spot disease, is a major constraint to plantain and banana (Musa spp.) production world-wide. Gaining further knowledge of the genetics of host-plant resistance will enhance the development of resistant cultivars, which is considered to be the most appropriate means to achieve stable production. Genetic analysis was conducted on 101 euploid (2x, 3x and 4x) progenies, obtained from crossing two susceptible triploid plantain ...

Sesamia calamistis Hampson and Eldana saccharina Walker larvae were reared at 25°C on pieces of stem from five indigenous African grasses. All five, Andropogon sp., Panicum maximum Jacq., Pennisetum polystachion (L.) Schult., P. purpureum L. and Sorghum arundinaceum (Desv.) Stapf. have been reported as host plants for one or both species. Larval survival, larval and pupal period and pupal weight were recorded and compared to values of these parameters for larvae reared on stems of maize and on ...