This paper examines the diffusion and adoption of improved mangrove swamp rice varieties (MV's) in Guinea Bissau, using evidence from the Cumbidja River Basin, a major mangrove rice growing area of the country. The results of the study show that the adoption of MV's has been rapid and impressive in the Cumbidja zone. Diffusion of the MV's which started in 1983 with 13% of farmers, had reached 70% of farmers by 1993. A Logit model was used to quantify the factors that determine the observed adoption ...

We have developed a simple protocol to allow the production of transgenic banana plants. Foreign genes were delivered into embryogenic suspension cells using accelerated particles coated with DNA. Bombardment parameters were optimized for a modified particle gun resulting in high levels of transient expression of the β-glucuronidase gene in both banana and plantain cells. Bombarded banana cells were selected with hygromycin and regenerated into plants. Molecular and histochemical characterization ...

A multilocational evaluation trial comprising 18 Musa genotypes was carried out from 1991 to 1994 in three representative locations in the humid forest (Onne, Nigeria and M'Balmayo, Cameroon) and the Forest-savanna Transstion (Ibadan, Nigeria) Zones of West and Central Africa. The main objective was to evaluate the performance of improved Musa germplasm under different agro-ecological conditions, thereby assessing the genotypes-by-environment interaction (GxE) for specific traits and yield stability. ...

In order to introduce currently-available genes with agronomical value into banana, two genetic transformation protocols have been optimized. Firstly, regenerable protoplasts isolated from embryogenic cell suspensions of the cultivar Bluggoe have been used for the introduction of several chimaeric uidA gene constructs by electroporation. With the inclusion of polyethylene glycol and heat shock, the frequency of transiently expressing protoplasts reached 1.8% as shown by an in situ β-glucuronidase ...

Plantains (Musa spp., AAB group) are an important food crop and an integral component of the farming systems in the lowland humid forest zone of West and Central Africa. A group of 24 plantain cultivars, representing the major variability in West Africa, was evaluated for nine quantitative characters. The association between growth and yield parameters in this African plantain germplasm was examined to determine if the pattern of quantitative variation in inflorescence and vegetative traits agreed ...

The focus of this study is to provide baseline data for agricultural development activities in Nigeria, with emphasis on understanding the dynamics of spatial and temporal change in annual, seasonal and monthly rainfall during the past 30 years (1961-1990), using daily rainfall data. It was found that annual rainfall has declined in Nigeria over both time and space. The rainfall decline is unprecedented in duration and seasonal expression. The greatest change occurred in the onset of the rainy ...

Cassava sweet potato intercropping experiments were carried out at Ukiriguru (semiarid zone), Tanzania during the period from 1989-91. Four cassava varieties used were, Msitu Zanzibar, Alpim valenca, Mzimbirala and Liongo control. The second experiment tested four cassava planting densities, 6666, 10000, 13333 and 20000 plants per hectare. In the two trials, cassava was planted with single or double rows of sweet potato on the same ridge. Basal dressing of inorganic fertilizers at the rate of 60 ...

A series of pot experiments were conducted to test the effect of phosphorus (P) application and liming on early growth performance of Zea mays, Mucuna pruriens and nine woody species (Albizia ferruginea, Cajanus cajan, Dactyladenia barteri, Dalbergia sissoo, Enterolobium cyclocarpum, Flemingia macrophylla, Gliricidia sepium, Leucaena leucocephala, and Pentacletra macrophylla) on an Ultisol. Low reponse to liming and high response to P application were observed in this trial. Early top growth of ...

Primary data collected over a wide area in Africa show that average cassava root yield is not declining as the population increases because the land is being cultivated more intensively in response to demographic pressures. Although fallow periods are becoming shorter, organic manuring, improved market infrastructures and the use of purchased inputs such as labour compensate for this. The yields of improved cassava varieties in Nigeria show that technology can be relied upon to raise production ...

IT 84S-2140 and IT 85F-1517 (cowpea varieties) susceptible to scab disease caused by Sphaceloma sp. were treated with severely infected cowpea plants in 1989 and 1990 field trials. Different levels of disease intensity were generated by treatment with benomyl using two different methods of application: varying the frequency of application from 4- to 35-day intervals resulted in grain losses ranging between 25–70% in 1989 and 35–50% in 1990. When the concentration of benomyl was varied at a 10-day ...