Enzyme-linked immunosorbent assay (ELISA) was used to detect viruses in 649 cowpea leaf samples collected from115 fields during a 3-year survey carried out from 1991 to 1993 throughout all agroecological zones in Nigeria. Six viruses, cowpea aphid-borne mosaic potyvirus (CAMV), blackeye cowpea mosaic potyvirus (BICMV), southern bean mosaic sobemovirus (SBMV), cowpea mottle carmovirus (CMoV), cowpea (yellow) mosaic comovirus (CpMV) and the cowpea strain of cucumber mosaic cucumovirus (CMV-CS) were detected in 390 out of the 649 samples assayed. There was considerable variation in both disease incidence and virus distribution in the different crop habitats within and between seasons. Thus, while SBMV had the highest incidence (27× 4%) and was the most prevalent (66× 7% in 1991, CAMV had the highest incidences (11× 3% and 28× 8%, respectively) and was the most prevalent 33% and 68%, respectively) in 1992 and 1993. CpMV and CMoV remained consistently moderate both in incidence and prevalence throughout the duration of the survey. The detection of the three beetletransmitted spherical viruses (SBMV, CpMV and CMoV) in the Sudan and Sahel Savanna indicates that there is no ecological restriction to the distribution of any ofthe viruses. Incidence ofmultiple infection of up to four and five viruses in individual samples was observed, but mixed infection with two viruses was more prevalent (13%). The potential for horizontal resistance breeding based on common vector transmission is discussed.

Purpose -The purpose of this paper is to identify and assess the key factors that influence the adoption of agrochemicals on plantain farms in Ghana. Design/methodology/approach -The paper employs probit estimation using data from a stratified random sample of 249 farmers in four districts in Ghana. Findings -The results show that adoption of agrochemicals is positively associated with: being literate, older than 40 years of age, having higher income from sales, living in villages distant to Accra (capital of Ghana), having access to hi-tech machinery, being migrant, and being linked to extension services and financial institutions. Contrary to expectation, a farmer's gender and association with farmer-based organizations (FBO) and non-governmental organizations (NGO) did not make a difference. Practical implications -The results suggest that there are no exclusions to innovation systems such as agrochemical adoption based on gender or living in rural areas; women are just as technologically empowered as men, while rural farmers have an option to retain their indigenous management practices or adopt new and improved practices such as using agrochemicals. Major efforts to improve access to agrochemical adoption lie with government extension officers, as the functions of FBO and NGO have yet to make a significant difference. More needs to be done to bring young, illiterate, low income and indigene farmers into inclusive plantain science techniques and applications in Ghana. Originality/value -The paper reveals how vulnerable groups such as rural populations and women plantain farmers are being included in systems that support agrochemical adoption.

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