PARTIAL CONTROL OF THE SPREAD OF AFRICAN CASSAVA MOSAIC-VIRUS IN BENIN BY INTERCROPPING

A field study on the dynamics of the whitefly, Bemisia tabaci Gennadius, populations and the spread of the virus-induced mosaic disease, ACMV, was carried out using two cassava varieties, Manihot esculenta Crantz, in intercropping with maize (Zea mays L.), cowpea (Vigna unguiculata (L) Walp) and peanut (Arachis hypogeae L.). The investigation was carried out during the 1990's two cropping seasons at Abomey-Calavi in South-Benin. The results showed that the practice of intercropping cassava with maize, cowpea and peanut markedly reduced the population size of whitefly and, consequently, the incidence of disease development in the cassava crop. This reduction both in population size and disease incidence was considered to be an effect of the planting density, diversity as well as the feeding behaviour of the whitefly. The lowest whitefly populations were observed on the cassava plants in intercropping with cowpea and the lowest disease incidence was assessed in the cassava crop associated with cowpea and peanut.