Morphotype diversity of Corchorus olitorius and influence of agricultural practices on its potential major pest insects

Abstract

Abstract Corchorus olitorius L. is one of the traditional leafy vegetables of high food and socio-economic value in Africa. Although widely exploited, its varietal diversity is unknown and its domestication remains challenged by pests and diseases presently observed among subsistence users. This study aims to determine the morphotype diversity of C. olitorius in Southern Benin and the durability of its agroecosystem by the influence of agricultural practices on the major pest insects related to its production. Using participatory research methods, surveys were conducted in 21 villages randomly selected across the study area. Results revealed seven different morphotypes of C. olitorius, three of which were wild but used in traditional medicine and four were cultivated. Among the nine constraints reported by farmers, the attack of seven pest insects and the non-distinction of the seeds of the different cultivated morphotypes are the two most important constraints. The seven most common potential pest insects observed by between 10–100% of the farmers, in study area are: Acrea sp, Aulacophora Africana, Helicoverpa armigera, Spodoptera litoralis, Zonocerus variegatus, Podagrica spp. and Acrea acerata. The infestation by these insects were not linked to specific morphotypes of C. olitorius, but varied by locality. The agricultural practices that might influence the presence of any C. olitorius pests were intercropping and dormancy cutting, seedling after sowing and number of harvests. This information will contribute to a better production of the varieties of C. olitorius and the different crop associations could be integrated into methods of ecological management of the pests of C. olitorius.