Indigenous cowpea production and protection practices in Benin.
A survey involving more than 129 farmers was conducted in 1998 and 1999 in Ouémé, Benin, to investigate the importance of pests and diseases as constraints to cowpea (Vigna unguiculata) production. Results indicated that in the Ouémé valley, Sclerotium rolfsii [Corticium rolfsii] and Aphis craccivora are specific concerns. Weeds such as Justicia anselliana, Ipomoea aquatica and Commelina erecta were also reported as being troublesome. On the Ouémé plateau, Imperata cylindrica was reported to be a major weed. Callosobruchus maculatus and Bruchidius atrolineatus caused up to 100% loss within a few months in storage. In addition, birds and rodents are also reported. In certain areas on the plateau, farmers have developed pest control methods based on indigenous knowledge. In the valley, the population density of Eichhornia crassipes during flooding is used by farmers to predict aphid infestation. A number of plant species used to protect cowpea are reported. In Gbékandji village, natural enemies such as Rhabdepyris sp., Evania sp. and Chelonus sp., were observed. They were rare in the valley, where farmers rely on chemical control. Farmers reported alternative hosts of cowpea pests from the families Fabaceae (Cajanus cajan, Centrosema pubescens, Crotalaria retusa, Indigofera hirsuta, Lonchocarpus cyanescens, L. sericeus, Pterocarpus santalinoides and Tephrosia bracteolata), Mimosaceae (Mimosa pigra and Prosopis africana), Ceasalpiniaceae (Cassia ariculiformis, Cassia hirsuta, Cassia obtusifolia, Cassia occidentalis and Cassia siamea), Capparidaceae (Cleome rutidosperma and Cleome viscosa) and Pontederiaceae (Eichhornia crassipes). Based on the hierarchy of constraints, sustainable integrated pest management technologies are being developed with farmers, using a participatory approach.