Potential of neem, Azadirachta indica A. Juss., in the management of Chilo partellus (Swinhoe) on maize in Kenya

The efficacy of neem (dirachta indica A. Juss.) seed powder and aqueous extract against spotted stem borer, Chilo partellus (Swinhoe), on maize (Zea mays) cultivars was investigated in western Kenya. Hybrid 511 and ICZ3 maize plants were infested with blackhead stage egg batches of C. partellus three weeks after crop emergence. Neem seed powder, neem seed powder-sawdust mixture and a 10 % aqueous neem seed extract were applied four weeks after crop emergence. Dipterex was used as a check treatment and plots with untreated plants were included as controls. Foliar application of neem seed products and chemical insecticide considerably suppressed the densities of C. partellus, markedly reduced leaf damage and stem-tunnelling, and improved yield in both cultivars. Application of about 3 g plant/neem seed powder and 500 l/ha of 10 % aqueous neem seed extract applied four weeks after crop emergence provide adequate protection against damage by C. partellus comparable to conventional insecticide and avert consequent yield loss.