DEVELOPMENT OF COMBINED USE OF NEEM (AZADIRACHTA-INDICA) AND WATER MANAGEMENT FOR THE CONTROL OF CULICINE MOSQUITOS IN RICE FIELDS

Crude neem products have earlier shown considerable promise for contro l of culicine mosquito vectors in rice fields as a by-product of their agricultural use as fertilizers, but suffer from disadvantages of bul kiness and lack of stability in storage. Relatively stable lipid-rich fractions of neem were shown to be as effective as good-quality crude neem products in control of breeding of culicine vectors of Japanese e ncephalitis, and also produced a slight but significant reduction in p opulations of anopheline pupae. Neem-based formulations coated over ur ea significantly increased grain yield, but used alone did not, wherea s combining the use of neem-coated urea and water management by interm ittent irrigation had a greater effect on grain yield than that of wat er management alone. The neem fractions were relatively cost-effective , and the combined water management and neem-coated urea strategy is a cceptable to farmers, who are already aware of the benefits of the use of neem-coated urea, and of water management. This technology therefo re has considerable promise as an environmentally benign method of ric e-field mosquito control that could be sustainably implemented by farm ers.