MANAGEMENT OF ONION DOWNY MILDEW UNDER IPM IN THE NWFP, PAKISTAN

Abstract

The importance of downy mildew that attacks onion in the North ••• West Frontier Province (NWFP) of Pakistan can be judged very well from its estimated loss of more than 50% to the crop. The disease affects both quality and quantity of the produce in the form of undersized, misshapen and less number of bulbs per unit area. The farmers of this province use different fungicides unscrupulously to control the disease. They are unaware of other methods of control such as cultural and biological which may reduce the disease inoculum and environmental pollution. These methods are easy to adopt and bear less expenses. In order to familiarize such methods among the farmers, thk project research was designed to test different host management practices at the first place and to combine the best into an Integrated Disease Management Model (IDMM) for testing during the second phase. Results of the first two years indicated that use of NPK fertilizer 120:90:60 41. kg/ha, plant population 0.5 million plants/ha, 8 irrigations/season, fungicides Ridomil @ 250 g/100 L plus Antracol/Dithane M-45 @ 200/300 g/100 L and herbicide "Roanstar" @ 5 ml/L decreased downy mildew severity substantially and stabilized onion yield. During the third year of the project research, the above mentioned best treatments were combined into an Integrated Disease Management Model (IDMM). This model was verified against Farmers' Own Practices (FOPs) of disease control. The multilocation testing of IDMM proved its superiority over FOPs in minimizing the disease attack and improving the crop yield. The IDMM is easy to be adopted by the farmers as it does not require much professionalism. The use of fertilizers, good variety, optimum plant population and suitable pesticides is common among the farmers. With some modifications as iv suggested in the model, these cultural practices can be conveniently used for downy mildew control. With the use of appropriate cultural controls and limited fungicides, the total cost on the production and protection of onion crop will be reduced. It will also minimize losses from the environmental pollution which threaten human and crop health most frequently. Through the use of IDMM, the productivity will be increased as well as the quality of onions will be improved. This may increase marketing of the produce inside and outside the country. The socio-economic condition of the farmer, within the country will be ameliorated.