Abstract:
The importance of downy mildew that attacks onion in the North
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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.
