DISEASES AND INSECT PESTS OF ONION IN INDIA
The results of the recent surveys conducted during the rainy season (1990) and winter/summer (1990–91) indicated that purple blotch was found to be severe in both periods, with 5.0–96.5% incidence and 0.09–25.93% intensity. Colletotrichum blight was restricted to the rainy season only, and its incidence as well as intensity ranged from 5.45 to 29.45% and 1.9 to 11.4%, respectively. Stemphylium blight was more severe in the winter/summer than in the rainy season (incidence 1.3–100% and intensity 0.04–25.8%). Thrips infestation was observed in both seasons but was more severe in the winter/summer crop (incidence 2%–100% and no. of thrips/plant 0.2–30.3).