Department of Plant Pathology, Marathwada Agricultural University, Parbhani-431402, India.
Leaf curl disease is considered to be one of the economically important viral diseases of tomato worldwide including India. Tomato leaf curl is commonly occurring in all the states of India, including Maharashtra. The disease is caused by Gemini virus. The virus is transmitted exclusively by the whiteflies in persistent manner. Therefore, the role of whiteflies as a vector is of paramount importance in the spread and determining epidemic outbreak of the disease. Considering this present investigation was carried out to understand the factors which determine the outbreak of the disease. The correlation between whitefly population dynamics and disease incidence was found to be equivocal. Though the tomato crop was found vulnerable to leaf curl virus infection at all growth stages but it was highly vulnerable at early growth stages i. e. 60–75 days after transplanting. The incidence of leaf curl appeared 50 days after transplanting and the disease progressed steadily throughout the growing season. The distribution of tomato leaf curl infected plants in field was random which indicated that it was a simple interest disease. Of the various climatic factors, three factors viz. rainy days, temperature (min.) and relative humidity had effect on whitefly activities.
