Study on correlation between population of viruliferous whitefly and the percent intensity of cotton leaf curl disease in cotton

Abstract

Cotton Leaf Curl Disease (CLCuD) is a devastating disease in cotton and cause seed cotton yield loss upto 80% in Northern India. Transmission of CLCuD by Bemisia tabaci, the role of alternative weed hosts, infested cotton plants is well understood. However, the relationship of viruliferous whitefly population and CLCuD incidence is still not clear. We aimed to pursue a detailed study on the effect of general whitefly population and viruliferous whitefly population on CLCuD percent disease index (PDI) and their correlation. Three years study showed a decreasing trend in general whitefly population and increasing trend in viruliferous whitefly population in correspondence with the increase in CLCuD intensity from August to October. A highly significant and positive correlation between viruliferous whitefly population on cotton plant and percent diseases index of CLCuD (r2 = 0.945) was observed both at on-station and on-farm multiplication trials. A non-significant positive correlation between whitefly population and CLCuD PDI (r2 = 0.796) and between whitefly population and viruliferous whitefly population (r2 =0.633) was recorded at on-station trials. Thus, it‟s one of its first kinds of research study which shows a positive correlation between viruliferous whitefly population and the level of CLCuD intensity in cotton field for the first time. These results advance our understanding on timely detection of viruliferous whitefly level in the cotton field during the off-season as well as during the crop season. This would help in managing the transmission of CLCuV through the judicious and timely application of management strategies for viruliferous whitefly.