Influence of Weather Parameters on Seasonal Incidence of Citrus Leaf Miner ( Phyllocnistis citrella Stainton) in Sweet Orange cv. Sathgudi

摘要

Seasonal activity of the citrus leaf miner, Phyllocnistis citrella Stainton was investigated during 2009 and2010 in Sweet Orange at Citrus Research Station, Tirupati, Andhra Pradesh. The leaf miner activity was noticed throughout the year with peak infestation during winter (September to January) months and low or nil damage in peak summer (April, May) months. Peak infestation of P. citrella was recorded as 38.4% and 35.4% during the months of December and October in 2009 and 2010 respectively. During the entire study period leaf damage caused by P.citrella ranged between 0.3 to 38.4%. Correlation studies of the pest incidence with meteorological data from 2001 -2010 indicated that pest damage was positively correlated with both morning (RH1) and evening (RH2) relative humidity (r = 0.561207 and 0.436502) and negatively correlated with minimum temperature (r=0.62829) and wind velocity (r = -0.51968). Regression analysis resulted that about 79% contribution of observed variation in pest infestationis due to the biotic (existing pest activity on available new flush) and abiotic factors (Temperature, Relative humidity and wind velocity) together.