Flower bud infestation pattern of Leucinodes orbonalis on brinjal with respect to different environmental parameters

Abstract

Brinjal Shoot and Fruit Borer (BSFB), Leucinodes orbonalis Guenee is a major pest of brinjal known for infesting shoot and fruits causing substantial yield loss in the crop. However, it was observed that this insect pest also infests the flower buds leading to premature flower drop and poor fruit setting. The extent of flower bud infestation, its variation within and between the seasons and the effect of various environmental parameters on its variation was studied during the kharif and summer seasons of 2009-10 and 2010-11 at Keonjhar, Odisha. During kharif season, flower bud infestation initiated from 2nd week of July in both the years of study with peak infestation at 3rd week of September (41.45%) during 2009 and 1st week of October (38.33%) in 2010. During summer season the larval infestation on the flower buds was noticed for the first time on 2nd week of February with two peak infestation levels during the crop growth period. The initial peak was observed 1st fortnight of April (40.33% in 2010 and 38.42 % in 2011) and the second peak was attained on 3rd week of May in both the years (37.55% in 2010 and 36.29% in 2011). Among the environmental parameters, temperature had positive and relative humidity had negative influence on the variation in flower bud damage and these environmental parameters had major contribution in the fluctuation of flower bud infestation by BSFB.