Association of weather parameters with the incidence of red spider mite, Tetranychus urticae Koch infesting brinjal

Abstract

With a view to know the effect of weather parameters on activity of red spider mite, Tetranychus urticae Koch infesting brinjal, investigation on “Population dynamics and management of red spider mite, Tetranychus urticae Koch infesting brinjal” were carried out under field condition during Kharif (September–February, 2021-22) at the Instructional Farm, College of Agriculture, Junagadh Agriculture University, Junagadh, Gujarat. The population of red spider mite was commenced from 37th SMW (2nd week after transplanting) and continued till 5th SMW to the tune of 0.44 and 0.98 mite/4 cm2 per leaf, respectively. However, the pest population was increased gradually with crop growth and reached to peak in 45th SMW to the tune of 18.40 mite/4 cm2 per leaf. With the crop maturity the population of T. urticae was decreasing gradually from 45th to 5th SMW and then finally vanished out. The red spider mite, T. urticae population remains active throughout the crop season with the population ranging from 0.98 to 18.40 mite/4 cm2 per leaf. The red spider mite, T. urticae had the highly significant positive correlation with maximum temperature (r = 0.658**). While, the pest having significant negative correlation with morning relative humidity (r = -0.585**) and evening relative humidity (r = -0.458*) at high and moderate level, respectively. The minimum temperature (r = 0.011) and bright sunshine hour (r = 0.214) were non-significant positive correlated with red spider mite population among studied parameters. However, rainfall (r = -0.403) showed negative non significant correlation with mite population.