Association of Fruit and Shoot Borer Infestation in Eggplant with Morphological, Yield, Quality and External Weather Variables

Abstract

The association of the fruit and shoot borer (Leucinodes orbonalis Guen) Infestation in eggplant with morphological, yield, quality and weather variables was studied at Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India, during the spring–summer (February–June) of 2012–2013 and 2013–2014 and autumn–winter (September–March) of 2013–2014 and 2014–2015. Earlier infestation occurred on the plants during the spring–summer, while late infestation of the pest was observed during the autumn–winter. The Number of infested shoots per plant, per cent shoot infestation, number of infested fruits per plant, per cent fruit infestation and larvae per fruit were greater during the spring–summer months than during the autumn–winter months. The fruit infestation had a significant negative association with fruit yield per plant. The number of infested fruits per plant was positively and significantly associated with primary branches per plant, fruits per plant and fruit yield per plant. A significant negative correlation was observed between spines on stem and number of infested shoots per plant, and the correlation of number of infested fruits per plant with the spines on the stem, petiole and pigmentation on leaf lamina was positively significant. Genotypes with purple colour flowers and fruits had greater eggplant fruit and shoot borer (EFSB) infestation. The long slender fruit shape and clustered fruiting habit promoted the EFSB infestation. The TSS and anthocyanin in peel were found as the phagostimulants, while the high total phenols content and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging capacity were the feeding deterrents. The per cent of infested fruits per plant exhibited a positive correlation with maximum (Tmax), average (Tavg) and day temperatures. Larvae per fruit had a positive association with maximum temperature (Tmax), day temperature and helio-thermal units.