Estimation of fruit damage deviation due to seed borer, Trymalitis margarias Meyrick under different varieties and spacing in sapota

Abstract

A screening trial with eight varieties of sapota against seed borer, Trymalitis margarias Meyrick under normal (10 × 10 m) and high density plantations (5 × 5 m) was carried out. The fruit damage due to seed borer revealed that Kalipatti (7.50%), DHS-2 (5.88%) and Cricket ball (5.55%) had higher infestation, while moderate damage noted in DHS-1 (3.42%) and PKM-1 (3.40%) during both the season. The fruit losses were lesser in PKM-4 (2.77%), PKM-3 (2.46%) and CO-3 (2.34%). The two year data indicated that there was no infestation differences in normal (4.38%) and high density spacing (3.95%) plantations, however the higher fruit damage was noted under normal spacing over high density plantation in individual years. The morphological characteristics like weight, colour and shape of fruit and seed along with number of seeds/fruit and weight loss in seed under different sapota varieties did not showed association with the infestation level of seed borer. However under normal and high density plantation, single hole as well as hole on lower half of fruits was observed cent per cent in fruits of tolerant varieties viz., PKM-1, PKM-4 and CO-3, while it was 60 -90% in other varieties.