Estimation of boll damage by pink bollworm Pectinophora gossypiella in cotton under different sowing dates

Abstract

The present investigation was carried out at the research farm of Cotton Research Unit, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, during kharif 2016-17. Four different cotton cultivars were used to estimate pink bollworm damage with three different sowing periods in factorial randomized block design. The results revealed that among the different cotton cultivars, minimum green boll damage (35.00%) due to pink bollworm was recorded on arboreum hybrid (Suvarna) whereas maximum (48.88%) was recorded in Non Bt hirsutum hybrid (DCH-32). Maximum pink bollworm infestation (18.92%) in loculi at harvest was observed in early sowing of Non Bt hirsutum hybrid whereas minimum loculi damage (13.69%) was recorded in timely sown arboreum variety. Maximum seed cotton yield (11.08 q/ha) was recorded in Bt BG II hybrid (RCH-2) whereas the minimum (6.43 q/ha) was recorded in arboreum variety (AKA-7). Maximum pink bollworm infestation at harvest was observed in early sown (5th June) non Bt hirsutum hybrid (DCH-32), whereas minimum infestation was recorded in timely sown (25th June) of arboreum variety (AKA-7).