Recent trends of mustard aphid (Lipaphis erysimi) infestation in rapeseed mustard in eastern Rajasthan

Abstract

Field experiments were conducted during 2014-15 and 2015-16 to study the seasonal incidence of mustard aphid (Lipaphis erysimi Kalt.) on different varieties of rapeseed-mustard crops (Brassica sp.). The maximum peak population of mustard aphid were recorded on BSH-1 followed by GSC 6, Rohini  and T 27 under timely sown conditions as well as under late sown conditions. In general the trend was observed as BSH-1 > GSC 6 > Rohini > T 27 for peak population of mustard aphid during different seasons. The study revealed that Late (4th standard week) appearance of mustard aphid leads to low population build up and early appearance (1st standard week) leads to high population build. Alate mustard aphid was observed from 43rd standard week to 12th standard week with peak (145.7 aphids/trap) in 9th standard week and disappeared during 12th standard week during (2014-15). Similarly observations were recorded during 2015-16 week with peak (3447.4 aphids/trap). The results indicated that escape mechanism from mustard can be achieved if the crop would have sown 3 weeks earlier.