Planting Dates and Varieties Vs. Cabbage Aphid, Brevicoryne Brassicae

A study was carried out in the Entomological Research Farm, SASRD, Nagaland University during rabi, 2010–2011. Results showed that planting dates has significant influence on the aphid population with the peak population from 30 DAP to 75 DAP (days after planting), during December to mid-February. Maximum population (8.10 aphids/leaf) was recorded at 30 DAP and minimum (2.32 aphid/leaf) at 90 DAP on 15th December planting. Out of the five varieties tested, maximum population was recorded on G-8 variety (8.83 aphids/leaf) and least on the cultivar Rare Ball (5.26 aphids/leaf). Overall, late planted crop of 15th December harboured less population and variety Rare Ball planted on 30th November was found most ideal in Nagaland condition.