No abstract

Population dynamics of cabbage aphid (Brevicoryne brassicae L.) was studied during 2009-10 at Entomology Farm, ICAR Research Complex for NEH Region, Umiam, Meghalaya. Cabbage, cauliflower, knolkhol and broccoli were planted on two different dates at fifteen days interval to study the incidence pattern of cabbage aphid. Early planted crops were relatively safer than late planted crops in relation to aphid infestation. Mean aphid numbers per square inch leaf area were 1.63, 1.44, 2.79 and 1.14 on first plantings and 3.15, 1.39, 3.68 and 1.68 on second plantings cabbage, cauliflower, knolkhol and broccoli, respectively. Correlation study between weather parameters and aphid population showed negative influence of temperature, relative humidity and rainfall on population growth of aphid.