Impact of Weather Parameters on Population Dynamics of Cabbage Aphid (Brevicoryne brassicae L.) on Kale (Brassica oleracea var. acephala)

Abstract

Studies on “population dynamics of Cabbage Aphid (Brevicoryne brassicae L.) on Kale (Brassica oleracea var. acephala)’’ in relation to weather parameters revealed cabbage aphid (Brevicoryne brassicae L.) as a major pest on Kale. The incidence of cabbage aphid commenced from 16th standard meteorological week (SMW) with a population of 2.02 (aphids/plant). The population of cabbage aphid started increasing and reached its peak in 25th SMW with a population of 137.16 (aphids/plant) after that the population started declining gradually in 26th SMW with a population of 83.14 (aphids/plant). However, the mean population of nymphs during 16th SMW was (2.02 ± 0.46) which gradually started increasing and was highest in 25th SMW (32.68 ± 0.74). The mean population of adults during 17th SMW was (8.24 ± 0.38) and was highest during 25th SMW (62.12 ± 0.50) and the mean population of winged aphids during 18th SMW was (7.10 ± 0.42) which gradually started increasing and attained its peak during 25th SMW (42.36 ± 0.41) respectively. Correlation between maximum and minimum temperature showed positive correlation with cabbage aphid population. Relative humidity of morning showed non-significant negative correlation while relative humidity of evening exhibited positive non-significant correlation. Rainfall were found non-significant positive correlation.