Seasonal Incidence of Insect Pests on Mungbean (Vigna radiata) in Correlation with Meteorological data

Abstract

Background: Mung bean is important pulse crop in India due to its nutritional value. Its grain contains protein, fat, carbohydrate, vitamin and minerals therefore human uses it in various ways in food. Mung bean crop cultivated in kharif, rabi and summer season in India. Various species of insect pests are infested to mung bean crop and cause very harmful effect to crop and farmer. These pests decrease productivity and quality of mung bean. Methods: Field experiment was carried out for the study of seasonal incidence of insect pests on RMG-62 variety of green gram during kharif season 2019. Mung bean was grown on a plot size of 25 m × 25m with 50 cm row to row and 20 cm plant to plant spacing. Randomly selected 20 plants from weekly interval to record population of insect pests. The population of jassid and whitefly was recorded by counting number of pests on 2 upper, 2 middle and 2 lower leaves of a plant whereas population of aphid was recorded by counting number of aphid on 10 cm twig/plant. Result: The mean population of aphid, jassid and whitefly were recorded. Incidence of aphid started during 33th standard week with 0.9 aphid/10cm twig/plant, jassid and whitefly started during 32th standard week with 0.3 jassid/6 leaves/plant and 2.1 whitefly/6 leaves/plant, respectively. Peak mean population of aphid, jassid and whitefly reached during 36th standard week with 10.2 aphid/10cm twig/plant, 10.1 jassid/6 leaves/plant and 14.1 whitefly/6 leaves/plant, respectively. Simultaneously six species of insect pests also infested green gram, these were Mylabris pustulata, Helicoverpa armigera, Trichoplusia ni., Lampides boeticus, Spoladea recurvalis and Diaphania indica. The population of aphid, jassid and whitefly positively correlated with temperature. Population of aphid and whitefly had positive correlation with humidity, whereas jassid population had positive correlation with minimum humidity and negative correlation with maximum and average humidity. All three pests expressed negative correlation with rainfall.