Impact of crop geometry and fertilizer doses on the population density of insect-pests on pole bean (Phaseolus vulgaris L.) under net house conditions

Studies were conducted on the incidence of major pests viz. serpentine leaf miner, spider mite, leafhopper, and tobacco cutworm of pole bean in relations to the crop spacing and fertilizer application, during rabi 2019–20. Spacing between crops and nutrient nourishment distinctively governed the activity of insect pests in pole bean crop (Phaseolus vulgaris L.), grown under the net house. It was revealed from the study that when the crop was raised at a wider spacing of 45×60 cm with fertigation of 125% RDF (Recommended dose of fertilizer) (78.12:125:93.75 NPK kg per ha) resulted in the lowest population density of the infesting insect whereas the highest at the interaction of 45×30 cm spacing and 75% RDF (46.87:75:56.25 NPK kg per ha).This suggested that a wider spacing and increased dose of recommended fertilizer could lessen the pest population and vice-versa conditions could increase it. Hence it can be a non-chemical implication for the management of insect-pest under the net house.