INFLUENCE OF INSECTICIDE FORMULATIONS AND DISCHARGE RATE ON SPRAY CHARACTERISTICS AND INCIDENCE OF MAJOR INSECT PESTS ON FCV TOBACCO

Abstract

Investigations were conducted to determine the influence of insecticide formulations on spray characteristics and insect pest incidence in a replicated field trial on flue-cured Virginia (FCV) tobacco during 2013-15. Spray characteristics indicated that at 25 days after planting (DAP), imidacloprid 200 SL emitted through Hi-tech sprayer at a discharge rate of 450 ml/min at 40 PSI pressure with a walking speed of 3.6 - 4 kmph were superior with higher droplet density (67/sq cm), lower uniform coefficient (1.51) and higher coverage (0.66) on plant canopy. At 45 DAP, spraying with novaluron 8.8 SC, 450 ml/min through Hi-tech sprayer exhibited superior spray characteristics of higher droplet density (62), lower uniform coefficient (1.52) and higher coverage (0.65). The treatment comprising initial two sprays with imidacloprid 200 SL and subsequent two sprays with novaluron 8.8 SC applied through Hi-tech sprayer at a discharge rate of 450 ml/min at 40 PSI showed lower uniform coefficient and higher spray coverage on plant canopy which resulted in significant reduction in infestation of aphid, leaf eating caterpillar and budworm with higher cured leaf yield.