Threshold based spraying of flubendiamide for the management of brinjal shoot and fruit borer, Leucinodes orbonalis (Lep.: Pyralidae)

Field experiment was conducted to determine the economic threshold for spraying of flubendiamide against the brinjal shoot and fruit borer. Flubendiamide was applied based on 10 thresholds including 2% shoot infestation, 5% shoot infestation, first fruit set + 2% fruit infestation, first fruit set + 5% fruit infestation, 2% fruit infestation, 5% fruit infestation, 2% shoot + 2% fruit infestation, 5% shoot + 2% fruit infestation, 5% shoot + 5% fruit infestation and schedule spray at 7 days interval. Flubendiamide applied at 2% shoot + 2% fruit infestation reduced the highest percent of shoot (87.46%) and fruit (81.43%) infestation over control and also produced the highest healthy (13.26 t/ha) and total fruit yield (13.77 t/ha) of brinjal and similar results were obtained for 5% fruit infestation. The highest benefit-cost ratio (BCR) was obtained (7.45) by application flubendiamide at 5% fruit infestation with 8 applications and that was the lowest (1.84) for schedule spray at weekly intervals with 16 sprays. Flubendiamide applied at 2% shoot + 2% fruit infestation had the BCR of 2.92 with the highest number of spray (19). Considering number of sprays, marketable yield of brinjal and also BCR, 5% fruit infestation was considered as economic threshold of flubendiamide spraying for the management of brinjal shoot and fruit borer.