Economics of Insecticide Use on Staked Tomatoes in Western North Carolina

Abstract

Field studies were conducted in 1988 and 1989 to determine the economic benefits associated with use of various insecticides on fresh-market staked tomatoes in western North Carolina. Tomato fruitworm, Helicoverpa zea (Boddie), was the most important direct insect pest, causing estimated losses of $3,385 and $941/ha in nonsprayed tomatoes in 1988 and 1989, respectively. Indirect damage (i.e., reduction in total yield) due to potato aphid, Macrosiphum euphoribae (Thomas), and tomato fruitworm in 1988 caused additional losses in net profits estimated at $956, $2,186, and $1,687/ha for carbaryl, Bacillus thuringiensis val. Kurstaki, and untreated tomatoes, respectively. The broadspectrum insecticides endosulfan, esfenvalerate, and methomyl were generally more profitable than carbaryl and B. thuringiensis. Under dry weather conditions in 1988, most insecticides were as profitable at 10-d as at 5-d intervals, but under wet conditions in 1989, the shorter-residual insecticides methomyl and B. thuringiensis had higher net profit increases at 5-d opposed to 10-d intervals.