Effect Insecticides on Lepidopter and Leafminers on Tomatoes, 1987:

Abstract

Abstract Seedlings were transplanted in a sandy loam type soil on 7 Jul at the University of California’s South Coast Field Station in Santa Ana. Experimental plots were 4 rows wide (5-ft centers) by 40 ft long and separated by a 5-ft buffer. The tomato transplants were sprinkle irrigated for 1 wk and drip irrigated thereafter (water pH 7.2-7.5). Treatments were replicated 4 times in a randomized complete block design. Weekly applications were initiated at first fruiting. Application dates were 7, 20, and 27 Aug; 3, 10, 17, and 14 Sep; and 1 and 8 Oct. A tractor-mounted boom sprayer with 4-6 nozzles/row (as plant height and density increased) incorporated D-3 orifice disks, 23-25 cores, and 50-mesh screens. Operating pressure was 100 psi delivering 100 gal/acre. Spreader-sticker (Leaf Act 80) was included for some treatments at 0.04%. Leafminer populations were evaluated by weekly counts of leafminer prepupae and pupae in 4 9- by 11-inch trays/replicate from 26 Aug through 7 Oct. On 14 and 15 Oct, 200 mature green to ripe fruit were harvested from the center 2 rows of each replicate (800/treatment) and examined for internal damage (primarily tomato fruit worm) and external damage (primarily beet army worm) and for tomato pinworm.