Effect of Insecticides on Tomato Insects 1995

Abstract

Abstract Seedlings were transplanted in a sandy loam type soil on 21 June at the University of California’s South Coast Field Station in Santa Ana, California. Experimental plots were 4 rows wide (5-ft centers) by 40 ft long and separated by a 5-ft buffer. The tomato transplants were drip irrigated (water pH 7.2-7.5). Treatments were replicated 4 times in a RCB design. Weekly applications were initiated at first fruiting. Application dates were 27 Jul, 3, 10, 16, 24, 30 Aug, and 7, 14 Sep. (except Agrimek which was applied on 27 Jul 3, 24, 30 Aug, and Agrimek + Lannate in which Lannate was applied every wk). A tractor-mounted boom sprayer with 6 nozzles per row incorporated D-3 orifice disks, #25 cores, and 50 mesh screens. Operating pressure was 100 psi delivering 100 gal/acre. Spreader sticker (Leaf Act 80) at 0.04% was included for all treatments. Leafminer populations were evaluated by weekly counts of leafminer prepupae and pupae in four 9 by 11 inch trays/replicate from 1 Aug through 12 Sep., inclusive. On 18-21 Sep., 200 mature-green to ripe fruit were harvested from the center 2 rows of each replicate (800 per treatment) and examined for internal damage (primarily H. zea) and external damage (primarily S. exigua and K. lycopersicella). Leafminer populations were low early, then moderate late in this test. Some treatments increased leafminer density as compared to the control. Beet armyworm and tomato pinworm populations were moderate as were tomato fruitworm populations. No phytotoxicity was observed in any treatment.