Impact of Insecticides on Tomato Insects 1996

Abstract

Abstract Seedlings were transplanted in a sandy loam type soil on 18 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 block design. Weekly applications were initiated at first fruiting. Application dates were 25 Jul, 1, 8, 15, 22, 29 Aug, and 5, 12, 19 Sep. 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 gpa. Spreader sticker (Leaf Act 80) was included for all treatments at 0.04%, except Fortune AZA and Neemix (+0.5% crop oil) and Aphistar (+ silwet @ 2 oz./lOO gal.). Leafminer populations were evaluated by weekly counts of leafminer prepupae and pupae in four 9 by 11 inch trays/replicate from 30 Jul through 18 Sep, inclusive. On 23-25 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 by H. zed) and external damage (primarily by S. exigua and K. lycopersicella). Leafminer populations were moderate. Some treatments increased leafminer density as compared to the control.