Chemical Trials and Effects on Arthropods in Celery, 1989

Abstract

Abstract Celery was transplanted in a sandy loam soil on 11 Aug at the University of California's South Coast Field Station. The plants were sprinkler irrigated for 3 wk and drip irrigated (water pH 7.2-7.5) thereafter. Experimental plots were 3 beds wide (2 rows/bed on 40-inch centers) by 50 ft and separated by a 5 ft buffer with 4 replicates of each treatment in randomized complete block design. Weekly application dates included 22, 28 Sep, 5, 12, 19, 26 Oct and 3, 10, 16 Nov. All chemicals were applied by a tractor-mounted boom sprayer operated at 100 psi. As plant height and foliage density increased, nozzles varied from 2—4 per row and carrier (H20) increased from 50 gal/ac (22 Sep) to 100 gal/ac (28 Sep on). Disc-type cone nozzles incorporated D3 orifice discs, #23 or #25 cores and 50-mesh screens. All treatments received spreadersticker. Antifoam (No-Foam) was used with all treatments. Leafminer populations were evaluated by weekly counts of leafminer prepupae and pupae in four 5'/2 × 11 inch trays/replicate when the plants reached a suitable height. Acutal sampling dates were 27 Sep, 4, 11, 18, 25 Oct and 1, 9, 15 Nov. The number of dead adult parasites of Liriomyza species were recorded in the same manner and on the same dates listed for pupal counts. Evaluation of Lepidoptera populations was based on number of damaged plants found in 25 plants/replicate (100/treatment) from the center two rows of each replicate at harvest (20 Nov). Beet armyworm and black cutworm damage were recorded separately.