Chemical Trials and Effects on Insects in Celery, 1993

Abstract

Abstract Celery was transplanted in a sandy loam soil on 17 Aug at the University of California’s South Coast Field Station. The plants were sprinkler irrigated for three weeks and drip irrigated (water pH 7.2-7.5) thereafter. Experimental plots were four beds wide (two rows per bed on 40-inch centers) by 40 ft and separated by a 5 ft buffer with four replicates of each treatment in a randomized complete block design. Applications were weekly from 30 Sep through 24 Nov (total of 9 applications for all chemicals except Avid and Avid + Lannate). Actual dates of application were: 30 Sep, 6, 14, 20, 27 Oct, and 3, 10, 17, 24 Nov. Avid was applied on the first two dates and again for dates 6-9 in Nov. The Avid + Lannate treatment was the same except that Lannate was applied on dates 3-5. All chemicals were applied by a tractor-mounted boom sprayer operated at 125 psi. Nozzles were 4 per bed and carrier (H20) was at 100 gal/acre. Disc-type cone nozzles incorporated D3 orifice discs, #25 cores and 50-mesh screens. All treatments received spreader-sticker. Antifoam (No-Foam®) was used with all treatments. Leafminer populations were evaluated by weekly counts of leafminer prepupae and pupae in four SVi × 11 inch trays/replicate when the plants reached a suitable height. Actual sampling dates were 5, 13, 19, 27 Oct and 2, 9, 16 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 per replicate (100/treatment) from the center two rows of each replicate at harvest (30 Nov). Beet army worm and black cutworm damage were recorded separately.