Impact of Insecticides on Celery Insects, 1994

Abstract

Abstract Celery was transplanted in a sandy loam soil on 30-31 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 6 Oct through 21 Nov (total of 8 applications for all chemicals except Avid and Avid + Xentari). Actual dates of applications were: 6, 13, 20, 27 Oct, and 3, 10, 17, 21 Nov. Avid was applied on the first two dates and again for dates 5-6. The Avid + Xentari treatment was the same except that Xentari was applied on dates Avid was not. All chemicals were applied by a tractor-mounted boom sprayer operated at 125 psi. Nozzles were 4 per bed and carrier (H2O) was at 100 gal/ac. 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 5 ½ X 11 inch trays/replicate when the plants reached a suitable height. Actual sampling dates were 15, 25 Oct and 1, 8, 15, 21, 28 Nov. The number of dead adult parasites of1 Liriomyza species was 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 (29-30 Nov). Beet armyworm and black cutworm damage were recorded separately.