EFFECT OF INSECTICIDES ON CELERY INSECTS ...

(E25) CELERY: Apium graveolens L., 'Conquistador' EFFECT OF INSECTICIDES ON CELERY INSECTS, 2000 G. S. Kund, W. G. Carson, and J. T. Trumble Department of Entomology University of California Riverside, CA 92521 Phone: (909) 787-4297 Beet armyworm (BAW): Spodoptera exigua (Hübner) Leafminer: Liriomyza trifoilii (Burgess)

Populations of BAW were high throughout the growing period (over 38% of control plants damaged). Treatments of Mustang, Confirm, RH 2485 (Intrepid), and Lannate provided the best control (Table 1). Leafminer populations were low throughout the season (Tables 2 and 3). No phytoxicity was observed in any treatment.

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Celery was transplanted in a sandy loam type soil on 30-31 Aug at the University of California's South Coast Research and Extension Center. The plants were sprinkler irrigated for 2 wk and drip irrigated (water pH 7.2-7.5) thereafter. Experimental plots were four beds wide (2 rows/bed) on 40-inch centers by 40 ft long and separated by a 5-ft buffer with four replicates of each treatment in an RCB design. Weekly applications were initiated 27 Sep through 30 Nov (total of 10 applications for all chemicals). Actual dates of application were 27 Sep; 5, 12, 19, and 26 Oct; and 2, 9, 16, 21, and 30 Nov. All chemicals were applied by a tractor-mounted boom sprayer operated at 125 psi. Nozzles were four per bed and carrier (water) was at 100 gpa. Disc-type cone nozzles incorporated D3 orifice discs, # 25 cores and 50-mesh screens. All treatments received spreader-sticker at 125% vol/vol (Activator 90), except Confirm and RH 2485 (Latron CS7 at 0.125% vol/vol), and Lepinox and Mustang (X-77 at 0.125% vol/vol). Leafminer populations were evaluated by weekly counts of leafminer prepupae and pupae in four 5-1/2 by 11-inch trays/replicate when the plants reached a suitable height. Actual sampling dates were 10, 17, and 24 Oct and 2, 7, 14, 20, and 27 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 BAW populations was based on number of damaged plants found in 25 plants per replicate (100/treatment) from the center two beds of each replicate at harvest (12 Dec).


