FOLIAR AND SOIL APPLICATIONS OF INSECTICIDES FOR CONTROLLING SILVERLEAF WHITEFLY ON FRESH MARKET TOMATOES, FALL 2000

Abstract

On 21 Sep, transplants were set 18 inches apart on raised beds of EauGallie fine sand soil covered with white polyethylene mulch. Plots were three-21-ft long rows on 5-ft centers and were irrigated by seepage, subsurface irrigation system. Treatments were replicated four times in an RCB design. Admire and Platinum were applied on 21 Sep to each plant in 4 oz of water. Applaud and Knack were applied once on 15 Nov as the controlling effects of Admire diminished and whitefly densities approached or reached 3 5 whitefly sessile nymphs and/or pupae/10 leaflets. Foliar applications were made with a high-clearance, self-propelled sprayer operated at 200 psi and 3.4 mph. It was fitted with eight Albuz orange nozzles per row and delivered 60 (four nozzles open), 90 (six nozzles open) or 120 (eight nozzles open) gpa, depending upon plant height. Because of a moderate population of southern armyworm larvae, Mattch (2 qt/acre), Javelin (2 lb/acre) or SpinTor (6 oz/acre) were applied weekly. The number of plants in each plot with definite symptoms of whitefly-vectored geminivirus, primarily tomato yellow leaf curl virus, were recorded weekly. The numbers of sessile nymphs (2nd and 3rd instars) and pupae (4th instar or red eye nymphs) of the silverleaf whitefly were counted weekly on the terminal leaflet from the 7th to 8th leaf counting from the top of each of 10 plants in the center row of each plot.