MANAGEMENT OF THE SILVERLEAF WHITEFLY ON FRESH MARKET TOMATOES WITH SOIL AND FOLIAR INSECTICIDE APPLICATIONS, SPRING 2002

Abstract

On 28 Feb, transplants were set 18 inches apart on raised beds of EauGallie fine sand soil covered with white on black low density polyethylene mulch. Plots were three, 21-ft-long rows on 10-ft aisles and 5-ft centers and were irrigated by a seepage sub-irrigation system. Treatments were replicated four times in a RCB design. Admire, Platinum and V-10112 were applied on 28 Feb to each plant in 4 oz of water. Activol, Aza-Direct and Hexacide were applied weekly. The remaining products were to have been applied at the pre-determined density of five whitefly sessile nymphs and/or pupae/10 leaflets (Table 1); however, on 9 May only treatments with Oberon were applied before uncontrollable circumstances stopped spraying. All treatments were applied on 26 May. 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 90 (six nozzles open) or 120 (eight nozzles open) gpa. Because of a heavy population of southern armyworm larvae, Javelin (2 lb/acre), XenTari (2 lb/acre), Confirm 2F(16 oz/acre) or Avaunt 30WG (3.5oz/acre) were applied weekly. The number of plants in each plot with definite visual symptoms of whitefly-vectored geminivirus, primarily tomato yellow leaf curl virus (TYLCV), were recorded weekly beginning 19 Mar. The numbers of sessile nymphs (2nd and 3rd instars) and pupae (4th instar or red eye nymphs) of the silverleaf whitefly were counted on the terminal leaflet from the 7th to 8th leaf counting from the top of each of ten plants in the center row of each plot about weekly beginning on 31 Mar. Fruit were harvested on 4 Jun from the middle 10 plants of the middle row of check plots and plots treated only with either Admire or Platinum. Fruit with zippering, cat-facing or large blossom-end scars were culled as defective and counted and weighed. The remaining fruit were graded for size by machine where extra large fruit were > 2.75 inches in diam, large were 2.51 to 2.75 inches in diam, medium were 2.26 to 2.5 inches in diam and small were ≤ 2.25 inches in diam. All size categories were counted and weighed. Small fruit are considered too small for marketing and are culled.