INSECTICIDES FOR WHITEFLY AND TOMATO YELLOW LEAF CURL VIRUS MANAGEMENT ON FRESH MARKET TOMATO, FALL 2011

Abstract

The efficacy of 14 programs of insecticides were evaluated for control of SPW and tomato yellow leaf curl virus (TYLCV), which is vectored by SPW, in tomato at the Gulf Coast Research and Education Center, Wimauma, Fla. ‘Florida 47’ transplants were set on 20 Sep, at 18-inch spacing, in raised beds of Myakka fine sand, covered with white virtually impermeable mulch, spaced on 5-ft centers. Plants were irrigated and fertilized by a drip irrigation system. Each plot consisted of 42 plants in three 21-ft long rows and was separated by 10 ft of unplanted bed within rows and 12 ft between rows. Treatments were replicated four times in a RCB design. All treated plots were drenched, shortly after transplanting, with Admire Pro or HGW86 200 hand ladled in 4 fl oz of preparation per plant (Table 1). The foliar treatments were applied using a high clearance sprayer, fitted with Albuz orange nozzles, pressurized to 200 psi, and calibrated to deliver 60 gpa (early season) or 90 gpa (late season) (Table 1). SPW densities and tomato yields were assessed on the middle ten plants of the middle row of each plot. Adult SPW densities were sampled by examining the third leaf from the top on two stems per plant and recorded as the number per 20 leaves. Immature SPW densities were sampled from the terminal leaflet of a 7 or 8 leaf from each of ten plants and recorded, as SPW eggs, 1, 2 and 3, and 4 instars per ten leaflets. All plants in a plot that possessed TYLCV symptoms were recorded weekly. Fruit were harvested (8 Dec) and graded for size by machine, where extra large fruit were > 2.75 inches in diameter, large were 2.51 to 2.75 inches in diameter, medium were 2.26 to 2.5 inches in diameter and small were 2.25 inches or less in diameter, or culled if defective. Numbers and weights of all categories were recorded. Counts of immature SPW forms were transformed √(x+0.5) and cumulative weekly percent of plants showing TYLCV symptoms were calculated and transformed arcsine [√(%TYLCV/100)] prior to ANOVA. Means were separated by Fisher’s Protected LSD (P=0.05). All means were reported in the original scale.