Evaluation of Biorational Pesticides for Management of the Silverleaf Whitefly on Fresh Market Tomatoes, Spring 1994

Abstract

Abstract On 10 Mar, transplants were set 18 inches apart on raised beds of Eau Gallie fine sand covered with black polyethylene mulch. Plots consisted of three 21-ft long rows on 5-ft centers. Treatments were replicated 4 times in a RCB design and were applied with a tractor-pulled sprayer on 24, 31 Mar, 7, 14, 21, 28 Apr, 5, 12, 19, 24 May and 1 Jun. Each product was applied at 200 psi using yellow Albuz™ ceramic nozzles and at 400 psi using brown Albuz™ ceramic nozzles. As the plants grew, the number of nozzles per row was increased in order to increase gallonage. Thus, 60 gpa were applied the first five sprays (four nozzles), 90 gpa the next three sprays (six nozzles) and 120 gpa for the remaining three sprays (eight nozzles). The terminal leaflet was collected from the 7th or 8th leaf (counting from the top) of each of 10 stems from the middle row of each plot on 25 Apr, 25 May and 10 Jun. The numbers of eggs, crawlers, sessile nymphs and pupae of the silverleaf whitefly (SLWF) were counted on the whole leaflets for the first two evaluations and on a single 2 cm2 disk per leaflet on the last evaluation. All counts were converted to an area basis for analyses. The numbers of leafmines and leafrolls of the tomato pinworm (TPW) were counted by two persons during a 1 min search of the middle row of each plot. Counts of both persons were totalled for analyses. Fruit of marketable size were harvested on 27 May and 8 Jun. They were separated into non-damaged and insect-damaged categories, counted and weighed.