Evaluation of Potential Controls of Sweetpotato Whitefly on Cauliflower, 1991-1992

Five insecticide treatments were applied to cauliflower grown by Pasquinelli Produce, Yuma, AZ, for control of SPWF. Treatments were applied three times, two weeks apart (20 Nov, 4 and 18 Dec). Treatments were made with a back-pack sprayer with four TX2 nozzles calibrated to deliver 35 gal/acre on 20 Nov, and with four TX4 nozzles calibrated to deliver 60 gal/acre during Dec treatments. Gallonage was increased to provide better coverage. Nozzles were angled to provide entire plant coverage with 2 nozzles angled up into the plant and the other two angled down into the plant. Treatments were replicated four times in a randomized complete block design. Plots consisted of a 25 ft row on single beds with 40 inch centers. SPWF adult numbers were low to moderate at time of initial treatment, with adequate numbers of nymphs and eggs present. Samples were obtained after each application (25 Nov, 16 Dec, 8 Jan) based on accumulated heat units for SPWF development. Samples consisted of the lower 6 leaves of four plants/plot on 25 Nov and 8 Jan, and the lower 8 leaves on 11 Dec.