Insecticide Control of Sweetpotato Whitefly on Broccou and Lettuce, 1991

The study was conducted in a randomized complete block design with four replications at the USDA-ARS Irrigated Desert Research Station at Brawley, California. Head lettuce, ‘Empire MI’, was planted at 28 seeds/m of seed row, and hybrid broccoli. ‘Packman’, at 25 seeds/m of seed row, each in separate plots, on 18 Sep. Plots of each crop were two rows (beds) in 40-inch row spacings with rows 20 ft long. Seed rows of each crop were spaced 20 inches apart on a bed. Plots were separated by two fallow rows and 20-ft fallow alleys that separated experimental blocks. Treatments were (1) 0.53 lb Al/acre of NTN 33893 granular formulation applied on the soil surface above seed rows, (2) foliar application of NTN 33893 (240 FS) at 0.13 lb Al/acre, (3) foliar applications of 0.5% liquid detergent, (4) foliar applications of 1% soybean oil plus 0.7% oil emulsifier (Comate-102), (5) foliar application of 0.08 lb Al/acre of Capture, and (6) untreated plots. NTN 33893 granules were applied immediately after planting. Foliar applications were made on 1, 15, and 22 Oct with a backpack sprayer to deliver 32 gal of spray per acre. Ten leaves from each plot were sampled four times at weekly intervals beginning on 7 Oct. Initial samples were 6 days after the first foliar sprays and 19 days after soil application of granular NTN 33893.