Cabbage Looper Control with Esfenvalerate Tank Mixed with Urea Fertilizer, 1991

Field trials were conducted to determine if addition of urea fertilizer to spray tank mixes of Asana XL would affect insecticide efficacy. Collards were transplanted 26 Jul in a Calloway silt loam on the ASU Research Farm in single rows on raised beds spaced 6.6 ft apart with plant spacing at 12 inches. The experiment was arranged in a randomized complete block with 4 replications. Plot size was 1 row, 20 ft long. All plots received season long protection from pests until 10 days prior to test initiation. At that time all plants were fully shucked then sprayed 5 days later with of 0.03 lb AI Asana XL. For the experiment, prilled urea was dissolved in tap water in the spray tank, the insecticide was added, and pH of the final spray mixture determined. Treatments were applied on 26 Aug using a CO2 pressurized backpack sprayer calibrated to deliver 20 gal/acre at 40 psi and equipped with 2 hollow cone nozzles spaced 20 inches apart and directed at a 45° angle toward the center of the plant. Temperature at application time was 89°F with 40% RH. Treatment evaluations were made 31 Aug by sampling 5 randomly selected plants per plot. No. of larvae, damaged leaves, and marketable leaves per plant were determined. In addition, insect damage was rated on a 1 to 5 scale with 1 = no damage, 2 = slight damage (<2 leaves unmarketable), 3 = moderate damage (<3 leaves unmarketable), 4 = heavy damage (>3 leaves unmarketable with <10% loss of leaf area), and 5 = severe damage (>3 leaves unmarketable with >10% loss of leaf area). Phytotoxicity was rated on a 0 to 3 scale with 0 = no damage, 1 = moderate damage (1 leaf damaged), 2 = heavy damage (>1 leaf damaged with <25% of damaged leaves affected), and 3 = severe damage (>1 leaf damaged with >25% of damaged leaves affected). Data including log transformations of insect count data were subject to ANOVA.