Efficacy of Systemic Aphicides for Control of Melon Aphid on Cantaloupe, 1993

Abstract

Abstract Two greenhouse trials were conducted sequentially to evaluate rates of systemic aphicides for control of melon aphid on cantaloupe. Methods of both trials were the same with the exceptions of the cultivars used, number of replicates and sample intervals. In the first trial, ‘Top Mark’ cantaloupe were planted 16 Aug and arranged in a RCB design with 4 replications. In the second trial, ‘Perlita’ cantaloupe were planted 4 Oct and arranged in a RCB with 3 replications. In both trials, cantaloupe were seeded in 6-inch pots with Metro Mix® Redi Earth growing medium (40-50% peat moss; 50-60% medium vermiculite), thinned to 1 plant per pot when plants reached the 1st true leaf stage, and maintained in a greenhouse at 65°F a 85°F during the trial. Untreated cantaloupe and watermelon plants colonized with melon aphid were interspaced between treated plants as an infestation source during the trial. A general purpose fertilizer was applied at the recommended greenhouse rate, triadimefon was misted over plants with a spray bottle at the recommended rate for powdery mildew control, and plants were irrigated as needed by adding water to plastic trays used to hold each pot. All treatments were applied as a soil drench around the base of each plant after pretreatment counts. Four oz total volume was used for each treatment and the untreated control received 4 oz of water alone. The total number of aphids were counted on three leaves per plant, and each leaf was marked and resampled 3 (1st trial); 4, 6, 8, and 10 DAT (2nd trial). Linear regression analysis was used to determine relationships between aphicide rate and mean number of aphids per leaf. Data were analyzed for treatment differences using analysis of variance and means were separated with Ryan-Einot-Gabriel-Welsch multiple range tests (P ≤ 0.10).