Response of Melon Aphid to Rates of Admire and CGA 215944 on Watermelon, 1993

Abstract

Abstract ‘All Sweet’ watermelon were seeded in 4-inch pots with Metro Mix® Redi Earth growing medium (40-50% peat moss; 50-60% medium vermiculite) on 18 Jun and maintained in a greenhouse at 65°F a 85°F during the trial. Plants were placed outside the greenhouse two weeks prior to treatment to allow natural colonization by melon aphids. Forty-four plants of uniform size and initial aphid numbers were selected for use in the study. Plants were transplanted into 6-inch pots and returned to the greenhouse. Peters general purpose fertilizer was applied at the recommended greenhouse rate on 22 Jul and plants were irrigated as needed by adding water to plastic trays used to hold each pot. All treatments were replicated 4 times in a RBC block design. Eleven treatments, five serial dilutions of two aphicides and an untreated control, were applied as a soil drench around the base of each plant on 27 Jul 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 melon aphids was counted on 3 leaves per plant 6, 10, and 14 DAT. Linear regression analysis was used to determine relationships between aphicide rate and mean number of aphids per leaf. Analyses of variance were used to distinguish differences in aphid numbers and among aphicide rates. Means were separated with Ryan-Einot-Gabriel-Welsch multiple range tests (P ≤ 0.10).