Evaluation of Combinations of Fulfill and Curacron for Control of Cotton Aphids, 1997

Cotton was planted 19 Jun in 40-inch rows (8-row X 75-ft plot) at the Texas Agricultural Experiment Station at Chillicothe, Texas. The experimental design was a randomized complete block, with 4 insecticide treatments and a check replicated 4 times. Cotton was inspected for aphids on 17, 22, and 29 Jul to determine the treatment threshold of 20 aphids per leaf. Ten leaves from the top half and 10 leaves from the lower half of plants from each plot were examined, and the numbers of aphids were counted and recorded on each inspection date. Pre-treatment counts were made and the insecticide treatments were applied on 5 Aug. Treatments were applied with a John Deere High Cycle 6000 sprayer. Spray drops were used to provide 3 nozzles per row, delivering 11.7 total gallons of spray solution per acre at 40 psi. After the application of Fulfill (all replicates), Curacron alone (1st and 3rd replicate) and Curacron + Fulfill + Organosilicant (3rd replicate and one-half of 2nd replicate), it rained hard on the treatment plots. As a result, the spray materials were probably washed off the plants. Also, Curacron foamed badly and sprayer pressure was completely lost; the pressure bypass and agitation system were then turned off to eliminate foaming. Thereafter, all treatments were reapplied on those plots that were sprayed before the rain. Approximately 30 h post-treatment, it rained again 0.38 inches which probably washed the aphids off of the leaves to some degree. Post-treatment aphid counts were made at 3, 7, 13, and 17 DAT. Test plots received additional rainfall on 10 Aug (1.75") and 19 Aug (1.85").