Research Specialist, Agrobiology Research, Inc., Memphis, TN
Research Manager, Helena Chemical Company, Memphis, TN
Pages: 14 Published: Jan 2003
Research was conducted in 2002 to evaluate the effect of various spray application parameters on the efficacy of the insecticides indoxacarb and spinosad and the cotton defoliants ethephon/cyclanilide and carfentrazone-ethyl. Laboratory results indicated that an adjuvant was required for air entrapment in sprays from venturi-type nozzles and that defoamer present in the surfactant formulation only slightly reduced the amount of air entrapped in the spray. The amount of air entrapped in the spray differed among the various nozzles, with the ITR80-01 nozzle entrapping the most air and the ULD120-015 nozzle entrapping the least. With both insecticides, the adjuvants HM8802-A or AB0201 decreased the amount of leaf eaten by larvae (leaf damage) compared to leaf damage when insecticides were applied with the hollow cone nozzle. All venturi-type nozzles reduced the amount of leaf damage compared to the hollow cone nozzle. The amount of air entrapped did not appear to be related to efficacy. The drop-nozzle system typically had the least amount of leaf damage of all the spraying systems evaluated. With both defoliants, all of the adjuvants enhanced cotton defoliation when applied using hollow cone nozzles. Ethephon/cyclanilide-enhanced defoliation of cotton was greater when applied through venturi-type nozzles than through hollow cone nozzles at the final evaluation. Carfentrazone-ethyl-enhanced defoliation of cotton was similar when applied through venturi-type nozzles or hollow cone nozzles. The drop-nozzle system enhanced cotton defoliation similar to that from venturi-type nozzles.
defoliant, insecticide, air entrapment, nozzle, adjuvant, air entrapment, venturi nozzle
Paper ID: STP11206S