ABSTRACT
A season-long study of aerial application methods for controlling sweetpotato whitefly in furrow-irrigated cotton was conducted near Maricopa, Arizona in 1993. Similar research in 1992 showed that aerial systems that caused increased air velocity and turbulence in the crop canopy when spray was being deposited resulted in increased deposits on the underside of leaves where whiteflies locate. Application treatments in the 1993 studies included rotary atomizers, winglets, Trumpet nozzles, and CP nozzles. Spray deposit characteristics were measured on water-sensitive paper attached to leaves at top and mid canopy locations each time the field-scale treatments were applied. Results of these studies show that treatments that produce and deposit droplet spectrums with volume median diameters in the 100 mm range improve control of sweetpotato whitefly in cotton.
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