Control of Grasshoppers on Rangeland with Carbaryl, 1982

A new FR formulation of carbaryl was applied at 4 dosage rates (4, 5, 6, and 8 oz ai/acre) to square 40-acre plots replicated 4 times near Douglas, WY on Jul 21-23. The primary objective was to compare 2 basic formulations; the secondary objective was to evaluate effects of replacing toxicant with ‘PA-3’, a confidential anti-evaporant that theoretically could also act as an attractant, feeding stimulant, or feeding arrestant. All treatments were applied in 20 oz of liquid/acre, comprised of 4 oz of water, plus either 16 fl oz of FR in the case of the highest dosage rate or 16 fl oz of a mixture containing FR diluted with sufficient PA-3 to provide the 4, 5, and 6 oz dosages. These treatments were compared to a standard treatment of 16 fl oz of Sevin 4.0 Oil (8 oz ai) diluted with 4 fl oz of diesel oil/acre. All treatments were applied with a Cessna Ag-Husky aircraft at 28 psi through Spraying Systems 0-5 nozzles and no. 45 course swirl plates. Flight speed was 125 mph, flight height was 100 ft, and swath width was 100 ft. Nozzles were directed straight down for the 6 and 8 oz FR treatments, and were directed slightly backwards for the other 3 treatments. Actual application rates were calculated to range from 19.1 to 20.2 fl oz/acre.