Armyworm Control in Barley, 1979

The test site was located in Queen Anne's County, Maryland. Barley at time of treatment May 28 was near maturity. Larvae were in 3rd and 4th instars and precounts May 25 averaged 11 larvae/6 ft of row. Treatment plots 15 × 20 ft were arranged in a randomized complete block design with 4 replicates. Sprays were applied with a “back-pack” hand held CO2 pressure sprayer calibrated to deliver 10 gpa at 40 psi. Toxaphene is the most widely used material for armyworm control and is the standard in this test. Post treatment counts were taken May 28. Two random 3 ft of row counts were made between the 2 middle barley rows in each plot and the number of larvae recorded. At the time of treatment, the economic threshold of 2/ft of row were exceeded in all plots.