Alfalfa Weevil and Pea Aphid Control on Alfalfa in Washington, 1977

Eight insecticides were evaluated at Badger Basin in Kittitas County. These materials were applied to 8 x 14 ft plots in a randomized complete block design with untreated checks in 3 replications. Sprays were applied on June 7, 3.5 weeks prior to harvest, with a compressed air plot sprayer mounted on a bicycle-wheeled carriage, using 40 psi pressure and applying 32.5 gal/acre. The plots were evaluated on June 16 by taking 25 individual stems of alfalfa from each plot and counting the weevils and aphids present. A 2nd evaluation was taken on June 29 using a sweep net. Pea aphid densities were categorized using a rating scale of 1 to 7 (1 = no aphids, 2 = 1-10, 3 = 10-30, 4 = 30-50, 5 = 50-100, 6 = 100-200, 7 =>200).