Insecticide Effects on Potato Leafhopper and Nabids, 1982

Insecticides were applied to the second cutting of alfalfa planted in the spring near Blacksburg, VA, using a CO2-powered boom sprayer with 19 gal water/acre 18 lb psi. Treatments were replicated 5 times in 50 ft x 50 ft plots in a randomizer block design. Insect samples consisted of 10 pendular sweeps per plot using a 15 in net. Insect counts were transformed to square root of (X + .05) prior to analysis of variance. Treatments were applied Jul 14 when 2nd growth alfalfa was 6 in tall, the mean nymphal leafhopper density estimate was 0.9 per sweep, and the pretreatment adult leafhopper density estimate was 3.4 per sweep. No yield or forage quality samples were taken because of high intraplot variability in plant growth.