Alfalfa, Evaluation of Insecticides Against Alfalfa Weevil, Pea Aphid, and Meadow Spittlebug, 1983

Treatments were applied 6 May, using a tractor-mounted hydraulic sprayer with a boom length of 20 ft at 28 gal/acre and a pressure of 20 lb/in2 ; plant height averaged 7 in. Treatments were replicated three times in a randomized complete block design on plots measuring 22 by 40 ft. Sampling consisted of one, 10-sweep sample per plot using a standard 15-in. diam. sweep-net swung in a 180° arc. Samples were collected weekly for 4 weeks and mean values compared by ANOVA. Total accumulative precipitation for 1, 2, 3, and 4 weeks posttreatment was 0.10, 2.29, 3.20, and 3.79 in., respectively. The combination of alsystin (an insect growth regulator (IGR)) and Baythroid (a synthetic pyrethrin) was included in these trials primarily to evaluate efficacy of a pyrethroid at very low rates AI plus an IGR for use in IMP programs for alfalfa weevil where protection of beneficial insects from chemical treatments is desired.