Effects of Insecticides on Alfalfa Weevil, 1976

Chemicals were applied Apr 22'76, to Kanza alfalfa in a randomized complete block design with three replications. Plots were 6 × 15 ft. Spray concentrates were applied in 20 gal water per acre at 40 psi. Weevil larvae were sampled 7 days later. Fifteen stems were cut at random from each plot and data were expressed as larvae per stem. Larvae also were sampled one day before the first cutting (May 20) with a 15-inch sweep net. Weevil damage to the alfalfa was expressed by 1= least to 9 = most and by plant height May 19. Plots were harvested 4 times and yields (tons per acre dry weight) were calculated as percent of control. All plots were sprayed with Furadan 4F 0.5 lb a.i./A one day after first cutting.