Sorghum Greenbug Control, 1976

Plots were arranged in a randomized complete block design in Clay County, Nebraska. Irrigated plots, summarized in Table 1, were 2 rows, 45 ft long (30 in centers), with 5 replications. Plots were separated by 1 untreated row on each side and a 15 ft grass driveway on each end. Irrigation water was applied with towline sprinklers. All other plots were under dryland conditions and were 2 rows, 30 feet long (30 in centers). Plots were separated by 1 untreated row on each side and 1, 4ft alley and a 15 ft wide untreated strip at each end. Dryland experiments were replicated 4 times except for the recommended insecticide test (Table 2) which was replicated 5 times. Granular insecticides were applied with a Noble metering device mounted on the planter or a bicyclewheeled carriage. Liquid insecticides were applied with a compressed air plot sprayer mounted on an International Harvester 140 tractor. Relative effectiveness of treatments was evaluated by counting live greenbugs on 10 plants selected at random from each plot until July 19 when 5 plants per plot were examined. Percent control was calculated by Abbott's formula.