Greenbug Control with Magnum Seed Treatment on Winter Wheat, 1986

Abstract

Abstract Winter wheat plots were planted near Nunda, S. Dak. (loam soil type) on 12 Sep with a grain drill with double disk openers. Thimet was applied to the seed furrow via a grass seeder attachment on the 4iain drill. Plots (1.8 × 15 m) were planted in a randomized complete block design with 4 replications. Precipitation following planting was extreme; 12.8 cm of rain fell during the first week after planting. On 2 Oct a 0.9- × 0.9-m cage was placed over a portion of each plot, and greenbugs were released into these ;ages and allowed to infest the wheat plants (2-leaf stage). The greenbugs were obtained from the Northern Grain Insects Research Laboratory in Brookings, S. Dak. (R. Kieckhefer). Each cage received all the greenbugs that were infesting a single sorghum plant that had been growing in the greenhouse. The average number of aphids infested/cage was 350. On 10 Oct the number of aphids/plant was counted on 10 plants in each plot (40/treatment). At this time, the plants were in the 2- to 3-leaf stage. Aphids were again counted on 20 Oct (10 plants/plot), and the plants at this time were in the 3- to 4-leaf stage. Analysis of covariance was used to account for differences in initial infestation levels.