First Generation European Corn Borer Control in Southeast Pennsylvania, 1985

Abstract

Abstract This commercial field test was conducted in cooperation with Marty Greenleaf of Green Acre Farms near Kirkwood, PA in southeastern Lancaster County. A 4-acre field, which was corn in 1984, was no-till planted on 30-inch centers with ‘Todd M75’ field corn on 26 Apr ‘85 with Counter 15G soil insecticide at 8 lb/acre When corn was at the 7 to 9-leaf stage (38-inch extended leaf height), scouting for first generation ECB “shot-hole” feeding damage (20 consecutive plants in each of 5 randomly selected areas of the field) indicated that 41% of the plants were infested. Larvae were first and second instar with an average 2.0 larvae/plant. In addition fresh egg masses were found on several plants. On 6 Jun ‘85 Lorsban 15G at 6.5 lb/acre (1.0 lb (AI)/acre) was applied using a small-plot Gandy air-spred granular applicator (compliments of Gandy Corp) pulled behind a tractor. Granules were applied directly over the whorls with 3 rows treated the length of the field and 3 adjacent rows treated in the return trip across the field. This exact procedure was replicated 3 times in the field (totalling about 0.7-0.8 treated acres). Treated strips were separated by 6-row non-treated strips. On 10-11 Jul ‘85 the treatments were evaluated by dissecting 10 plants (5 consecutive plants from each of 2 rows) from 3 random sample sites within each treated strip and 3 non-treated strips, and counting the no. of live corn borer larvae and empty tunnels caused by borer feeding. A yield evaluation was made on 25 Sep ‘85 by commercially harvesting, with the farmer‘s 6-row combine, the entire length of each treated strip and each adjacent non-treated “check” strip. Grain from each strip was weighed separately (using a weigh wagon furnished by Dow Chemical), and % moisture was determined with a moisture tester.