Evaluation of Systemic Insecticides for Control of Insect Pests of Soybeans, 1981

Soybeans were planted Jun 8 with a conventional 4-row planter (John Deere Model 71) equipped with Gandy granular insecticide applicators. Except for the Furadan treatments which were applied in the furrow, all other treatments were applied in a 14 inch band over the seed furrow, behind the press wheel. Two drag chains were attached behind the press wheel of each planter. Plots consisted of 8 rows (4 rows of treated soybeans buffered on either side by a single row of untreated soybeans and a single row of untreated Earilwax wax bean), 80 ft long with 30 inches between rows, arranged in a randomized complete block design with 4 replications. The center 4 rows of York soybeans served as the record rows. Soil was classified as a ‘Bertie’ silt loam and the soil temp at the time of planting was 70°F at the 6 inch depth. Twenty 1st to 2nd instar si Iverspotted skipper larvae with’ accompanying nest were artificially introduced into the plots by pinning them to 20 separate plants in each plot on Jun 23. The number of surviving siIverspotted skipper larvae was recorded 3 days later (June 26). Natural populations of Mexican bean beetle and Japanese beetle were monitored throughout the season. At late pod-fil, 20 plants were selected at random following an “x” pattern in each plot. Each plant was rated visually to the nearest 10% defoliation. Yield data were taken from 2 rows, 16 ft long, in the center of each plot. Yields were adjusted to 13% moisture and reported in bu/acre.