Planting-Time and Rescue Applications of Furadan 4F for Control of Northern and Western Corn Rootworm Larvae in South Dakota, 1994

Abstract

Abstract Cornfields located near Aurora, Cavour, and Garretson in central and east-central SD were chosen for this study. The experiment was conducted to compare the efficacy of traditional (banded or in-furrow) planting-time insecticide application methods with cultivation-time rescue treatments for controlling corn rootworm larvae. Experimental design was a RCB with 4 replications. Individual treatment plots consisted of single 15.2-m long rows spaced 96.5 cm apart. Pioneer IR-3751 (100-day) corn seed was planted at approximately 23,000 kernels per acre at each location. Planting-time granular formulations were applied using Noble metering units mounted on a specially-adapted Kinze 4-row corn planter, and all units were calibrated on the planter prior to insecticide applications. Banded granular treatments were applied in an 18-cm swath in front of the furrow-closing wheels, and incorporated by the wheels and drag chains. All planting-time applications (banded and in-furrow) consisted of directing insecticides immediately between double-disk furrow openers and into the open seed furrow. Post-emergence banded applications of Furadan 4F were placed over the row in 18- to 20-cm swaths using a single-nozzle (Teejet 8003 flat fan) boom. Broadcast ("Broad") liquid treatments were applied with a 1.8-m boom-equipped with 4 Teejet 8003 flat fan nozzles spaced 46 cm apart. Liquid formulations (planting-time and post-emergence rescue) were applied using a CO2-powered canister spray system calibrated to deliver 20 gpa at 3 mph. All post-emergence treatments were applied at cultivation time, and those that received cultivation following application were incorporated using a 2-row John Deere cultivator. Five roots per replicate were dug, washed, examined for feeding damage and rated using the Iowa 1 to 6 scale. Data were analyzed with SAS’s General Linear Models procedure and means were compared using DMRT.