Corn Rootworm Insecticide Screening, 1997

Abstract

Abstract The test plots were planted on 9 May. Seven-inch banded (TB/P) and in-furrow (IF/P) planting time treatments were applied with a cone-belt distributor mounted on a John Deere Maxemerge equipped with incorporation tines. Regent 4 SC and 80 WP treatments were applied in-furrow at planting (MT/P) with microtubes at a 1-gallon solution per acre. Cultivation treatments (B/C) were applied over the row on 19 Jun with the cone-belt distributor mounted on a hand-powered bicycle-wheel applicator. The entire plot was cultivated immediately after application of the 19 Jun treatments by a tractor-mounted cultivator. The seeding rate was 19,000 seeds/acre on 30-inch rows. Previous crop was late planted corn as a trap crop. The field was disked twice prior to planting. Preplant anhydrous ammonia was applied at the rate of 90 lb/acre prior to planting. Approximately 20% corn stalk residue was left after field preparation. The experimental design was a RCB with four replications, each treatment being a single 47-ft-long row. Five randomly selected roots from each replication were dug and rated on 24 Jul on the Iowa State 1-6 scale (1. no damage; 6, 3 or more nodes pruned to within 1 1/2 inch of the stalk).