Corn Rootworm Granular Insecticide Performance, No Till Vs Tilled, 1994

Abstract

Abstract The test plot was planted on 4 May. Banded (7 inch) and in-furrow planting time treatments were applied with a cone-belt distributer mounted on a John Deere Maxemerge equipped with incorporation tines. The seeding rate was 18,000 seeds/acre on 30 inch rows. Soil type was silty clay loam (OM > 3%, pH 6.5). Previous crop was late planted corn planted as a trap crop. The experimental design was a RCB with 4 replications, each treatment a single row 50 ft long. One-half of each treatment block was double disked (tilled) prior to planting (10 to 20% residue cover remaining). The other half was undisturbed (no till) (70-80% residue cover remaining). Treatments were randomized within each one-half block. Preplant anhydrous ammonia was applied at the rate of 90 lb per acre prior to planting. Five randomly selected roots from each replication were rated on the Iowa State 1-6 scale (1, no damage; 6, 3 or more nodes pruned to within Wi inch of the stalk). Twenty roots were rated for each treatment. The roots were dug and rated on 15 Jul. Soil moisture was adequate at planting. Rainfall was adequate through rating time.