Evaluation of Soil Insecticides on Continuous Corn in Ohio, 1994

Abstract

Abstract Soil insecticides were evaluated for stand protection and rootworm control in 2 tests conducted at the OARDC Western Branch Field Station near South Charleston. Each test included 14 treatments compared to an untreated check treatment on reduced tillage plots that were 140 ft in length and 2 rows wide at 30 inch row spacing. A RCBD was applied to both tests with 8 replicates in Test 1 and 4 replicates in Test 2. Plots represented in 4 replications of Test 1 and all replications of Test 2 were preceded by a trap crop of late planted corn. The remaining 4 replications of Test 1 were preceded by 1st year corn that was adjacent to continuous corn. Planting time granular treatments were applied as a band prior to closure by the press wheel or in-furrow using a 2 row John Deere 7000 planter equipped with either Noble granular applicators or computer controlled Smartbox granular applicators. Planting time or post emergence applications of liquid formulations were applied as banded or broadcasted treatments with a boom sprayer equipped with flat spray nozzles and calibrated to deliver desired dosages at 3 mph. All treatments of Test 1 were applied 28 Apr at planting. In Test 2, granular treatments were applied 11 May at planting and post-emergence liquid treatments were applied 3 Jun. Planting and application of the liquid Fipronyl WG treatment was delayed to 18 May due to weather conditions. Treatments were evaluated 7 Jun for stand loss with stand counts of total and injured plants (predominantly cutworm injury) per 100 row feet when corn was predominantly at 5th or 6th leaf stage. Root ratings were conducted 6 Jul on 5 plants per replicate. Lodging was evaluated 19 and 21 Jul by examining 100 plants per replicate. Grain yields were determined by machine harvest of total plots during mid Oct.