Prolonged dry conditions of soil may limit chemical release. Alkaline soils cause insecticides to deteriorate faster than neutral or slightly acid soils. High populations of microorganisms may accelerate breakdown of some insecticides in certain soils. High soil organic matter content may reduce efficacy. Control with most insecticides will be reduced if they are applied in narrow bands, if granules are not covered with soil, or if wind blows granules off the rows.
Application is less than the labeled or suggested rates.
All of these factors are of greater importance with early planted corn. The longer granules remain in the soil before rootworm eggs hatch, the less effective the insecticide will be in controlling the larvae. Rates of Application Nebraska corn rootworm soil insecticide dosage rates are given in ounces per 1,000 feet of row. I for the amount of insecticide formulation needed per acre using various row spacings. 5.89 6.24 6.66 Chemical Rotations Evaluate soil insecticide performance annually by comparing corn root ratings in treated and untreated areas.