Given prospective corn prices, a low-cost strategy is simply to plant hybrids with good root scores. The second option is to change rotation and plant another non-host crop instead of corn. A second year out of corn will largely eliminate the corn rootworm population, although a very small proportion of third-year eggs might remain. This approach presents a dilemma for most producers, since two years of soybean can aggravate other pest problems. The third group of options is the use of a corn rootworm insecticide in rotated corn.
Growers can select among granular insecticides, liquid insecticides or seed treatments.
Equipment, logistics, and availability will determine what might be compatible with each operation. If your planter has insecticide boxes, this option provides the opportunity to reduce costs. 3G provide control equivalent to labeled rates. Consult the company representatives to see what rates they are willing to stand behind and calibrate. Reduced rates of less-consistent granular insecticides, e.g., Lorsban 15G and Thimet 20G, are not recommended.