Volunteer corn begins during corn harvest when individual kernels drop, overwinter and germinate in the spring. This can have unfortunate consequences for corn rootworm management.
Impact on Crops
Volunteer corn can reduce yield potential in soybean fields and can serve as a bridge to potential problems in corn the following season. Corn rootworm can survive on volunteer corn in a soybean field and lay eggs in the soil. If corn is planted in that same field the following season, those corn rootworm eggs can hatch and larvae can cause damage to corn roots.
Furthermore, volunteer corn from a Bt-traited crop can express reduced levels of one or more Bt proteins. Corn rootworm larvae that feed on it may be exposed to sublethal doses of Bt protein, which can contribute to resistance development over time, making the insect even more challenging to combat.
Solution for the Following Year
Early action against volunteer corn is ideal. The nodal root system needed for corn rootworm larvae to mature begins at the V6 stage, so it is best to eliminate volunteer corn before it reaches this stage. Additionally, early management is usually more affordable and may help prevent yield loss come harvest.
In soybean fields where volunteer corn is not managed effectively, planting products with Bt traits like SmartStax® technology the following year can help combat corn rootworm that may have overwintered.