What to consider for your corn rootworm management plan
Corn rootworm (CRW) management plans need to be tailored to your acres. For example, different strategies work better for continuous-corn vs. rotated acres. And acres with high CRW pressure need to be managed differently than acres with low pressure.
Keep in mind that all CRW management strategies should be adjusted based on:
- Local pest pressure
- Historical field problems
- Regional variants present
- Environmental conditions
- Economic factors
Key Corn rootworm management practices for continuous-corn acres
Continuous-corn acres are generally considered higher risk and should be managed with a mix of the following practices:
- Scouting: Conduct regular monitoring throughout the season.
- Bt Trait Selection: This is more crucial, as continuous-corn acres often need multiple modes of action to achieve control.
- Insecticide Use: You may need soil insecticides annually.
- Resistance Management: Rotating control methods in continuous-corn acres is more crucial in order to avoid resistance.
Corn rootworm management practices for rotated acres
Rotated acres are generally considered lower risk, but still require monitoring due to:
- Extended diapause in NCRW
- Soybean variant of Western corn rootworm (prevalent in Illinois and Indiana) that lays eggs in soybean fields, which then emerge the following year if corn is planted
Key Corn rootworm management strategies in rotated acres
- Scouting: Evaluate in-season pressure with sticky traps and root digs and watch for signs of extended diapause.
- Bt Trait Selection: Depending on the level of CRW pressure, a hybrid with a Bt trait may be necessary.
- Early control: Consider a soil-applied insecticide at planting.
- Volunteer corn management: Volunteer control in soybean acres is important to prevent CRW beetles from producing eggs for the following season.
Management practices for high Cornroot worm pressure areas
Managing corn rootworm requires a specialized pest management approach over several years. Regular monitoring and understanding of local population dynamics are critical for long-term economic solutions.
Corn rootworm trait stacks
Consider trait stacks with multiple modes of action against CRW. Rotating management options and alternating between modes of action can help minimize resistant rootworm populations which is especially important on continuous-corn acres.
Crop rotation
Rotation to a non-crop host can disrupt the life cycle of CRW, even in areas with extended diapause. Rotating to a non-host crop such as soybeans will quickly lower CRW field populations and is highly effective in reducing the risk of insect adaptation.
Management practices for low Corn rootworm pressure areas
- When planting first-year corn in areas without the Western CRW variant or Northern CRW extended diapause: consider a non-CRW traited hybrid with or without Force soil-applied insecticide.
- When planting first-year corn in areas with Western CRW variant or Northern CRW extended diapause: consider a CRW traited hybrid or a non-CRW traited hybrid with Force soil-applied insecticide.