Apr 26, 2024
Best Practices Recommended for the Control of Corn Leafhoppers
Author: Michael Cordonnier/Soybean & Corn Advisor, Inc.
Corn leafhoppers (Dalbulus maidis), which are responsible for transmitting corn stunt disease, are causing significant problems for corn farmers in Argentina and Brazil. In infected fields, yield losses can vary from as little as 5% to as much as 100%. There is no registered treatment for the disease once a plant is infected, so it is imperative to implement best practices to control the insects before they can infect corn.
Bayer Crop Science in conjunction with the Brazilian agricultural research service, Embrapa, are recommending the following practices for Brazilian farmers to best control corn leafhoppers.
Pre-Plant
- Elimination of any volunteer corn: Volunteer corn plants between growing seasons can function as a refuse for corn leafhoppers. Volunteer corn plants need to be eliminated in previously harvested fields, along roadways, or near storage or transportation facilities. Corn leafhoppers can overwinter in many types of grasses, but the elimination of volunteer corn is the easiest way to hold down insect populations.
- Corn hybrid choice: Chose corn hybrids with the greatest degree of tolerance to corn stunt disease. This will not eliminate the disease, but it will help to minimize the losses.
Planting:
- Seed treatment: Corn seed should be treated with an approved systemic insecticide. This can be 90% effective in protecting the young seedlings.
- Maintain distance from infected fields: Corn leafhoppers migrate from more mature corn to less developed corn, so it is important to maintain the greatest distance possible from known infected fields.
- Narrow planting window: Corn should be planted in the narrowest window possible to minimize the movement of corn leafhoppers from more mature corn to less developed corn.
- Monitor insect populations: If corn leafhoppers are detected on young seedlings, an approved insecticide should be applied as soon as possible.
- Manage insect populations: An approved insecticide should be applied if leafhoppers are present at the V2 stage. Additional applications should be applied within seven-day periods at V6 and V8 stages.
Harvest and post-harvest:
- Harvesting: It is important that the corn is harvested at the correct moisture and with a well-adjusted combine to minimize seed loss that could later germinate and function as a refuse for the insect.
- Transportation: Corn should only be transported by vehicles that minimize seed loss during transportation to avoid volunteer corn along roadways and near storage or transportation facilities.
- Crop rotation: Crop rotations is essential to minimize leafhopper populations. If possible, successive corn crops should not be planted in the same field.
Bottom line: There is no one definitive solution for the control of corn leafhoppers. Any hope of controlling the insect will depend on farmers using best practices and integrated pest management.