Tag Archives: Sweet Corn

Corn Earworm and Late Planted Sweet Corn

Corn earworm pressure often increases as we head into September. With turbulent weather patterns originating in the Gulf of Mexico, flights of airborne moths are generally quite high.  As the tradewinds mix with the cooler air of the great lakes, these high populations are dropped into Southern Ontario.  Any sweet corn at the green silk stage is highly susceptible to corn earworm infestation.

For earworm control, cover green silks with an insecticide such as Coragen or Voliam Express.  Avoid insecticides from the pyrethroid family.  Corn earworm are known to be resistant to the pyrethroids.  Lannate TNG is a good rotational partner for Coragen and Voliam Express.

Heliothis trap for corn earworm monitoring

2017 Growing Degree Days for European Corn Borer – June 24, 2017

Bivoltine: The first generation of European corn borer adults are just past peak flight levels.

Overlap: The overlap areas will experience sustained ECB pressure as the bivoltine moths are at peak flight and the univoltine moths are now emerging.  Pest pressure in both areas is expected to increase over the next week.

Univoltine: In the univoltine areas (Eastern Ontario) first flights of moths are beginning to emerge.

Scout all sweet corn fields regularly as soon as the tassel begins to emerge from the plant. For more information on European corn borer management in sweet corn, visit our Ontario CropIPM pages

Note: we are experimenting with this new format for communicating growing degree days for European corn borer. As we refine the techniques the quality of the charts below will improve. Thank you for your patience.

2017 Growing Degree Days for European Corn Borer – June 19, 2017

The first generation of European corn borer adults are at peak flight in the Bivoltine area. In the overlap areas, the emergence of the univoltine strains is beginning as well as the peak flight of the first generation bivoltine strains.  Pest pressure in both areas is expected to increase over the next week.  In the univoltine areas, first catch of adult ECB moths can be expected within the next week.

Note: we are experimenting with this new format for communicating growing degree days for European corn borer. As we refine the techniques the quality of the charts below will improve. Thank you for your patience.

Delegate Insecticide label expanded via Minor Use Program for control of additional insects on several crops in Canada

J. Chaput, OMAFRA, Minor Use Coordinator, Guelph

The Pest Management Regulatory Agency (PMRA) recently announced the approval of URMULE registrations for Delegate Insecticide for control of several additional insect pests on several crops in Canada. Delegate Insecticide was already labeled for use on a number of crops in Canada for control of insects. Continue reading Delegate Insecticide label expanded via Minor Use Program for control of additional insects on several crops in Canada

Corn Earworm Update – August 29, 2014

Based on information from the website insectforecast.com, it appears the risk of corn earworm flights into Southwestern Ontario has increased significantly over the past week. The University of Illinois Fruit and Vegetable News also reports increased trap counts this week.

Female earworm moths lay their eggs on sweet corn at the green silk stage.  One female can lay up to 100 eggs per night over a 10 night period.  The eggs incubate for 2- 10 days, depending on the temperature. After the egg hatches there is a narrow window of opportunity to control this pest before it enters the protection of the husk.

During periods of potential corn earworm activity, apply a corn earworm insecticide at 50-60% silk, with a second insecticide application 4 days later. Note: corn earworm populations may have a high degree of resistance to pyrethroid insecticides. The level of resistance varies greatly from year-to-year.

Pheromone trapping is an excellent tool to help monitor localized populations in specific sweet corn fields. For more information on trapping, visit Ontario CropIPM.

Two different types of pheromone traps used for corn earworm. The heliothis trap (rear) and the hartstack trap (front).
Two different types of pheromone traps used for corn earworm. The heliothis trap (rear) and the hartstack trap (front).

Use of Sandea Herbicide in Tomatoes, Vine Crops, and Peppers and Permit in Sweet Corn

Darren Robinson, Weed Researcher, Ridgetown Campus – University of Guelph

Sandea and Permit are Group 2 herbicides that are taken up by roots and shoots and are systemic in the plant.  The herbicides will translocate to the new growing tissues, and if applied to a sensitive crop or weed, it will cause stunting, chlorosis (yellowing) and may even delay maturity of sensitive species.  These herbicides are particularly useful for control of preemergence control of common lamb’s-quarters and postemergence control of yellow nutsedge.  They have also provided good control of common ragweed and redroot pigweed.  The labels should be consulted before use in all cases, and are available at http://www.uap.ca/products/products.htm.

Continue reading Use of Sandea Herbicide in Tomatoes, Vine Crops, and Peppers and Permit in Sweet Corn