Temperature: Temperatures continue to rise over the weekend before dropping back into the teens next week. Most counties are at or marginally behind their 10-year GDD averages with the exception of Huron and Durham counties which are slightly ahead. The pest threshold has been reached for onion maggot in Essex and seedcorn maggot is now at threshold in Essex, Chatham-Kent and Norfolk counties.
Precipitation: Most counties may see some rain over the weekend with the possibility of thunderstorms. Most did not experience any significant rainfall over the past week.
*Note: The 10-year average GDD calculation has changed to better reflect the current weather trends. Last week’s GDD graphs have been updated.
Brassica crops – Transplanting is well underway. While it has not been warm enough for cabbage maggot fly to reach it’s first generation growing degree threshold in any county, seedcorn maggot fly is active in most regions. Dig up wilted transplants and inspect roots for insect damage. If you were unable to attend the 2022 Brassica Crops IPM Scout Training workshop, a recorded version can be viewed below:
Celery – Transplanting is underway across the province. Ensure that there is adequate moisture to get good crop establishment.
Garlic – Plants are at an average of 4-7 leaves. Leek moths are active in most regions with the warm night temperatures and will be laying eggs over the next week. Seedcorn maggot damage has been observed in SW Ontario and has reached its first generation threshold in Essex, Chatham-Kent and Norfolk counties. Dig up plants that have wilted leaves to look for seedcorn maggot larvae, wireworms or millipedes.
Onion – Onions are still being transplanted and direct seeded onions planted last week are starting to emerge in fields with adequate soil moisture. The threshold for the first generation of onion maggot has been reached in Essex county.
Pest Degree Day Forecasting
*NOTE: Data as of May 11, 2022
|County||Carrot Rust Fly||Onion Maggot||Carrot Weevil||Aster Leafhopper||Tarnished Plant Bug||Cabbage Maggot||Seedcorn Maggot||European Corn Borer|
|THRESHOLD||329-395, 1399-1711||210-700, 1025-1515||138-156, 455+||128+||40+||314-398, 847-960, 1446-1604||200-350, 600-750, 1000-1150||See legend below|
*- Bivoltine region for ECB. First Peak Catch: 300-350 DD, Second Peak Catch 1050-1100 DD
**- Overlap region for ECB. First Peak Catch: 300-350 DD Second Peak Catch 650-700 DD, Third Peak Catch 1050-1100 DD
***-Univoltine region for ECB. Peak Catch 650-700 DD
Use these thresholds as a guide, always confirm insect activity with actual field scouting and trap counts.
Select a region below for the latest weather, crop and pest degree day information: