Temperature – High temperatures this past week have helped Growing Degree Day values catch up to around the 10-year average in most regions. Peterborough and Kemptville remain marginally behind. Temperatures are expected to cool over the next week across Ontario. Carrot Rust fly thresholds have been triggered in Chatham-Kent and Norfolk counties, while Essex County is past the first threshold range. Many regions have reached the first carrot weevil threshold with some having already surpassed the first generation values. Onion and seedcorn maggot thresholds have been triggered in all regions except Sudbury. Aster Leafhooper thresholds have been reached in Essex, Chatham-Kent and, Norfolk counties. Degree day data for each region is shown below.
Rainfall – All regions continue to lag behind 10-year average values. There is a chance of some rain across Ontario in the next week but Sudbury could see showers throughout. Precipitation data for each region is shown below.
Asparagus – Harvest is underway, these are peak weeks for spear production. Scout for Phytophthora symptoms which may be confused with frost damage from last week, and be on the lookout for Asparagus Beetle and Cutworms.
Beans & Peas – Peas have reached the 2-3 node stage, some peas saw minor frost damage last week. Some peas have begun flowering in some areas.
Brassica Crops – Most transplants are bouncing back from the frost and are putting up new leaves. Flea beetles are active and being observed in high numbers in Southwestern Ontario. Seedcorn maggot has reached the threshold for first generation emergence.
Celery – Celery transplants are establishing well. The threshold for aster leafhopper has been reached in Essex county while nearly every county has had enough growing degree days for tarnished plant bug.
Cucurbits – cucumber beetle came out of dormancy in large numbers this week and has been found on squash and watermelon: prioritize scouting of summer squash and any propagated or planted pumpkin as these are highly attractive to these beetles.
Garlic – Leek moth is active in all growing regions that it has observed in moderate levels in the past. If counts are lower next week compared to this week, the bulk of the emerged larvae will be targeted if an insecticide is applied 7 – 10 days after peak trap capture. Garlic is showing tipburn across all regions of the province.
Onions – Earliest direct seeded onions are at the third leaf stage while the majority of fields are in the 1st leaf stage. Transplant fields are overcoming frost damage from the middle of May. Onion and seedcorn maggot flies have reached their threshold for the first generation emergence in all counties except for Sudbury.
Sweet Corn – Early planted sweet corn saw some frost damage last week.
NOTE: Data as of May 27th, 2020
Pest Degree Day Forecasting
|Pest||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: