Temperature – All counties are meeting or surpassing their 10 year GDD averages. Temperatures are expected to rise into the mid- to high- twenties at the beginning of next week before dropping again slightly towards the end of the week.
Precipitation – All counties saw some rainfall over the past week though most are behind the 10 year average. Kemptville however has now greatly surpassed their 10 year average rainfall for May. Rain is forecasted for tomorrow in most regions except Sudbury which may see rainfall later. There is also the risk of thunderstorms in some areas.
Brassica Crops – Flea beetles, swede midge and cutworms are active. Seedcorn maggot has reached the threshold for first generation emergence and cabbage maggot will be emerging soon in most regions across the province and is likely already active in Essex and Chatham-Kent. Diamondback moths and imported cabbageworms are likely to be observed very soon. Pull up wilted plants and inspect roots for larvae.
Celery – Transplants are establishing well, and most fields have been planted across Southwestern Ontario. The threshold for aster leafhopper has been reached in Essex, Chatham-Kent, Norfolk, Huron and Kemptville, Sudbury and every county has had enough growing degree days for tarnished plant bug.
Garlic – Plants showing tipburn earlier in the season are starting to look better as the newer leaves emerge. Scout for leek moth by looking for green frass and ragged leaves. Insecticides should be applied ~7 days after peak trap capture. Wireworm, cutworm and seedcorn maggot damage has been observed.
Onions – Earliest direct seeded onions are at the third leaf stage while the majority of fields are in the flag or 1st leaf stage. The cool weather has made germination rates variable in many fields. Transplant fields are establishing well. Onion and seedcorn maggot flies have reached their threshold for the first-generation emergence in all counties except for Sudbury and damage from early season activity has been observed. Dig up wilted plants and inspect roots for onion maggot larvae.
Tomatoes – planting is about 75-80% for processing tomatoes and fresh market tomatoes are continuing with their staggered planting schedules. Be sure to keep and eye out for early season insect pests like black cutworm, wireworm and Colorado potato beetle. These pests are becoming more of an issue with the loss of some key insecticides and early detection is key to managing them effectively.
Pest Degree Day Forecasting
*NOTE: Data as of May 25, 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: