Welcome back to the next VCR Report for 2023! With only a few days of May remaining, many counties are behind in their monthly totals for precipitation compared to their ten year average. Most counties are close to their ten year average when it comes to degree days with a base of 5°C.
Brassica Crops – Many areas received temperatures at or below -4°C last week which has resulted in tip dieback of some older leaves. The degree day threshold for cabbage maggot emergence has yet to be reached in any county, while seedcorn maggot is active across most of the province. Observe the roots of wilted transplants and look for wireworms or cutworm larvae. Check stunted plants for wirestem and scout for flea beetles, diamondback moths, imported cabbageworms and cutworms.
Garlic – Plants showing tip burn earlier in the season are starting to look better as more new leaves emerge. Scout for leek moth by looking for green frass and damaged interior leaves. Insecticides should be applied ~7 days after peak trap capture. The Garlic Growers Association of Ontario is hosting their annual field day June 10th. Equipment from multiple suppliers will be on display, along with products from fertilizer and pest control product suppliers. The agenda includes a tour of a new garlic curing and storage facility along with a cultivar trial. Updates on tank mix policies, Canada GAP, mechanization, weed control, Fusarium management as well as updates about the clean seed program will be discussed. Register by going to https://www.garlicgrowersofontario.com/.
Onions – Earliest direct seeded onions are at the first true leaf stage while the majority of fields are in the loop/flag leaf stage. Cool nights have made germination rates variable in some drier fields. Transplant fields are establishing well with some older leaves showing tip dieback and yellowing in areas where night temperatures were low. Onion and seedcorn maggot flies have reached their threshold for the first-generation emergence in all counties except for Sudbury, Timiskaming and Thunder Bay. Keep on the lookout for wilted plants and dig suspect plants to inspect roots for maggot larvae.
Tomatoes – planting is about 65% complete 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
|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|
*NOTE: Data as of May 24th, 2023
*- 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: