Welcome to the second week of the VCR Report for the summer! Fields have started to dry out and planting is underway across the province.
Brassica crops – Cabbage maggot is likely active in Essex county and nearing its first-generation threshold in several other counties. Seedcorn maggot fly is likely active in Essex, Chatham-Kent and Lambton counties. Dig up wilted transplants and inspect roots for insect damage. 2023 is the last year to use Lorsban / chlorpyrifos products for maggot management. Success (Group 5) and Verimark (Group 28) are registered as greenhouse tray drenches and Verimark can also be used as an in-furrow application in the transplant water at the time of transplanting. Be on the lookout for flea beetle emergence as the soil temperature reaches above 10°C. If you were unable to attend the 2022 Brassica Crops IPM Scout Training workshop, a recorded version can be viewed below: https://www.youtube.com/watch?v=fHf0y1xG0kI
Garlic – Plants are at an average of 4-8 leaves. Cool weather as well as herbicide applications, have caused leaf yellowing in many fields. The nightly lows have not been above the 9.5°C required for leek moth in most regions, however, leek moth has been detected and is likely active across the province in sheltered areas that experienced warmer night temperatures. Seedcorn maggot fly damage has been observed in SW Ontario and has reached its first-generation threshold in Essex, Chatham-Kent and Lambton counties. Dig up plants that have wilted leaves to look for seedcorn maggot larvae, wireworms or millipedes as described in last week’s VCR.
Onion – Transplanting is underway across the province and many fields have been direct seeded in drier areas. The threshold for seedcorn and onion maggot fly have been reached in Essex, Chatham-Kent and Lambton counties. If you were unable to attend the Onion IPM scouting workshop, a recorded version can be found at: https://www.youtube.com/watch?v=OwGISdtuNEU
Carrots – We have not reached the Degree Day threshold for any carrot insect pests to emerge. With a warm weekend we should reach emergence of carrot weevil in the SW regions of the province.
Potatoes – Be mindful of applying herbicides in cool, wet soil conditions as efficacy is generally decreased and potential for crop injury is increased.
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 8th, 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: