Temperature – Day temperatures are forecasted to be mid-high teens all the way to the high twenties depending on the region.
Nighttime temperatures are forecasted to be in the low teens for most regions. The Growing Degree Day values continue to increase well above their 10-year average values in most regions. Degree Day data for each region is shown below.
Rainfall – A majority of regions are well behind the 10-year average for rainfall in the month of May. There are chances of rain and thunderstorms for the remainder of this week and into the weekend in many regions. Precipitation data for each region is shown below.
Brassica Crops – Most transplants are showing frost damage across the province with the outer most leaves turning purple or yellow. While it has not been warm enough for cabbage maggot fly to reach it’s first generation growing degree threshold in any county, seedcorn maggotfly is active in most regions. If you were unable to attend the Brassica Crops IPM scouting workshop, a recorded version can be found at:
Carrot – Early seeded carrots have survived some early frost events and are growing well. As we are now into the bulk of carrot seeding, conditions are fairly dry. Irrigation may be required to ensure even germination and emergence as well as to activate any pre-emergence herbicides. If you were unable to attend our carrot IPM scout training last week here is a YouTube video link for you to catch up on or refresh your memory:
Garlic – Most crops across the province overwintered well and there were little problems with emergence. With the warm weather in March and April, many fields are much more advanced than this time last year. Hard frosts in April when plants were past the 5 leaf stage caused yellowing of older leaves and in many regions plants are showing some sort of tipburn. Most plants are past the 5th leaf stage, so avoid applying nitrogen to reduce the amount of rough bulbs at harvest as well as to encourage longer storage life. The nightly lows have not been above the 9.5C 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. If any wilted plants are found, dig up plants with a trowel and inspect roots for maggot fly larvae or wireworms. If your garlic already shows signs of leaf damage due to an insect, please send photos to firstname.lastname@example.org.
Onions – The cool, dry weather has made it difficult for some seeded fields to germinate evenly and transplants have been slow to establish. Once seeded onions have emerged, count out 25 plants per row and put a marker at each end and record the number of plants every week. These damage plots will be valuable to monitor the amount of damage due to maggot flies or other pests. The threshold for seedcorn and onion maggot fly have been reached in all counties below except for Sudbury. If you were unable to attend the Onion IPM scouting workshop, a recorded version can be found at:
Potatoes – Early planted potatoes are emerging and growing well with this warm weather. The bulk of potatoes are currently being planted.
Tomatoes – Planting is underway. Scouting for early season pests should be started as soon as transplanting is complete. Be sure to scout for early season insect pests such as cutworms, wireworms (pictured below) and Colorado potato beetle. If you were unable to attend the Tomato and Pepper IPM scouting workshop, a recorded version can be found at:
Pest Degree Day Forecasting
*NOTE: Data as of May 17th, 2021
|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: