Frost stress reported across Ontario vegetable crops after May cold snap
May 19, 2020 By OMAFRA Vegetable Team
Frost stress among various vegetable crops was reported in many regions after a burst of cool May weather, according to Ontario’s latest May 14 vegetable crop report. The vegetable crop report is published by Ontario’s Ministry of Agriculture, Food, and Rural Affairs (OMAFRA)’s vegetable team.
The second and third week of May saw temperatures dip below zero in many regions. According to OMAFRA’s vegetable crop report, frost stress was reported in many regions that had started planting.
In brassica crops across the province, most transplants showed frost damage with the outer most leaves turning yellow. Early planted carrots and onions struggled throughout frost events. The vegetable team noted that cold nights have made it difficult for onion transplants to establish, but despite cooler weather seeded onions are at the loop stage in many regions.
The vegetable team noted that cold nights have made it difficult for onion transplants to establish, but despite cooler weather seeded onions are at the loop stage in many regions.
The vegetable team noted frost damage for emerged potatoes, rhubarb, garlic, and emerged asparagus. However, the vegetable team also noted many crops were still spared. Cooler temperatures have kept asparagus emergence slow and many potato acres have been recently planted so seed pieces remained safe from any frost layer.
Warmer temperatures are expected in the upcoming weeks across Ontario and this may help growing degree day values catch up to their averages.
Growing degree day values in Ontario lag far behind the 10-year average in all regions. The cooler weather follows the same patterns seen in OMAFRA’s previous crop report which also noted below-average growing degree day values. Many regions continued to have little accumulation in the past week.
Growing degree day values in Ontario lag far behind the 10-year average in all regions.
Temperatures have still not yet been warm enough to trigger pest forecasting thresholds for any regions. The vegetable team explained that a possible exception is leek moth emergence in some southern portions of the province.
While all regions are significantly behind the half way mark for their 10-year averages, rainfall is forecasted for all regions over the course of the next week. Thunderstorm warnings have already sprung up for the southern portion of the province in Essex, Chatham-Kent, and Norfolk counties.
OMAFRA scouting workshops for growers
Included in the vegetable update was a list of online scouting workshop the vegetable team will be hosting through the month of May. Click the links for more information:
- May 6, 2020 – Tomatoes and Peppers IPM Workshop
- May 7, 2020 – Brassica IPM Scouting Workshop
- May 12, 2020 – Carrot and Celery IPM Scouting Workshop
- May 14, 2020 – Onion IPM Scouting Workshop
- May 15, 2020 – Sweet Corn, Beans and Peas IPM Scouting Workshop
- May 20, 2020 – Cucurbit IPM Scouting Workshop
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