Temperature – Many regions are at or below the 10-year average accumulated degree day average so far this year. Sudbury has had just over half the growing degree days compared to its 10-year average while Huron, Wellington, and Simcoe County are marginally ahead. While some regions are now receiving average temperatures resulting in average growing degree days, the lack of sun has likely slowed the growth of many crops in most planted areas.
Rainfall – Most regions have had above average rainfall in March and April and many are on track to also exceed the average rainfall in May. Precipitation levels shown in the charts below for 2019 show the precipitation up to May 22nd compared to the total monthly average of the previous 10 years. The recent pause in rainfall this week has allowed some growers entry into the field to begin planting, however seeding is still delayed in many regions.
Brassica Crops – Cool night temperatures have resulted in some plantings with tip dieback. The degree day threshold for cabbage maggot emergence has not been reached in all areas of the province.
Carrots – We are just getting into the bulk of seeding this week. Carrots are not too far behind schedule but some early carrots fields went in a little later than usual. Carrot fields that have emerged look great.
Celery – Transplanting is underway in many areas and insect pressure is low.
Garlic – Overwintering leek moth adults have been detected in traps across Southwestern Ontario. Use pheromone traps to monitor populations on a weekly basis to accurately time management strategies. Dig up any wilted plants you find and check for maggots, lack of basal plate or feeding damage.
Onions – The last week has allowed many acres of direct seeded onions and transplants to be planted. Early seeded onions are at the loop to flag leaf stage. Agricorp extended the direct seeded onion planting date onion to yesterday, May 22nd, and the Spanish onion planting date of May 20th is extended to May 27th. The first generation of onion and seedcorn maggot flies are active in Essex, Chatham-Kent and Norfolk. Check for insect pressure by digging up wilted/stunted plants and scout for maggots or feeding damage.
Potatoes – Potato planting is behind schedule due to the precipitation, but is now ramping up in most regions. Be wary of emergence issues and seed rots when planting into cold and wet ground. If you’re using cut seed, allow it to suberize/heal before planting, especially if you’re also using a liquid seed treatment.
Tomatoes – Tomato planting started on May 15th and only about 20% of the crop is in the ground, compared to 60% seen in past years. For those that have planted, moist soil conditions are ideal for black cutworm and wireworm. Growers should keep an eye out for damaged transplants, especially along field edges and in areas were there was significant weed cover before tillage.
Pest Degree Day Forecasting
Select a region below for the latest weather, crop and pest degree day information:
|Pest||Carrot Rust Fly||Onion Maggot||Carrot Weevil||Aster Leafhopper||Tarnished Plant Bug||Cabbage Maggot||Seedcorn Maggot|
Use these thresholds as a guide, always confirm insect activity with actual field scouting and trap counts.