Temperature – Degree day accumulation slowed this week across most of the growing regions as cooler weather arrived. Continue to be vigilant in scouting for pathogens as crops approach harvest as cooler weather combined with heavy dew and precipitation may be conducive for the development of plant pathogens. Chatham and Essex, have held steady with their average degree day accumulation while Kemptville, Norfolk and Wellington have fallen back below their average degree day accumulations along with the other growing regions.
Rainfall – All growing regions received rainfall in the past week with varying amounts based on location. Essex has already received two thirds of its average rainfall and is well on its way to exceeding its September average. Remaining growing regions have received about half or below their monthly averages. Remember to try and avoid scouting or equipment through fields when they are still wet. This will help to avoid the spread of some plant pathogens, especially in fields which are still a few weeks away from harvest.
Brassica Crops – Diamondback moths and flea beetles continue to be problems in multiple areas. Scout for Alternaria, downy mildew and look for stunted plants. A clubroot pathotype study is underway; if you have Brassicas with clubroot and are interested in determining what pathotype of clubroot is present, E-mail firstname.lastname@example.org for more information.
Fig 1. Clubroot causing stunting in cauliflower.
Celery – Celery harvest continues. For late plantings, continue to scout for bacterial blight, pink rot and celery leaf curl. Avoid scouting when leaves are wet as pathogens can spread easily on clothes and equipment throughout the field.
Garlic – Planting season is underway. Check planting stock for bulb and stem nematode before planting. Even cloves with an intact basal plate and no observable damage may have nematodes present. There will be another full day workshop in Guelph on December 4th that will cover every part of garlic production including clean seed, cultivar selection, seeding density, nutrient testing, scape removal, weed control, crop insurance, harvesting, grading, storing as well as scouting/pest management. To register, call the Agriculture Information Contact Centre at 1 877-424-1300.
Onions – Onion harvest is underway. Downy mildew was confirmed in Ontario transplant onions two weeks ago; but no infections have been seen in the major onion growing regions. The level of Stemphylium leaf blight development seemed to be less than last year and the level of thrips this year was low in most areas. The level of pink root and onion smut seemed to be higher this year but overall yield and quality seems to be good across the province.
Pest Degree Day Forecasting
|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: