VCR – Vegetable Crop Report – September 12, 2019

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.

Crop Updates

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 travis.cranmer@ontario.ca for more information.

Clubroot_cauliflower 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
Essex*	2417	2245	1759	1461	1054	1917	2245	1317
Chatham-Kent*	2205	2035	1562	1269	832	1715	2035	1133
Norfolk**	2118	1954	1492	1207	774	1642	1954	1074
Wellington**	1865	1712	1275	1011	616	1415	1712	889
Simcoe County***	1885	1729	1293	1029	637	1432	1729	907
Durham***	1988	1832	1396	1134	729	1535	1832	1009
Peterborough	1799	1643	1202	933	545	1344	1643	811
Kemptville***	2018	1861	1420	1145	729	1562	1861	1011
Sudbury***	1660	1519	1122	882	518	1248	1519	770