VCR – Vegetable Crop Report – August 8th, 2025

Welcome back to the next VCR of 2025!

Currently most counties are trending at or slightly above their 10 year average GDD, with Sudbury and Timiskaming county trending slightly below their 10 year average.

Crop Updates

Brassica Crops – In fields with overhead irrigation, conditions have been favourable for Alternaria development and Brassica downy mildew. Switch 62.5 WG (Groups 9/12) was registered last year for use on head Brassica’s for suppression against Alternaria leaf spot. After blocks are harvested, be sure to incorporate all crop residue in the soil to reduce the amount of surviving of larvae and inoculum available to infest and infect later plantings. With the heat and lack of moisture, nutrient disorders have been common with head brassicas including sun scald, edema and splitting.

Garlic – Most garlic has been cured and is going into storage. Once cured, table stock can be kept at a temperature of 0.5°C at a relative humidity of 55-65% and planting stock can be kept above 14°C (up to 18°C) at a relative humidity of 55-65%. Avoid a relative humidity above 70% or a temperature above 3°C as this can promote sprouting in storage. Low levels of nematodes can be found in planting stock that otherwise looks great. Here’s an article summarizing the things to consider before purchasing new garlic planting stock: https://onvegetables.com/2022/08/05/garlicplanting/

Onions – Transplants are being harvested and some direct seeded fields are starting to lodge. Stemphylium leaf blight is slowly causing tip dieback, but it is not as severe relative to previous years for mid-August. As fields of transplants are harvested, be mindful of younger, direct-seeded onions in border fields as the level of thrips may surge as they move to a greener crop, especially in this hot and dry weather.

Pest Degree Day Forecasting

County	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
Bruce***	1440	1315	967	764	500	1077	1315	672
Chatham-Kent*	1786	1647	1255	1026	721	1378	1647	918
Durham***	1655	1527	1170	950	664	1286	1527	848
Essex*	1902	1761	1362	1122	797	1490	1761	1009
Huron***	1577	1445	1085	875	600	1199	1445	780
Kemptville***	1647	1520	1161	942	661	1277	1520	844
Lambton**	1730	1591	1209	984	692	1331	1591	882
Middlesex**	1755	1619	1237	1006	706	1359	1619	900
Norfolk**	1687	1552	1168	942	653	1291	1552	839
Peterborough	1562	1434	1075	863	586	1190	1434	766
Renfrew	1642	1518	1164	951	675	1278	1518	854
Simcoe***	1578	1450	1099	887	618	1211	1450	793
Sudbury***	1310	1201	893	711	466	991	1201	627
Thunder Bay	1159	1056	766	589	356	857	1056	507
Timiskaming***	1247	1140	845	669	429	938	1140	586
Wellington Centre**	1551	1423	1065	852	579	1180	1423	756
Wellington North**	1554	1427	1068	864	590	1183	1427	770