VCR – Vegetable Crop Report – July 31st, 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 – Nutrient disorders have been a common problem in head brassicas, from tip dieback on leaves to uneven head development to leaf edema. Not only is wilt caused by extreme temperatures, wilt can also be caused by cabbage maggots, wireworms, clubroot and other pests/pathogens that are targeting the roots. It is a good idea to dig up wilted plants with a shovel and examine roots to see if any pests are present or if the wilt is caused from the heat. Conditions have been favourable for Xanthomonas or black rot of Brassicas. Populations of thrips are increasing and could become problematic in cabbage.

Garlic – Harvest has mostly finished. As garlic cures, check bulbs in the middle of pallet boxes or totes regularly to get a good sense of how the entire crop is drying outMonitor humidity levels while you are curing the harvested crop. Curing / drying is often associated with an increase in temperature, however, when it comes to curing garlic, relative humidity should be the primary focus. Keeping the relative humidity low and curing the crop quickly has shown to be the best way to avoid garlic mites, fusarium development, and improve storage longevity. Good air circulation through totes, pallet boxes or baskets that reach all bulbs evenly will help to reduce over-curing some bulbs or under-curing others. . Aim to remove ~ 20% of the total weight at harvest in order to properly cure the bulbs. Curing is complete when the bulb wrappers are crispy, the middle of the cut stem is hard, and the base of the stem is dry when cloves are removed. In the field, incorporate debris left after harvest to reduce the likelihood of leek moth completing its lifecycle.

Onions – Transplants are close to being harvested. Scout for wilted plants as the second wave of onion maggots are active in most onion growing regions. Some areas may be at a high risk for onion downy mildew given the high humidity, heavy dews and colder mornings. While there are many products registered for onion downy mildew, past work by the Ontario Crops Research Centre – Bradford has shown that Orondis Ultra (groups 40/49), Zampro (groups 45/40) and Ridomil Gold Mz (groups 4/M3) are effective. Stemphylium is starting to infect and cause tip dieback in many fields, especially those where the older leaves are senescing early due to moisture stress.

Potatoes – Late blight continues to be found in New York State. With overnight temperatures cooling and lush canopies starting to collapse, the risk of late blight remains high.

We are continuing the blackleg and soft rot survey from last season and have room for some more submissions. If you are seeing wilting plants and blackleg symptoms, please contact Dennis and we can come pick up samples.

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***	1315	1198	875	688	448	976	1198	604
Chatham-Kent*	1651	1520	1152	939	658	1267	1520	839
Durham***	1510	1390	1057	853	591	1165	1390	759
Essex*	1763	1630	1255	1031	730	1375	1630	926
Huron***	1448	1324	989	794	543	1094	1324	707
Kemptville***	1518	1399	1064	861	604	1172	1399	771
Lambton**	1593	1463	1104	896	627	1219	1463	801
Middlesex**	1617	1489	1131	916	640	1245	1489	818
Norfolk**	1559	1431	1072	862	597	1186	1431	767
Peterborough	1416	1298	966	771	522	1071	1298	683
Renfrew	1487	1372	1045	850	601	1150	1372	762
Simcoe***	1443	1323	996	801	555	1100	1323	714
Sudbury***	1171	1071	790	625	407	879	1071	550
Thunder Bay	1034	938	673	512	303	756	938	438
Timiskaming***	1131	1032	761	602	386	847	1032	527
Wellington Centre**	1420	1300	966	769	520	1074	1300	682
Wellington North**	1427	1308	972	784	534	1079	1308	698