VCR – Vegetable Crop Report – June 5th, 2025

Welcome back to the next VCR of 2025!

Currently, many counties are trending at or slightly below their 10 year average GDD.

Crop Updates

Brassica Crops – Transplants are starting to take off in fields that were planted in late April or early May. Cabbage maggot has reached its first-generation threshold in Southern regions and maggot activity has been found in several fields. Dig up wilted transplants, even in dry areas, to inspect roots for maggots. For cabbage maggot management, Success (Group 5) and Verimark (Group 28) are registered as greenhouse tray drenches and Verimark can also be used as an in-furrow application in the transplant water at the time of transplanting. Scorpio Ant and Insect Bait has recently been registered as a broadcast application focused at the base of the plant after transplanting. An Emergency Use Registration for Cimegra (Group 30) has been approved for broccoli, Brussels sprouts, cabbage, and cauliflower against cabbage maggot for the 2025 field season, which is also a product for use at time of transplanting. Flea beetles and cutworms are active. Products registered for cutworm management are most effective when they are applied early when the cutworm larvae are small. This week, keep a look out for diamondback moths and imported cabbageworms this week.

Garlic – Be on the lookout for leek moth damage as hardneck cultivars are scaped over the next two weeks. Refer to this article for managing leek moth: https://onvegetables.com/2025/03/07/leekmoth-3/. Snap scapes of hardneck cultivars as soon as possible to obtain the greatest yield benefit. Avoid using sickle bar mowers or any knife to remove scapes as they can easily spread garlic pathogens (including viruses) and often damage leaves during the scape removal process. Past research has shown that by accidentally removing one leaf when the scape was removed, bulb sizes were reduced by 13% and the yield was reduced by an average of 17.5%. The same trial showed that yield was greatly impacted as the number of leaves cut during mowing increased. If the top two leaves were cut, the yield was reduced by approximately 25%, almost outweighing any potential gains you would expect by removing the scape in the first place. Register for this years Garlic Growers Field Day on June 7th. Go to https://www.garlicgrowersofontario.com/field-day-2025 to register.

Onion – Direct seeded fields are between the flag and 4th leaf stage. Transplants are doing even better in fields where they have had enough moisture to establish. Onion maggots are active. Be on the lookout for wilted plants. Stake/count 50 or 100 plants now and count later in the seasons to determine how many onions make it to harvest. While scouting, continue to be on the lookout for cutworms.

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***	417	356	200	125	52	246	356	97
Chatham-Kent*	594	519	319	218	105	378	519	174
Durham***	488	424	260	167	74	311	424	130
Essex*	655	578	371	259	126	435	578	210
Huron***	474	407	243	162	81	291	407	132
Kemptville***	508	446	278	188	98	330	446	154
Lambton**	563	488	298	201	102	356	488	163
Middlesex**	571	500	309	206	99	368	500	165
Norfolk**	540	468	277	179	84	335	468	140
Peterborough	466	402	235	151	66	285	402	118
Renfrew	487	427	264	180	95	315	427	146
Simcoe***	458	394	235	151	74	283	394	121
Sudbury***	328	283	166	113	58	201	283	93
Thunder Bay	257	217	120	71	22	147	217	51
Timiskaming***	306	263	160	110	55	190	263	89
Wellington Centre**	458	394	228	143	62	280	394	112
Wellington North**	463	401	233	157	75	284	401	127