VCR – Vegetable Crop Report – May 15th, 2025

Welcome back to the next VCR of 2025!

Excluding the northern counties of Sudbury, Thunder Bay, and Timiskaming, all counties are currently trending above their 10 year average GDD. Almost all counties, excluding Essex, have also had a relatively dry May so far.

Crop Updates

Brassica – Transplanting continues across the province. We are still a way away from seeing the first-generation threshold for cabbage maggot in most counties. Currently 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. 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. An Emergency Use Registration for Cimegra has been approved for broccoli, Brussels sprouts, cabbage, and cauliflower against cabbage maggot for the 2025 field season. Dig up wilted plants and inspect the roots for wireworm, seedcorn maggot larvae feeding or millipede damage. If you were unable to attend the Brassica IPM scouting workshop, a recorded version can be found at: https://www.youtube.com/watch?v=pjHoSwQej-k

Carrots – If you missed the Carrot and Onion IPM training, you can access it here to refresh your memory on carrot disease and insect pests: https://youtu.be/moY8MPmzy88

Garlic – Plants have really grown in the last week. Many fields have reached 10 leaves per plant and will be sending out a scapes soon. Consider irrigating in areas that have been dry. The number of leek moth catches has gone down in most areas over the past week but be on the lookout for feeding damage from the newly hatched larvae. The Garlic Growers Association of Ontario is hosting the 2025 field day Saturday, June 7th at Felix Furmanek Farms near Arthur, Ontario. Equipment from multiple manufacturers will be on display, along with products from fertilizer and pest control product suppliers. The agenda includes presentations on results from past trials, a tour of a new garlic curing and storage facility along with a field tour of cultivar / clean seed demonstration trials Registration starts at 9:00, the agenda starts at 9:30 and goes until 4:30. Lunch will be provided. Felix Fumanek Farms is located at 8818 Wellington County Rd 14, Arthur, Ontario, and all are welcome to join, rain or shine. Please register for the field day by going to https://www.garlicgrowersofontario.com/field-day-2025.

Onion –With the threshold for the first generation of onion maggot reached in many locations over the past two weeks, eggs are hatching out and larvae damage will result in wilting plants. 2023 was the last year to use Lorsban / chlorpyrifos products for maggot management. Transplants are at the greatest risk since no products are registered as a transplant drench, and seed treated with Sepresto 75 WS will have likely worn off by the time the onion is transplanted. Releasing sterile onion maggot flies has shown to successfully manage onion maggot in 2500 acres of onions in Quebec and nearly 100 acres of onions in Ontario. More information about this technology can be found in this past ONvegetables article: https://onvegetables.com/2025/01/27/sfr-2/. If you were unable to attend the Onion IPM scouting workshop, a recorded version can be found at: https://www.youtube.com/watch?v=moY8MPmzy88

Potatoes – The Ontario Potato Soft Rot and Blackleg survey is continuing for 2025. If you are having seed or emergence issues this spring, you can get it tested for free through this project.

More details can be found here: Potato Bacterial Soft Rot Survey – ONvegetables

Remember to sign up for the Ontario Potato Scout Training on Wednesday May 28^th: 2025 Ontario Potato Scout Training – ONvegetables

Good planting conditions over the last 2 weeks have continued and more than half of the potato acres have now been planted. Soil temperatures remain lower than average so monitor for seed and emergence issues.

Tomatoes – Planting has just begun. Nighttime temperatures are still quite cool. Growers should look for chilling injury if air temperatures drop below 10°C. Also, scouting for early season insect pests, such as Colorado potato beetle and black cutworm, should be started as soon as transplanting is complete. If growers are concerned about wireworm in the field, treatment needs to be made to transplants before planting.

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***	232	192	98	59	20	124	192	44
Chatham-Kent*	354	301	167	110	46	204	301	87
Durham***	277	234	132	80	30	163	234	61
Essex*	414	358	214	143	65	257	358	115
Huron***	297	251	145	95	43	175	251	75
Kemptville***	278	236	132	82	36	163	236	64
Lambton**	338	286	161	105	44	198	286	83
Middlesex**	323	275	154	97	35	190	275	74
Norfolk**	340	290	161	101	40	199	290	77
Peterborough	259	217	113	70	28	143	217	54
Renfrew	257	218	118	72	33	148	218	55
Simcoe***	253	210	112	66	23	140	210	48
Sudbury***	134	112	59	39	21	73	112	33
Thunder Bay	100	79	37	22	7	46	79	16
Timiskaming***	116	94	48	32	16	59	94	25
Wellington Centre**	268	225	121	72	24	153	225	52
Wellington North**	274	232	127	81	32	158	232	62