VCR – Vegetable Crop Report – May 25th, 2023

Welcome back to the next VCR Report for 2023! With only a few days of May remaining, many counties are behind in their monthly totals for precipitation compared to their ten year average. Most counties are close to their ten year average when it comes to degree days with a base of 5°C.

Brassica Crops – Many areas received temperatures at or below -4°C last week which has resulted in tip dieback of some older leaves. The degree day threshold for cabbage maggot emergence has yet to be reached in any county, while seedcorn maggot is active across most of the province. Observe the roots of wilted transplants and look for wireworms or cutworm larvae. Check stunted plants for wirestem and scout for flea beetles, diamondback moths, imported cabbageworms and cutworms.

Garlic – Plants showing tip burn earlier in the season are starting to look better as more new leaves emerge. Scout for leek moth by looking for green frass and damaged interior leaves. Insecticides should be applied ~7 days after peak trap capture. The Garlic Growers Association of Ontario is hosting their annual field day June 10^th. Equipment from multiple suppliers will be on display, along with products from fertilizer and pest control product suppliers. The agenda includes a tour of a new garlic curing and storage facility along with a cultivar trial. Updates on tank mix policies, Canada GAP, mechanization, weed control, Fusarium management as well as updates about the clean seed program will be discussed. Register by going to https://www.garlicgrowersofontario.com/.

Onions – Earliest direct seeded onions are at the first true leaf stage while the majority of fields are in the loop/flag leaf stage. Cool nights have made germination rates variable in some drier fields. Transplant fields are establishing well with some older leaves showing tip dieback and yellowing in areas where night temperatures were low. Onion and seedcorn maggot flies have reached their threshold for the first-generation emergence in all counties except for Sudbury, Timiskaming and Thunder Bay. Keep on the lookout for wilted plants and dig suspect plants to inspect roots for maggot larvae.

Tomatoes – planting is about 65% complete for processing tomatoes and fresh market tomatoes are continuing with their staggered planting schedules. Be sure to keep and eye out for early season insect pests like black cutworm, wireworm and Colorado potato beetle. These pests are becoming more of an issue with the loss of some key insecticides and early detection is key to managing them effectively

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***	274	232	128	73	30	160	232	56
Essex*	463	401	248	175	88	292	401	145
Chatham-Kent*	423	363	222	154	75	264	363	126
Norfolk**	393	335	202	135	60	240	335	107
Huron***	340	289	175	115	51	208	289	89
Wellington**	319	274	165	108	50	198	274	85
Simcoe County***	329	282	167	112	55	201	282	90
Durham***	355	303	176	117	50	211	303	91
Peterborough	336	288	163	104	43	200	288	81
Kemptville***	361	313	190	123	51	228	313	94
Sudbury***	240	204	114	65	21	141	204	45
Timiskaming***	229	193	97	50	13	127	193	32
Lambton**	403	348	211	147	73	252	348	119
Thunder Bay	164	133	60	32	9	82	133	22
Middlesex*	387	333	207	142	69	243	333	116
Renfrew	347	302	181	116	46	219	302	90