VCR – Vegetable Crop Report – May 26th, 2022

Temperature – All counties are meeting or surpassing their 10 year GDD averages. Temperatures are expected to rise into the mid- to high- twenties at the beginning of next week before dropping again slightly towards the end of the week.

Precipitation – All counties saw some rainfall over the past week though most are behind the 10 year average. Kemptville however has now greatly surpassed their 10 year average rainfall for May. Rain is forecasted for tomorrow in most regions except Sudbury which may see rainfall later. There is also the risk of thunderstorms in some areas.

Crop Updates

Brassica Crops – Flea beetles, swede midge and cutworms are active. Seedcorn maggot has reached the threshold for first generation emergence and cabbage maggot will be emerging soon in most regions across the province and is likely already active in Essex and Chatham-Kent. Diamondback moths and imported cabbageworms are likely to be observed very soon. Pull up wilted plants and inspect roots for larvae.

Celery – Transplants are establishing well, and most fields have been planted across Southwestern Ontario. The threshold for aster leafhopper has been reached in Essex, Chatham-Kent, Norfolk, Huron and Kemptville, Sudbury and every county has had enough growing degree days for tarnished plant bug.

Garlic – Plants showing tipburn earlier in the season are starting to look better as the newer leaves emerge. Scout for leek moth by looking for green frass and ragged leaves. Insecticides should be applied ~7 days after peak trap capture. Wireworm, cutworm and seedcorn maggot damage has been observed.

Onions – Earliest direct seeded onions are at the third leaf stage while the majority of fields are in the flag or 1st leaf stage. The cool weather has made germination rates variable in many fields. Transplant fields are establishing well. Onion and seedcorn maggot flies have reached their threshold for the first-generation emergence in all counties except for Sudbury and damage from early season activity has been observed. Dig up wilted plants and inspect roots for onion maggot larvae.

Tomatoes – planting is about 75-80% 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

*NOTE: Data as of May 25, 2022

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
Essex*	488	427	265	185	102	314	427	153
Chatham-Kent*	426	369	223	153	76	268	369	126
Norfolk**	427	372	229	154	73	274	372	124
Huron***	385	334	202	137	68	241	334	111
Wellington**	356	307	177	114	54	217	307	93
Simcoe County***	351	301	175	110	53	213	301	88
Durham***	389	335	197	128	55	239	335	100
Peterborough	345	296	167	106	40	206	296	81
Kemptville***	398	341	205	141	67	243	341	114
Sudbury***	258	226	139	95	50	166	226	79