VCR – Vegetable Crop Report – May 28, 2020

Temperature – High temperatures this past week have helped Growing Degree Day values catch up to around the 10-year average in most regions. Peterborough and Kemptville remain marginally behind. Temperatures are expected to cool over the next week across Ontario. Carrot Rust fly thresholds have been triggered in Chatham-Kent and Norfolk counties, while Essex County is past the first threshold range. Many regions have reached the first carrot weevil threshold with some having already surpassed the first generation values. Onion and seedcorn maggot thresholds have been triggered in all regions except Sudbury. Aster Leafhooper thresholds have been reached in Essex, Chatham-Kent and, Norfolk counties. Degree day data for each region is shown below.

Rainfall – All regions continue to lag behind 10-year average values. There is a chance of some rain across Ontario in the next week but Sudbury could see showers throughout. Precipitation data for each region is shown below.

Crop Updates

Asparagus – Harvest is underway, these are peak weeks for spear production. Scout for Phytophthora symptoms which may be confused with frost damage from last week, and be on the lookout for Asparagus Beetle and Cutworms.

Beans & Peas – Peas have reached the 2-3 node stage, some peas saw minor frost damage last week. Some peas have begun flowering in some areas.

Brassica Crops – Most transplants are bouncing back from the frost and are putting up new leaves. Flea beetles are active and being observed in high numbers in Southwestern Ontario. Seedcorn maggot has reached the threshold for first generation emergence.

Celery – Celery transplants are establishing well. The threshold for aster leafhopper has been reached in Essex county while nearly every county has had enough growing degree days for tarnished plant bug.

celery_may26 — Celery transplants are establishing well – May 26, 2020

Cucurbits – cucumber beetle came out of dormancy in large numbers this week and has been found on squash and watermelon: prioritize scouting of summer squash and any propagated or planted pumpkin as these are highly attractive to these beetles.

Garlic – Leek moth is active in all growing regions that it has observed in moderate levels in the past. If counts are lower next week compared to this week, the bulk of the emerged larvae will be targeted if an insecticide is applied 7 – 10 days after peak trap capture. Garlic is showing tipburn across all regions of the province.

Onions – Earliest direct seeded onions are at the third leaf stage while the majority of fields are in the 1st leaf stage. Transplant fields are overcoming frost damage from the middle of May. Onion and seedcorn maggot flies have reached their threshold for the first generation emergence in all counties except for Sudbury.

onion_may26 — Transplant onion with tip dieback from frost – May 26^th, 2020

Sweet Corn – Early planted sweet corn saw some frost damage last week.

NOTE: Data as of May 27th, 2020

Pest Degree Day Forecasting

Pest	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*	438	371	216	150	81	260	371	125
Chatham-Kent*	384	323	194	138	69	229	323	115
Norfolk**	388	328	186	131	65	225	328	108
Huron***	307	263	165	117	56	192	263	95
Wellington**	296	246	144	101	50	172	246	82
Simcoe County***	294	247	149	106	57	177	247	88
Durham***	322	270	156	110	55	185	270	91
Peterborough	304	252	146	100	49	174	252	81
Kemptville***	312	263	152	107	56	179	263	89
Sudbury***	222	192	127	98	58	144	192	85