VCR – Vegetable Crop Report – May 1, 2020

Map of Ontario with Growing Degree Days as of April, 29th, 2020

The Vegetable Crop Report is back for another season! We hope everyone is staying safe, and your field season’s are off to a good start despite everything that is going on.

Temperature – Growing Degree Day values are lagging behind 10-year averages across all growing regions in the province due to the cooler temperatures we’ve experienced so far this year. Warmer temperatures expected to arrive in this upcoming week should help bring all regions closer to their respective averages. Temperatures have not yet been warm enough to trigger pest forecasting thresholds for any regions (a possible exception being leek moth emergence in some southern portions of the province). Degree day data for each region is shown below.

Rainfall – Most regions received above average rainfall in March but well below their respective average rainfall totals for April this year. Simcoe and Peterborough being the exceptions which received below average rainfall in both March and April. Precipitation data for each region is shown below.

Crop Updates

Asparagus – Cooler weather has kept emergence slow.

Brassica Crops – A portion of head brassica acreage has been transplanted over the last week in warmer areas of the province and dryer areas have required irrigation after transplanting. Register now for the online Brassica IPM Scouting Workshop next Thursday, May 7^th. The main focus will be on identifying the differences between different insect pests and pathogens of Brassica crops.

Celery – Register now to attend the online Carrot and Celery IPM Scouting Workshop scheduled for next Tuesday, May 12^th.

Cucurbit Crops – The earliest planting date for the warmest area of Ontario tends to be around May 10, Register now for the online Cucurbit IPM Scouting workshop for Thursday, May 20^th.

Garlic – The emergence rate across the province has been high. Warmer weather in March caused plants to jump ahead in growth and colder periods in April, including several hard frosts, has caused some plants to show tip burn on older leaves. If the plan is to add more fertilizer this season, the sooner the better. Plants in many areas have reached the 5^th leaf stage and the amount of nitrogen in applications should be reduced to avoid rough bulbs at harvest. Now is the time to set up leek moth traps as adult moths emerge from overwintering sites and are looking for a place to lay eggs once the night temperature remain above 9.5°C for two consecutive nights. If your garlic already shows leaf damage due to an insect, please send photos to travis.cranmer@ontario.ca.

Onions – It has been cool and dry up until recently making direct seeded onions slow to germinate and transplants slow to establish. Once the flag leaf has emerged, count out 25 plants per row and put a stake or stick at each end and record the number of plants every few days. Count the number of plants over the next few weeks and monitor for damage due to maggot flies, damping-off or cold weather. Register now for the online Onion IPM Scouting workshop for Thursday, May 14^th. Onion insect and pathogen scouting will be the focus of the webinar.

Rhubarb – Some frost damage has been observed on emerging leaves. Remove wilted stalks and monitor for secondary infection.

Sweet Corn, Beans and Peas – Planting is underway. Register now for the online Sweet Corn, Beans and Peas IPM Scouting workshop for Friday, May 15^th.

NOTE: Data as of April 29th, 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*	169	129	48	24	6	68	129	17
Chatham-Kent*	137	101	37	20	4	51	101	14
Norfolk**	146	111	37	18	4	54	111	12
Huron***	101	76	31	17	4	41	76	11
Wellington**	87	59	16	7	1	24	59	4
Simcoe County***	86	59	18	9	3	28	59	6
Durham***	105	77	22	9	2	33	77	6
Peterborough	92	65	21	9	3	30	65	6
Kemptville***	88	64	21	11	6	29	64	8
Sudbury***	24	14	2	0	0	4	14	0