VCR – Vegetable Crop Report – May 4th, 2023

The Vegetable Crop Report is back for another season! Most regions have experienced a wet April compared to their 10-year average.

Brassica Crops – A portion of head brassica acreage has been transplanted over the last week in warmer areas of the province in fields that were well drained.

Carrots – Early seeded carrot fields have now been sitting in cool and wet soil conditions so keep an eye out for Pythium damping off. See the picture below for symptoms.

carrot root with brown pythium lesions — Figure A. Carrot taproot with brown discoloured areas from Pythium infection

Garlic – The emergence rate across the province has been high with few plants showing winterkill. Plants are generally between the 3 to 6 leaf stage across the province. Expect tip burn on older leaves if temperatures below -4°C are observed. Side-dress or fertigate additional fertilizer as soon as possible, as the amount of nitrogen in applications should be reduced to avoid rough bulbs at harvest if the plants have passed the 5^th leaf stage. Scout the field every few days and look for wilted plants. Dig up suspect plants and inspect the roots and the base of the clove for Seedcorn maggot larvae, millipedes or wireworms (Figures 1-3). Many areas experienced warm night temperatures early in April which may have triggered adult leek moths to emerge from overwintering sites. Now is a good time to set up leek moth traps to monitor for the 2023 season.

**Figure 1**. Seedcorn maggot fly larvae found at the base of a wilted garlic plant in May 2019.

**Figure 2**. Millipedes feeding on a garlic clove from May 2019.

**Figure 3.** Wireworm found at the base of a garlic plant in 2017 – Joe Jubelius.

Onions – With the wet and cool weather, fields where direct seeded onion have been planted have been slow to germinate.

Potatoes – Early planted potato fields have been slow to emerge but should be progressing well with the upcoming weekend weather.

Pest Degree Day Forecasting

*NOTE: Data as of May 1st, 2023

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***	123	103	59	38	18	71	103	30
Essex*	224	184	98	66	33	120	184	54
Chatham-Kent*	203	167	91	61	33	112	167	51
Norfolk**	186	151	82	54	29	100	151	44
Huron***	163	134	78	52	25	93	134	41
Wellington**	140	116	68	50	29	82	116	43
Simcoe County***	142	121	74	51	29	87	121	43
Durham***	157	132	78	59	36	93	132	51
Peterborough	159	130	69	46	23	84	130	38
Kemptville***	155	130	71	49	28	87	130	42
Sudbury***	81	67	38	22	6	47	67	15
Timiskaming***	72	58	23	9	0	34	58	4
Lambton**	201	168	92	66	37	113	168	55
Thunder Bay	31	21	3	0	0	8	21	0
Middlesex**	179	147	83	55	30	99	147	46
Renfrew	135	122	57	31	9	73	112	22