VCR – Vegetable Crop Report – June 3rd, 2021

Temperature – Day temperatures are forecasted to range from low twenties to low thirties depending on region.

Nighttime temperatures are forecasted to be in mid-teens for most regions. The Growing Degree Day values have started tending toward the ten year average, with most regions being ahead of the average by around 50 degree days. Degree day data for each region is shown below.

Rainfall – The forecast for most regions is partly cloudy with scattered showers over the weekend with scattered thunderstorms forecasted for mid next week for most regions.

Crop Updates

Brassica Crops – Transplants are establishing well if there is adequate moisture. Wilted plants may be due to millipedes (Figure 1A) or seedcorn maggot damage and if the leaves are turning purple, the wilt may be due to wirestem, caused by Rhizoctonia (Figure 1C). If transplants have leaves cut off in the field around the soil line, dig around the plant and look for cutworm larvae. (Figure 1B). Adult click beetles(wireworms), diamondback moths, imported cabbageworms and flea beetles are active and the first-generation threshold for cabbage maggot emergence has now been reached in several counties.

**Figure 1**. Scout for transplant damage from millipedes (A), cutworms (B) and wirestem/Rhizoctonia damage (C).

Celery – The majority of transplants have been planted. The thresholds for aster leafhopper and tarnished plant bugs have been reached in all regions. Dig up wilted plants and inspect the roots/plug for cutworm larvae.

Carrot – Carrot weevils are active and currently laying eggs. Use carrot bait traps to monitor for them as they enter the field. We have passed the degree day threshold for carrot rust fly and small numbers have been caught on orange sticky traps in some fields (Figure 2). Black cutworm has been identified in some vegetable fields. Keep an eye out for cutworm damage in carrots fields like clipped leaves and cut-off plants.

**Figure 2**. Carrot Rust Fly caught on orange sticky card

Garlic – Plants across the province are starting to send out the scape leaf on hardneck cultivars. Irrigation may be required for bulbs to size well in areas that have had little precipitation over the past month. Reports of leek moth damage and catches in delta cards are low for the past week. Depending on the area, the second flight of leek moth will be active over the next two to three weeks. Tipburn is widespread across the province this year and may be due to frost damage, lack of moisture or herbicide injury. It is difficult to find plants that are still green to the tip.

Onions – The majority of seeded onions are in the second leaf stage. The degree day threshold for onion maggot has been reached in all growing areas and maggots are actively feeding in several areas (Figure 3). With the cooler weather over the past two weeks, some onions are showing signs herbicide damage which is likely due to the lack of a waxy layer. Control volunteer onions in neighbouring fields as this can be a source for fungi inoculum like Stemphylium or pests like onion thrips. Thrips have been found over the past two weeks on volunteer onions. Black cutworms are active and can cause damage that looks like the onion has been cut with scissors above the soil line (Figure 4). Dig around suspect plants to look for cutworm larvae within the soil.

Figure 3. Onion maggot larvae found in SW Ontario on June 2nd, 2021

**Figure 4**. Black cutworm damage to a direct seeded onion

Peppers – Peppers are being planted now and are about 60% done. Cutworms and wire worms can both cause stand losses in peppers. Keep an eye out for damage to transplants at the soil line.

Potato – Colorado potato beetles are emerging and active. We are looking for Colorado Potato Beetle samples again this year to test for insecticide resistance. If you are finding a lot of beetles and are interested in participating, please reach out to Dennis (dennis.vandyk@ontario.ca 519-766-5337) to arrange a submission. Watch for emergence issues and keep an eye out for early season seed issues like fusarium, Rhizoctonia, soft rots and seed-borne late blight.

Sugarbeets – Are up and stands look good. Cutworms can cause early season damage to seedlings. Look for plants that have a clean “cut” at the soil line.

Tomatoes – Tomato transplants are in the ground now. Keep an eye out for early season pests that can cause significant stand losses. Cutworms and wireworms are active right now. Keep an eye out for damage to transplants at the soil line. Colorado potato beetle is also coming out and can cause significant damage to transplants. Look for bright orange eggs on the underside of leaves and defoliation caused by larva and adults.

Pest Degree Day Forecasting

*NOTE: Data as of June 3rd, 2021

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*	648	572	360	254	143	425	572	212
Chatham-Kent*	589	516	328	232	116	385	516	192
Norfolk**	565	494	307	211	98	365	494	170
Huron***	525	460	297	214	111	345	460	179
Wellington**	470	403	242	160	70	289	403	127
Simcoe County***	501	431	258	173	80	309	431	139
Durham***	491	424	246	169	76	297	424	138
Peterborough	456	387	216	139	57	265	387	108
Kemptville***	563	493	301	203	96	360	493	165
Sudbury***	401	345	212	152	72	250	345	125