Temperature – The cool wet spring has continued to affect temperature and degree day accumulation in almost all growing regions of Ontario with all counties marginally, to significantly behind their 10-year average degree day accumulations. While some regions are now receiving near average temperatures, the lack of sun, and late planting dates has slowed the growth and development of many crops in most planted areas.
Rainfall – Rainfall has generally slowed in most regions this week and planting in most regions is now near completion, or completed already. Many counties are now approaching their 10-year average rainfall totals for June with exception to Peterborough, Huron and Simcoe counties.
Brassica Crops – Diamondback moths are now active in fields. Also keep an eye out for flea beetles especially during higher temperatures when they are more active. Continue to scout for cabbageworm, tarnished plant bugs, aphids, and thrips. The first generation of cabbage maggot has now emerged in Southwestern Ontario, and severely infested plants may be found to be wilted in hot weather.
Carrot – Weevils are active and laying eggs in most regions of the province. Monitor for adults to see if your fields have reached the spray threshold. Read about the latest in carrot weevil control in this post – Update on Carrot Weevil Control.
Celery – Transplants are establishing well in fields. Carrot weevils have been active and the degree day threshold for aster leafhoppers and tarnished plant bugs has been reached in all growing regions.
Garlic – Scaping of hardneck varieties has started in several counties. Be sure to avoid damage to an leaves while scaping. Avoid using sickle bar mowers to cut the scapes, as they often cut leaves which will reduce the bulb yield potental, as well as spread plant pathogens, including viruses between plants. Better yields have resulted when the scape is snapped an inch above the youngest leaf as pulling scape instead of snapping can cause upper leaves to lose support and fall over leading to pre-mature senesence. While in the field or scaping, scout for holes and damage to the scape (Fig. 1A) and leaves due to leek moth as adult leek moth trap counts have been elevated this week. If you find a plant wit holes or damage, tear apart the leaves and look for light-green larvae about half an inch in length (Fig 1B).
Onions – Earliest seeded onions are up to the 6th leaf stage while most fields are averaging around the 3rd leaf stage. Without the waxy build up on leaves, herbicide damage has been common in most fields. The fist generation of onion and seedcorn maggot are now active, or are past their peak flight in all counties with exception to cabbage maggot in Sudbury. Cutworm damage in several direct seeded fields. The cooler, wet weather has kept the levels of thrips low thus far into the season. Thrips are usually first detected along field borders. Onion fields next to hay or overwintering rye are at a greater risk as thrips move once the hay or rye is cut. Given the weather, also keep an eye open for botrytis and downy mildew
Peppers – Peppers are about 90% planted and plant to be finished by June 22nd. Peppers are experiencing more Pythium and/or Fusarium stem rots, which is likely attributed to the wet weather and delayed planting this year.
Potatoes – Be vigilant in scouting for late blight. Early season conditions have been favorable for any seed piece or cull pile infections to sporulate. Overwintering Colorado Potato Beetle adults are active, mating and laying eggs currently. Scout your fields, especially around the border to determine if your field is at threshold or if your seed-piece/in-furrow insecticide is effective. In order to monitor whether the CPB are becoming resistant to our registered insecticides, AAFC will be conducting a CPB resistance survey again this season. If you see any CPB populations in your potatoes, please contact Dennis (519-766-5337) and we can come and take a sample to be tested.
Tomatoes – Tomato planting has now concluded. There has been a higher incidence of Pythium and/or Fusarium stem rots this season compared to years past, which is also likely due to the wet weather and delayed planting this year
Pest Degree Day Forecasting
Select a region below for the latest weather, crop and pest degree day information:
|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|
*- Bivoltine region for ECB. First Peak Catch: 300-350 DD, Second Peak Catch 1050-1100 DD
**- Overlap region for ECB. First Peak Catch : 300-350 DD Second Peak Catch 650-700 DD, Third Peak Catch 1050-1100 DD
***-Univoltine region for ECB. Peak Catch 650-700 DD
Use these thresholds as a guide, always confirm insect activity with actual field scouting and trap counts.