Temperature – The cool wet spring has continued to affect temperature and degree day accumulation in almost all of the growing regions of Ontario. Most of the counties are marginally to significantly behind their respective growing degree day averages of the previous 10 years with exception to Essex and Huron counties which are at average, and above average respectively. 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 – A drier weekend in most regions allowed entry to plant some fields, however in most counties planting is still underway. Regular rainfall has continued every few days and pushed Essex, Kemptville, and Sudbury to the half way point of their 10-year averages for the month of June. The remaining regions have received between a quarter and third of their respective 10-year average rainfall amounts for this month.
Brassica Crops – Early planted transplants are establishing well and flea beetles have been active in some fields. Diamondback moths as they are now active and the degree day threshold for cabbage maggot emergence has been reached in Essex, Chatham-Kent, Norfolk and Kemptville. Scout for tarnished plant bugs, cabbageworms, aphids and thrips.
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 – Earliest transplants are establishing well given they are not sitting in water. Scout for tarnished plant bugs and carrot weevils as they will be likely emerging and present around field borders. The degree day threshold for aster leafhoppers and tarnished plant bugs has been reached in all counties except for Sudbury.
Garlic – Scaping of hardneck varieties will be commencing over the next two weeks. Avoid using sickle bars mowers to cut the scapes, as they often cut leaves that will reduce the yield potential, as well as spread pathogens between plants. Better yields have resulted when the scape is snapped an inch above the youngest leaf. Pulling scapes instead of snapping can cause the upper leaves to lose support and fall over causing pre-mature senesce. Avoid applying any nitrogen past the 5th leaf stage as this has been found to cause ‘rough’ bulbs with cloves forming outside the main bulb wrapper. Adult leek moth trap counts are very low this week in most counties suggesting that we are between the two main flights.
Onions – The earliest seeded onions at the 3rd to 5th leaf stage however most fields are averaging around the 2nd leaf stage. The first generation of onion and seedcorn maggot flies are active in most areas and low levels of thrips and pink root have been found in transplants.
Peppers – Peppers are now about 55-60% in. Some cutworm damage is being seen.
Potatoes – 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 – About 95% of tomatoes are now in. Insect damage is down compared to levels seen a few weeks ago. Be on the lookout for wireworm and black cutworm damage, especially on sandier soils.
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||210-700||138-156||128||40||314||200||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.