Temperature – Humid and wet conditions in most growing regions earlier this week were conducive for the spread of some plant pathogens. The Durham, Huron, Peterborough, Simcoe, and Sudbury growing regions are still tracking marginally to significantly behind their average degree day accumulation; while the Chatham, Essex, Kemptville, Norfolk and Wellington growing regions have all caught up to their average degree day accumulations.
Rainfall – Precipitation in most areas varied from a quarter inch to more than two inches depending on the growing region in the past week. Norfolk County has already exceeded it’s average rainfall, while Durham, Peterborough, and Wellington are all past the three quarter mark of their average rainfall totals. Remaining growing regions range from under a quarter to the halfway point of their respective rainfall averages.
Brassica Crops –Alternaria can cause head rot in broccoli and cauliflower if spores are able to infect the beads/curds and secondary bacteria can cause rot. Calcium deficiency causing tip burning has been observed in a few fields. Continue to scout for Alternaria, black rot and fusarium wilt.
Carrot – Harvest is underway for some earlier planted fields. The second generation of Carrot Rust Fly is now active in all growing regions with exception to Chatham-Kent, Essex, Kemptville, and Norfolk. Be on the lookout for white mould between row as canopies are not closed. Continue to monitor for aster yellows, as well as leaf blights which will appear on the oldest leaves at the bottom of the canopy.
Celery – Celery leaf curl has been the predominate pathogen observed. Avoid walking through the fields when the humidity is high and the leaves are wet as celery leaf curl spores will stick to clothes and equipment. Scout for aphids, bacterial blights and leaf diseases
Garlic – When choosing a field for the 2019-2020 field season, avoid a field that has been planted in garlic, leeks or onions in the last 3 years. There will be another full day workshop in Guelph on December 4th that will cover every part of garlic production including clean seed, cultivar selection, seeding density, nutrient testing, scape removal, weed control, crop insurance, harvesting, grading, storing as well as scouting/pest management. To register, call the Agriculture Information Contact Centre at 1 877-424-1300.
Onions – The pressure of thrips has reached threshold in several regions but the general pressure this season is still low. Stemphylium leaf blight and tipburn is starting to take hold. Early transplants have been harvested in some regions and direct seeded onions are close to lodging in others.
Potatoes – Early planted fields are being harvested with most fields in or past bloom and are currently bulking. Tuber bulking is a critical time for irrigation and soil moisture. Refer to the chart below for yield impacts on dry weather conditions. Remain vigilant in scouting as some varieties begin to senesce. Remember to keep late blight specific fungicides in your spray rotation. Late Blight has been confirmed in New York State on Potatoes. The isolate has been identified as US-23 which is sensitive to Ridomil. If you suspect late blight in your field, please contact Dennis at firstname.lastname@example.org, (519) 766-5337.