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VCR – Vegetable Crop Report – August 14, 2019

The VCR (vegetable crop report) is a weekly update which includes crop updates, weather and growing degree summaries for various vegetable growing regions across Ontario. Continue Reading VCR – Vegetable Crop Report – August 14, 2019

Ontario DD Map - August 14Temperature – Most regions had somewhat cooler weather within the last week although degree day progression was not seriously impacted in most areas. Most regions are still behind the average degree day accumulation for this point in the year with exception to the Chatham-Kent, Essex, Kemptville, Norfolk, and Wellington areas. Harvest of early-mid season crops continues to be underway and are now making their way to fresh market.

Rainfall – Precipitation totals were generally fairly low across most growing regions again this week with exception to those between central and Eastern Ontario on August 8. Regions range from about the half way point of their respective 10-year average for rainfall, to well below their 10-year rainfall average and approaching near drought conditions. 

Crop Updates

Brassica Crops – Weather has been conducive for bacterial pathogens such as black rot. Alternaria has been causing damage to broccoli and cauliflower heads and with prolonged periods of high humidity, head rot has been developing. Calcium deficiency causing tip burning has been observed in a few fields.

Carrot – The second generation of Carrot Rust Fly is now active in all growing regions with exception to Essex, Chatham-Kent, where the upper limit of the degree day threshold has now been exceeded and Sudbury, where threshold has not yet been met. Keep an eye out for aster yellows when scouting as trap counts of aster leafhoppers continue to be elevated. Also continue to monitor for 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 bacterial blight as well as celery late blight / Septoria.

Garlic – Garlic curing works best in an area that has good ventilation, low relative humidity and that is not in full sun. Curing is complete when the cloves are pulled apart and base of the stem close to the basal plate is dry, the center of the cut stem is hard and the neck is constricted at the bulb. Curing quickly (within a week) will reduce the likelihood of survival for garlic mites. Once cured, table stock can be kept at a temperature 0.5°C at a relative humidity of 50-70% and planting stock can be kept at 10°C (up to 18°C) at a relative humidity of 55-65%. To learn more about garlic production, we are offering a 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 contact centre at 1 877-424-1300.

Onions – Stemphylium leaf blight and bacterial rot is continuing to develop. The pressure of thrips is starting to build in some areas but counts are still very low. Count the number of thrips by pulling leaves apart and counting the grey adults or small yellow nymphs. The spray threshold for onion thrips is 1 thrips/leaf from an average of 50 plants. For example, if 325 thrips are counted on 50 plants at the 8th leaf stage, the average level of thrips would be 325/50/8 = 0.8 thrips/leaf. Keep an eye open for feeding damage to the onion leaves and look for larvae causing damage. Leaf damage could be caused by yellow woollybear caterpillars or leek moth.

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. Verticillium early dying symptoms are showing up in some fields, keep an eye out in susceptible varieties for early symptom development, for more information, see the Ontario Crop IPM page at http://www.omafra.gov.on.ca/IPM/english/potatoes/diseases-and-disorders/verticillium.html Continue to be vigilant for late blight as spores continue to be found in spore traps in many Ontario counties. Late Blight symptoms have been found in Pennsylvania, New York, and Wisconsin; although Ontario and Michigan have still not had any symptoms show up yet. If you suspect late blight in your field, please contact Dennis at dennis.vandyk@ontario.ca, (519) 766-5337

Growth Stage Soil Available Water Requirement Yield Losses IF Available Water Below Required Levels 
Growth Stage I Sprout Development 75% available soil waterShort periods of drought stress do no reduce yields
Growth Stage II Vegetative Growth 75% available soil water5%
Growth Stage III Tuber Initiation80% available soil water10%
Growth Stage III Tuber Initiation80% available soil water10%
Growth Stage IV Tuber Bulking 90% available soil water40-60% Highest demand for water. Adequate water is necessary for high yield. Dry conditions favour tuber malformations
Growth Stage V Tuber Maturation 60-65% available soil water Water deficit causes tuber dehydration 

 

 

Pest Degree Day Forecasting

PestCarrot Rust FlyOnion Maggot Carrot WeevilAster LeafhopperTarnished Plant Bug Cabbage Maggot Seedcorn MaggotEuropean Corn Borer 
THRESHOLD329-395, 1399-1711210-700, 1025-1515138-156, 455+128+40+314-398, 847-960, 1446-1604200-350, 600-750, 1000-1150See legend below
Essex*1919177613771137817150617761022
Chatham-Kent*17441603121798264413411603874
Norfolk**17031568119096162313121568855
Huron***1453132597476346110841325666
Wellington**14891363101180350111221363710
Simcoe County***14831356100780150411171356708
Durham***15571431108187757111921431781
Peterborough1417129093672543110491290632
Kemptville***16061478112590758412381478803
Sudbury***130711958857034309821195618

*- 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.

Select a region below for the latest weather, crop and pest degree day information:

Essex County

Chatham-Kent County

Norfolk County

Huron County

Wellington County

Simcoe County

Durham County

Peterborough

Kemptville

Sudbury

Essex County

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Chatham-Kent County

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Norfolk County

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Huron County

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Wellington County

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Simcoe County

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Durham County

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Peterborough

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Kemptville

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Sudbury

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