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VCR – Vegetable Crop Report – July 12, 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 – July 12, 2019

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Temperature – Hot weather in the past week has given crops a good stretch of sunlight and heat units to continue their growth progression. Most regions are still behind their 10-year average degree day accumulations with exception to Essex and Norfolk which have caught up to their respective averages, while Chatham is only marginally below its average. Planting is now completed for long season crops and harvest of some early transplanted crops is now underway in some regions. 

Rainfall –  Rainfall has varied from region-to-region this week with unstable weather systems causing severe afternoon thunderstorms to pop up and drop up to an inch of rain per day in some areas, while others are now regularly irrigating fields due to a lack of precipitation. Chatham, Kemptville, and Norfolk  are approaching their halfway points for average July rainfall while the rest of the growing regions are at a quarter or less of their average July rainfall totals. 

Crop Updates

Brassica Crops – Diamondback moths levels and flea beetles are now decreasing with aphids, imported cabbageworm taking their places. Zebra caterpillars have been observed in several fields and infestations are typically sporadic and do not warrant control measures.  Keep scouting for Alternaria and incorporate all reside in the soil from a block once it is harvested.

Carrot – With this stretch of hot weather, we’ve been seeing some heat canker in carrot fields due to hot soil temperatures. Irrigation is important to mitigate some of that heat stress and keep the plants from shutting down.

Celery – Black heart, caused by a calcium deficiency has been seen in some transplants as well as some carrot weevil damage. Severe infestations of root knot nematode (picture below) can cause stunting and leaf dieback. Use a shovel to dig up stunted plants and check the roots for nodules.

celery-root-knot-nematode.jpg

Garlic – The second generation of leek moth has started as trap captures have spiked in many areas. With the crop approaching harvest shortly, be mindful that Matador has a 14 day PHI while other products have a 3 day PHI (Delegate WG, Success and Entrust) or no PHI (Bioprotec CAF). Destroy any plants you find that have leek moth damage as managing leek moth levels this year will likely reduce the amount of potential damage seen next year. Zebra caterpillars (picture below) have been found in a few garlic fields this week; infestations are typically sporadic and do not warrant control measures. To read more about Zebra caterpillars see: https://onvegetables.com/2012/06/29/zebra-caterpillars/

zebracaterpillars.jpg

Onions – Onion maggot and onion smut damage has been common this season while populations of onion thrips has been low.  When populations reach over a threshold of 1 thrips/leaf, two applications of Movento has been found to provide the best control.  Conditions have not been favourable for downy mildew development.

Potatoes – We are seeing Colorado potato beetle larvae that have hatched and started feeding. Remember to rotate insecticide groups for any foliar applications. We are still looking for some samples to test for insecticide resistance so if you have some CPB feeding in your fields, please contact Dennis at 519-766-5337. During this time of rapid growth, remain vigilant on fungicide applications to ensure new leaves are protected. No late blight spores have been found in the spore traps and no late blight confirmations have been reported in surrounding states. We’ve seen some early blight lesions show up on some older leaves. With the hot and dry conditions we’ve had the last week or two, it’s important to maintain soil moisture levels during critical growth stages. Refer to the chart below for the impact of dry weather on yield loss.

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*126411558546814609511155599
Chatham-Kent*113010227355663408261022491
Norfolk**110710047255623378141004490
Huron***894799547402212624799338
Wellington**922829576434244654829372
Simcoe County***901807557417233634807357
Durham***957863613475281690863412
Peterborough854759505360178585759299
Kemptville***1004910655504292735910432
Sudbury***766687476360199540687308

*- 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

EssexDDJuly12EssexTPJuly12

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Chatham-Kent County

ChathamDDJuly12ChathamTPJuly12

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Norfolk County

NorfolkDDJuly12NorfolkTPJuly12

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Huron County

HuronDDJuly12HuronTPJuly12

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Wellington County

WellingtonDDJuly12WellingtonTPJuly12

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Simcoe County

SimcoeDDJuly12SimcoeTPJuly12

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Durham County

DurhamDDJuly12DurhamTPJuly12.jpg

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Peterborough

PeterboroughDDJuly12PeterboroughTPJuly12

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Kemptville

KemptvilleDDJuly12KemptvilleTPJuly12

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Sudbury

SudburyDDJuly12SudburyTPJuly12

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