Wet Weather = Increased Disease Pressure

Tuesday, June 6, 2023

For many across Nova Scotia this return of wet weather is a great relief to deal with wildfire issues. For grape growers, the rain means a return to new shoot growth and challenges.

Since this has been a dry spring there have been few disease infection periods for early season grape diseases. However, the frequent rainfall forecast for the next several days will ramp up the potential for infection. Last week's Vineyard Grower Q and A on Zoom discussed early season disease controls and conditions for anthracnose, downy mildew, powdery mildew and phomopsis.

Early in the season the best choices are for broad spectrum contact products as the amount of leaf area present is insufficient for use of systemic or locally systemic products. Additionally, the products do not adjust quickly for rapid shoot growth nor readily move to newly expanding leaves that will become apparent quite rapidly once the soil moisture levels are replenished.

Young soft tissue is highly susceptible, especially tissue close to the ground (suckers!) are very close to those overwintering sources of inoculum (downy mildew from old fruit infections and leaf debris from 2022) and impacted by spores falling down from the rough bark areas (overwintering ascospores from powdery mildew) and inoculum residing on 2- and 3-year-old wood (phomopsis).

Be sure to check out the tables and links on fungicide efficacy in the presentation and be sure to keep regular coverage. All growth is important, especially suckers being retrained to form new trunks for future years. 

If you have questions reach out and we will do our best to answer them Viticulture@perennia.ca.

Looking forward to seeing everyone I can next week (June 15 to 17)!


REMINDER: Join Perennia on Saturday, June 17, 10 - 12pm in Gaspereau Winery's vineyard with Kevin Ker 

Topic: how to deal with vines and blocks showing different levels of vine survival, growth, and crop levels. Time will be spent on vine nutrition choices, pest control and training/retraining strategies! 

There will also be an open question and answer session.

For more details please follow the link:  https://www.perennia.ca/eventer/vineyardgrowth/edate/2023-06-17/