Hello Wisconsin Fruit News subscribers and welcome back to Notes from the Field: A Grower’s Perspective! I had my seventh chat with Philippe on July 13…
Just as Philippe and his crew were preparing for more irrigation at Wollersheim, they received 2.7 inches of rain. This rain brings a huge relief to Philippe and many other crop growers across Wisconsin, as they have battled an extensive drought this summer. This rain also gives the wells a break, which have been in high demand all summer.
With dry and hot weather this season, Philippe noticed foliar and fruit powdery mildew infections in his vineyard. The powdery mildew appeared to be the worst in blocks without drip irrigation installed. Varieties displaying the most severe symptoms included Foch and LaCrosse. Philippe and I discussed how this season’s conditions are ideal for the powdery mildew pathogen. Unlike many of the other fungal pathogens we encounter in Wisconsin vineyards (ex. Phomopsis, downy mildew, etc.), powdery mildew can be severe in dry, hot weather; I write more about this here. In terms of powdery mildew management at Wollersheim, Philippe is using stylet oil as well as combinations of FRAC 3 and FRAC 7 fungicides. Insect pressure has been low, and Philippe can count the Japanese beetles on two hands. With recent rains, it is unclear how that will influence pest pressure in the vineyard. Herbicide application may be needed next week, as the recent moisture has allowed the weeds to take off.
If the drought conditions continue, and growers are unable to irrigate, Philippe encourages fruit removal based on shoot size. For shorter shoots, he removes all fruit, as there may not be enough foliage to support the berry growth and only further stress the vine. This is especially the case for 1–2-year-old vines in these stressed conditions where there is not enough foliage to keep up with the demands needed to support vine growth. For longer shoots, he will leave one or two clusters as more foliar tissue is available to support berry development.
With another dry growing season in Wisconsin, Philippe speculates that mulching will be an important practice in the future to maintain soil moisture. Current cracks in the soil indicate how extreme this year’s drought has been. Within the next week Philippe expects to see the first sign of veraison in the vineyard; in previous years he has observed pink berries by the third week in July. With veraison right around the corner, many management practices will shift and intensify to protect the fruits.
That’s all for now! Check out the notes from my next chat with Philippe in the 8th issue of Wisconsin Fruit News on July 28. If you missed any of my previous chats with Philippe, you can find them here.
This article series is NOT intended to be prescriptive for other vineyards. It is simply an opportunity for our readership to hear from other growers about their experiences growing fruit crops in Wisconsin.
Growing the same crop does not always justify the same practices. Management decisions at your farm should be tailored to your operation and take into consideration location, regional climate, disease and pest history of your vineyard, and your varieties.
The mention of a product is NOT an endorsement. Always follow the instructions on product labels and consult weather stations (ex. NEWA) in your area for current weather forecast and disease and pest prediction models.This article was posted in Notes from the Field and tagged Leslie Holland, Notes from the Field, Philippe Coquard.