197: Managing the Sour Rot Disease Complex in Grapes

<p class="MsoNormal"><span style= "mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">What makes Sour Rot so challenging for wine grape growers is that it is a disease complex.</span> Hans C. Walter-Peterson, Viticulture Extension Specialist, Finger Lakes Grape Program, Cornell Cooperative Extension explains that <span style= "mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">Sour Rot comes in late season after ripening.<span style= "mso-spacerun: yes;"> </span> Yeasts get into the berries and ferment the sugar out in the vineyard. Bacteria follow up, feasting on the alcohol, converting it into acetic acid – an unwelcome component in winemaking. And, the disease is spread rapidly by fruit flies.</span></p> <p class="MsoNormal"><span style= "mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">In this interview Hans shares methods to reduce Sour Rot disease pressure by managing increasingly resistant fruit fly populations, leafing to encourage fewer berries at fruit set, the correct way to drop fruit, and timing antimicrobial and insecticide sprays to Brix to maximize effectiveness.</span></p> <p class="MsoNormal">Cornell Cooperative Extension is trialing non-chemical control practices including UV light for sterilization and hormonal sprays plus a disease model is under development with Penn State University.</p> <h2><span style= "mso-fareast-font-family: 'Times New Roman';">Resources:</span></h2> <ul> <li class="MsoNormal"><a href= "https://www.vineyardteam.org/resources/resource-library/product-assurance-and-business-sustainability.php?id=609"> 17: New Discoveries about Sour Rot – Megan Hall (Podcast)</a></li> <li class="MsoNormal"><a href= "https://www.vineyardteam.org/resources/resource-library/pest-management.php?id=910"> 117: Grapevine Mildew Control with UV Light - David Gadoury (Podcast)</a></li> <li class="MsoNormal"><span style= "mso-fareast-font-family: 'Times New Roman';"><a href= "https://www.vineyardteam.org/resources/resource-library/soil-conservation-and