Black Rot on Grapes

Asked July 3, 2016, 1:19 PM EDT

Can you suggest a treatment plan for Black Rot on Purple Wine Grapes- This year I trimmed the vines thinking the Black Rot needed to have less moisture around the vine. However I still have grapes that are shriveling up and turning black again. After reading though the sites directions I am still left with questions. What fungicide should I use next year and how should I use it. I am a beginner when caring for these plants so I could use some detailed directions, in layman terms, and some brand names of a fungicide to purchase. Thank you for your guidance, Michelle

Dane County Wisconsin grapes horticulture

1 Response

Here is a link to an eXtension article on black rot on grapes. It discusses fungicides and management plans. Black rot, like all blights, survives on tissue of its victim. That means plant debris, roots as well as the part above ground. It overwinters in its host and emerges in the spring to begin producing spores. You need to get rid of all plant debris and infected plant parts as soon as symptoms appear.
I don't know if the chemicals listed in the article are available to homeowners.Here is a link to your local extension office and ask to speak to the person who could help you with a treatment plan. Also, you can consider replacing your grapes with a resistant variety. Fungicide treatments can be expensive and the chemicals are unhealthy in some cases.