Spotted, curled grape leaves

Asked October 21, 2016, 11:29 AM EDT

I planted 3 varieties of grapes during the winter dormant period (2015-2016). They took off nicely, then we experienced flooding and rainful beyond what is typical for the Houston area. Although the grapes are on high ground, there was no way to protect them from the daily rain. In late Spring, their growth almost immediately became stunted and I noticed brown spots and erosions on the leaves of all of the plants - the Blanc du Bois affected the most (2 plants died), the champanelle not as much (one died), the Black Spanish the least. I have also noticed miniscule black bugs and a web-like material on the underside of the leaves, eventually causing the leaves to curl around them. I am guessing these are unrelated problems....

I noticed a fungus farm at the base of one of the grape plants and from this, decided that the spots must be related to fungal growth. I have been spraying the leaves with a copper-based fungicide about once every week to 3 weeks. This has seemed to keep the plants from dying. My questions: Is there something I can do over the winter dormant period to prevent fungal growth in the Spring? Am I wrong in my supposition that this is fungal? Should I be treating in some other way? Are these mite-like creatures harmful to my plants and should I treat for them (I am currently just cutting off any affected leaves I see)?

Thanks for your help!

Montgomery County Texas

3 Responses

Thank you for the question. I am including two links that may help you manage your problems with the grapes. Fungal issues have been extreme this year. Rain and other forms of moisture contribute to many issues. These two resource will help you identify the insect and other issues and offer suggestions for control. If you have any additional questions, please do not hesitate to contact me. MP
http://winegrapes.tamu.edu/grape-growing/diseases-pests-problems/grape-disease-management/
http://winegrapes.tamu.edu/grape-growing/diseases-pests-problems/grape-insect-pest-management/

You posted the same link twice. Please provide the second link. Thank you!

http://winegrapes.tamu.edu/grape-growing/
I tested the links and both went tot he correct pages. One page is on diseases (fungal) and the other is for insects.
The above link will take you to a main page. You can then click on GRAPES, it will provide you with a drop down menu for each area of interest. Select the"Disease, Pest & Problems" and it will bring another menu to select the appropriate topic. Hope this helps.. MP