What is problem with grape leaves having orange spots?

Asked October 7, 2013, 5:20 PM EDT

Hi , I'm so happy to find out this website which my problem about the grapes may be solved here !! The problem is that the leaves were starting to have some orange spots then changed into yellow color then die. The spots spread very fast. So I had to pick up the leaves which have the orange spots every day. However, it has slowed down when the weather turned into cooler. I still get some nice grapes which I made some some wine and some grape jam. They are delicious! But my concern is what I can do for the next year. I asked some people and searching on the website but I do not find out a certain answer. A very good friend who sent me this website .. :) Just looking forward to hear from you with my best regards Thank you ! Wen

Otter Tail County Minnesota grapes horticulture

1 Response

We can't be certain from viewing the photo, but our guess is that the grape leaves have been affected by a fungal disease called black rot.

Go to the following bulletins and compare what you are seeing on your grapes with the symptoms described there. If you believe the disease is black rot, follow the control recommendations noted in the bulletins.

http://www.extension.purdue.edu/extmedia/bp/bp-36.html
http://ohioline.osu.edu/hyg-fact/3000/pdf/HYG_3004_08.pdf