Grape Vines Struggling with Disease
That looks like Anthracnose.
A few grape varieties get it pretty bad.
What variety is it.
With this wet spring it is a good year for diseases
Thank you Mark. The variety is Himrod. Is happened last year as well. Should I pull out the vines and start over? Is there something I can treat it with?
Himrod is a nice table grape, but it is very susceptible to anthracnose.
As bad as the vines look getting rid of the disease would be hard as it overwinters on infected portions of the vine. Controls include pruning out infected portions of the vine. If they look really bad I would pull the vines and start over.
Regular sprays of fungicides from when the shoots are about one inch long. Timing should be every 10 to 14 days between sprays. Spray more frequently under rainy conditions. Captan is effective but it will wash off during rainy condition like the two inch rains we have received this year. Materials containing pyraclostrobin are very effective and are absorbed into skin of the fruit so they will not wash off.
The main focus of sprays is the early shoot growth period through bloom until 3 or 4 weeks after boom. If you can keep the disease from becoming established then later controls should not be needed.