Thank you for your reply! The owner did not know what herbicides were sprayed this year. All of his grapevines (8 to 10 vine) are very close to the ag field and all are suffering (yellowing, lack of or withered fruit, but little to no leaf cupping/puckering). The pictures are of the vine that had the most damage.
This is also a late response. Kevin
I agree with the apple scab diagnosis. This is a severe infection, my guess is that the leaves will also have severe infections. The grapes could likely be infected with the fungus that causes black rot. Shriveled mummy berries are a common result. Both these fungal diseased need to be managed early in the growing season. The Midwest Small Fruit and Grape Spray Guide and the Midwest Tree Fruit Spray guide are two good resources. FYI, grapes are very sensitive to 2,4-D and I've seen glyphosate damage to apple trees from ag field spray drift. The damage is very apparent with cupping and misshapen leaves and petioles.
|weed id||11/15/2013||Weed Identification||1|
|Flower/Berry ID||11/14/2013||Horticulture||Herbaceous ornamentals||1|
|Pear tree disease||11/12/2013||Horticulture||Plant Diseases||2|
|Browning pine tree||11/12/2013||Horticulture||No Specialization||2|
|Bed Bug?||11/7/2013||No Specialization||1|
|Worty looking & spots on apples||10/29/2013||Fruit and Orchard||2|
|Apple and Grape Problems||10/11/2013||Fruit and Orchard||4|
|Common weed||10/8/2013||Weed Identification||1|
|Col Co Shrub identification||10/4/2013||Horticulture||Horticulture - Miscellaneous||2|