Problem on grape clusters
My grape vines are loaded with tiny grapes but now the grapes look to be opening up into a fluffy flower. I'm afraid I am losing my grapes. What is happening. They had seemed so healthy.
Without an image, the best I can determine is Botrytis cinerea fungus.
You may want to take the grapes into your local County Extension Office. They can help with any local disease issues.
Here is a link to help you locate your closest office.