I have had a grape vine for years without any problems but this year the new grapes are covered with dust HELP

Question

The dust is white and can brush off thank you.

Answer 1

Are you sure it is dust, there are several reasons for this condition and these can be found easily on the net. there are even some that are desirable to wine makers namely nobel rot, you would have to do the research as there are to many to list and without seeing it in person not really a way to distinguish between them.