Answer: Grapes need to be pruned in order to produce fruit. Prune by selecting canes that grew the year before and prune them back so they only have two buds. These buds will produce canes that will produce fruit. If you had fruit on your vines but it disappeared, I'd suspect birds or racoons got to them before you did! Not much you can do about it except prune so there will be enough fruit for you and for the local wildlife.
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