With mature vines a good rule of thumb is not to allow them to develop more than two clusters per shoot. An acceptable taste is the main criterion for table use. On a vine that is not overcropped, the berries of black varieties lose their red color and white varieties will change from green to golden yellow. Ripe berries will soften and seeds become brown. Determining the harvest of wine grapes requires either experience or a means of measuring both sugar and acid content.
Bunch grapes require frequent and thorough spraying to avoid diseases and insects.
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