Increased berry size of Fantasy table grape by reducing the size of individual clusters
There are several methods used to increase the size of the berries in a cluster of table grapes. These are reducing the size of the grape cluster, reducing the number of grape clusters on the vine, applying hormones like gibberellic acid and girdling of stems.
The easiest to use for homeowners is to reduce the number of clusters on the vine and reduce the size of each cluster. By reducing the size of each cluster, the remaining berries increase in size.
We try to reduce the number of clusters by eliminating these clusters when we see them blooming or reduce the number of canes or spurs at the time of pruning.
The cluster size is reduced by pinching off the bottom third of the cluster where you see the arrow. This is done as soon as the berries set from the flowers or when the berries are the size of BB’s. This results in a cluster than is rounded in shape, with fewer berries thus each berry gets more from the vine resulting in larger berries but fewer of them.