Can girdling be used to increase berry size?
We have limited experience with the application of girdles for increasing the berry size of Redglobe. Growers are generally hesitant to girdle own-rooted Redglobe grapevines due to their often moderate vigor. In addition, previous work has indicated that berry set girdles are only marginally effective for increasing the size of seeded table grape cultivars. Another factor which should be considered is that fruit on vines girdled at berry set is believed to be more sensitive to sunburn than fruit on ungirdled vines. The latter is especially critical for Redglobe due to the cultivar’s high susceptibility to fruit sunburn damage. In 1992 we conducted an experiment to determine the influence of trunk girdle timing on Redglobe table grapes. The trial was conducted in an own-rooted Redglobe vineyard located near Exeter, CA. Vines girdled at berry set (sizing girdle) and at fruit softening (maturity girdle) were compared to ungirdled vines. Each treatment was replicated 10 times using single
