Relation of Ringing to Gibberellin-like Activity in Berries of Vitis vinifera L.

Abstract

IT is well known that a temporary ringing (girdling) of certain varieties of fruit trees and grapes increases the size of developing fruits. The classical theory is that the enlargement of fruit results from the greater supply of elaborated food materials trapped above the ring. Another possibility is that plant hormones trapped above the ring cause such enlargement. Ringing has long been practised to increase the size of ‘Black Corinth’ berries¹. Another method for greatly enlarging fruit of this variety is treating unringed vines with exogenous gibberellins². Because both these methods result in enlarged fruit, it seemed likely that ringing affects endogenous gibberellin content of the berries. The experiment described in this communication shows that ringing greatly influences gibberellin content.