In this article:
Ringing (removal of a ring of bark from the base of the shoot or trunk) is a common viticultural practice for improving fruit yield or quality in certain grape varieties.
It is presumed to act by interrupting the movement of nutrients within the plant; however, it is now evident that endogenous hormone levels also are affected by the process.
This paper reports on changes in the cytokinins extracted from shoots of non-fruiting grape vines after ringing.
The Effect of Ringing on Cytokinin Activity in Shoot of the Grape Vine
1972, Journal of Experimental Botany, vol 23, issue 76, month 4, pages 768 – 774
Please note accessing PDF may be slow, thank you.