In this article:
Dormancy and bud burst are studied for Sultana vines in the Murray Valley, Australia. The vines are in deep dormancy at the beginning of autumn and the intensity of dormancy increases gradually during autumn and winter.
Bud burst of cuttings taken during the dormant period occurs the more rapidly the higher the temperature at which they are held.
There is evidence to suggest that sultanas have no chilling requirement and no clear distinction between organic and enforced dormancy.
Treatment with ethylene chlorhydrin is effective in breaking dormancy. Removing the outer bud scales or soaking buds in water decreases the intensity of dormancy.
The pattern of bud burst found on canes in the field is established on pruned canes at least one month before the shoots appear.
Both auxin and gibberellin is found to delay bud burst and reduce the proportion of buds which burst.
Dormancy and Bud Burst in Sultana Vines
1961, Vitis, vol 3, issue 1, pages 1 – 14