In this article:
The relationship between the morphology of sultana canes and their fruit production was studied to determine the value of external cane characters for the selection of pruning wood. Canes were rated on the following as desirable characters: well-ripened appearance, good diameter throughout, internodes not too long, and presence of persistent laterals. Canes tended to be more productive the higher their rating.
Productivity was not directly affected by the age of the wood from which the canes arose nor by their having borne fruit. In each season nodes with persistent laterals were superior to nodes with deciduous laterals, and these in turn were superior to nodes without laterals, but there were no changes in the proportions of node types from season to season corresponding to changes in fruitfulness.
It is concluded that the appearance of the cane is the only factor worth taking into account when pruning.
No simple visual method was found which could replace microscopical examination in estimating fruitfulness to forecast potential crop.
Studies on the Sultana Vine. VI. The Morphology of the Cane and its Fruitfulness
1958, Australian Journal of Agricultural Research, vol 9, issue 3, pages 328 – 338