In this article:
A comparison of Sultana clones selected for yield showed that selection based on 9 or more years’ yield was more effective than based on 4 years.
The main effect of from the longer term selection was avoidance of leafroll, but there may also be a minor genetic component. No clone superior to those already in use were found.
A Comparison on 182 Sultana Clones Selected for Yield
1979, Australian Journal of Agriculture Research, vol 30, pages 1111-1122
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