In this article:
Canes of comparable origin can differ in both appearance and in fruitfulness.
It was thought the orientation of the growing cane in the gravitational field could be a contributing factor and investigation was carried out to to test the effect of gravity on sultana shoots.
Unlike fruit trees, in sultana fruitfulness and bunch primordium were severely depressed when canes were diverted from their normal direction of growth.
It is speculated that the grape vine differs from fruit trees in its reaction to gravity because it is a climber under natural conditions.
Effect of Direction of Growth on Sultana Canes
1960, Nature, vol 185, issue 4710, month 2, pages 394 – 395
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