In this article:

The paper investigates the relationship in grapevines between fruit area, fruit and vine growth, and fruit composition.

Total leaf area was altered, either by defoliation or by covering the leaves with aluminium bags, half the total leaf area or complete defoliation at veraision.

All leaf elimination treatments reduced berry weight and soluble solids concentration significantly.

All leaf elimination treatments resulted in higher total acidity in the fruit in the early stages of ripening, but only when apical leaves were eliminated did it remain higher until maturity.

Fruit from vines completely defoliated at veraison had drastically lower soluble solids concentration, but less severely reduced berry weight.

Approximately 10cm2 of leaf tissue per gram of fruit was required to mature the crop fully without decreasing the soluble solids in the berries.

Influence of Defoliation, Leaf Darkening and Cluster Shading on the Growth and Composition of Sultana Grapes

1970, American Journal of Enology and Viticulture, vol 21, issue 1, pages 26 – 36

csiro 189

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