Plant guide:ð Grapes
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Growth
Poor Fruit Set and Shatter on Grapevines
Commonly affects: Vitis vinifera, V. labrusca (Grape)
Many flowers fail to develop into berries, leaving unusually loose, sparse clusters with far fewer grapes than expected.
Potential Causes
- 1Cool, wet, or windy weather during bloom disrupting pollination
- 2Nutrient imbalances, particularly boron or zinc deficiency, affecting flower and fruit development
- 3Excessive vine vigour diverting energy from fruit set to vegetative growth
Solution Steps
- 1Avoid disturbing the vine during the brief bloom period if possible
- 2Apply a foliar boron and zinc supplement in early spring if deficiency is suspected
- 3Manage vine vigour through appropriate pruning and avoiding excess nitrogen
- 4Accept that some shatter is normal in certain varieties and challenging weather years
Prevention Tip
Boron deficiency is an under-recognised but common cause of poor fruit set in grapes â a foliar micronutrient spray before bloom can make a real difference.
