Stomatal Sensitivity of Grapevine Varieties Relates to Changes to Berry Growth and ABA During Water Deficit.

Varieties with earlier stomatal closure under water deficit show greater reductions in berry size and increases in ABA, highlighting stomatal regulation's role during drought.

• Why it matters: Understanding how different grapevine varieties respond to water stress is crucial for improving drought tolerance and optimizing berry quality under changing climate conditions.
• What they did: Researchers applied short-term severe and long-term water deficits before and after veraison to four grapevine varieties, measuring physiology, ABA levels, and berry growth and composition.
• The result: Stomatal regulation primarily affects berry growth and ABA during drought, while berry sugar and acid contents remain largely unaffected by varietal stomatal responses, informing targeted drought management strategies.