Which factor is a limit to bud fruitfulness that involves light exposure?

• A. Temperature
• B. Shading
• C. Soil pH
• D. Wind exposure

Answer: (B)

Light exposure drives photosynthesis, supplying the carbohydrates that grapes use to form and set flower buds. When parts of the canopy shade the leaves, photosynthesis drops and so does the carbohydrate reserve available for bud development. That reduced energy supply during the bud formation period lowers how many buds become fruitful, limiting bud fruitfulness. In viticulture, this is why canopy management to prevent shading—balancing leaf area and light interception—is important for optimizing fruitfulness. Temperature, soil pH, and wind exposure can influence vine growth in other ways, but they don’t specifically tie light exposure to bud formation in the same direct way.