Which factor is commonly listed as causing low carbohydrate levels in roots, trunk, and branches?

• A. Water stress
• B. Mildew
• C. Excessive leaf removal
• D. High crop loads in prev season

Answer: (A)

Carbohydrate reserves in roots, trunk, and branches come from the sugars produced by photosynthesis in the leaves and then stored or remobilized in woody tissues. When water is scarce, stomata close to limit water loss, photosynthesis drops and the leaf sugar supply falls. At the same time, drought can reduce phloem transport by lowering turgor pressure, so even available sugars are less effectively moved to storage tissues. The result is lower carbohydrate levels in those woody parts. While disease, leaf removal, or heavy previous-season crops can influence carbon balance in some situations, the link between water stress and a direct, widespread drop in stored carbohydrates makes drought the most commonly cited cause.