translocation, plant physiological process whereby soluble materials such as dissolved salts, organic materials, and growth substances are moved around the vine in the phloem. (The phloem tissue is in the outer part of the trunk or stems, and so can be disrupted by cincturing.) Sucrose is the principal form in which carbohydrates are moved, and the phloem sap also contains amino acids and organic acids, inorganic nutrients, plant hormones, and alkaloids. Examples of translocation are the movement of inorganic nutrients absorbed by roots from the soil to other parts of the vine, for example potassium going into the fruit, which may prejudice wine quality. Translocation also includes the important movement of sucrose formed by photosynthesis away from the leaves to the fruit which will eventually become alcohol in wine. From the point of view of wine, the translocation of sucrose, malic acid, tartaric acid, elements, and compounds containing nitrogen during ripening are crucial to the chemical composition of grapes, and thus to eventual wine quality.
