RT Journal Article SR Electronic T1 Influence of Environment on Metabolism of Organic Acids and Carbohydrates in Vitis Vinifera. II. Light JF American Journal of Enology and Viticulture JO Am J Enol Vitic. FD American Society for Enology and Viticulture SP 119 OP 129 DO 10.5344/ajev.1964.15.3.119 VO 15 IS 3 A1 Kliewer, W. M. A1 Schultz, H. B. YR 1964 UL http://www.ajevonline.org/content/15/3/119.abstract AB Radioactive CO2 was administered to shoots of White Riesling growing in the field af two stages of maturity and under three different light conditions: ful sunlight and shaded vines receiving approximately 20 and 30% of full sunlight. The amount of C14O2 incorporated into organic acids and sugars from both immature and nearly ripe berries grown under different light conditions was determined over a period of 32 to 80 hours.Berries from 21% sun had more label in the organic acid fraction and less in the sugar fractions than berries from 30% or 100% sun. The amount of C14O2 incorporated into malic acid was usually relatively greater from shaded berries; tartaric acid, on the other hand, contained a greater proportion of the label with 100% sun.Immature shaded berries contained a relatively greater amount of label in sucrose and a decreased amount in glucose and fructose, but this relationship was reversed in mature shaded berries. Mature shaded berries contained a relatively smaller amount of label in sucrose than unshaded berries. The proportion of activity in glucose and fructose was not greatly influenced by the amount of sun.