Changes in the glucose: Fructose ratio during the growth period of the razaki grape

The fructose content of table grapes is of importance, especially for cultivars growing in cold climates. The glucose: fructose ratio (G: F ratio) in the table grape Vitis vinifera L, cv. Razaki during the entire growth period was determined by polarimetric and volumetric methods, This ratio was found to be 1.95 at the beginning of the growth period and 1.55 in the final stage of growth (over‐ripe), with an excess of glucose throughout. The G:F ratio decreased until the middle of August and was almost constant thereafter, Acidity decreased until mid‐September, when the berries reached maximum weight.