EVOLUTION OF FRUCTOSE YIELD COMPONENTS IN CHICORY (CICHORIUM-INTYBUS L) DURING THE HARVESTING CAMPAIGN

In a varietal design for studying the evolution of fructose yield components in relation to the harvesting period, 12 varieties were sown on May 1, 1987, and cropped on October 15, November 15 and December 15, 1987. As for fructose proportion, fructose yield, potassium and amino-N contents, no significant varietal effect has been detected during the whole harvesting campaign. Moreover, for fructose content and total sugar content, the month effect is not significant. However, the commercial varieties have been classified into three groups: heavy root and poor fructose content, low root and high fructose content, and medium. This medium group provides the best compromise between root weight and fructose content. In 1987, chicory generally maintained its yield at a high level until November while decrease in fructose content is counter-balanced by a glucose content increase. From November to December, under the influence of climatic factors, net yield decreases rapidly and then stops when the mean sugar yield per sample becomes stable as the glucose content increases at the expense of fructose content.