The effect of sowing and harvest date and cultivar on inulin yield and composition of chicory ( Cichorium intybus L.) roots

Abstract

The effects of sowing and harvest date on root yield, total sugar content and inulin chain length were assessed in trials during 1992 and 1993 with three chicory varieties. In both years the sugar yield was at least 30% higher at an early sowing date (before mid-April) than at a sowing date 1 month later. The total sugar content depended most on the cultivar. The average chain length of the inulin polymers was more than 2 U of fructose longer at the harvest around mid-September than at the harvest around mid-November. The sugar yield was only 10% higher at the late than at the early harvest date. The breakdown of the inulin chains of the variety with a high inulin content, as affected by the harvest date, was slower than the breakdown of the inulin chains of the varieties with a low inulin content. The content of free fructose and sucrose increased and the content of free glucose and inulin decreased with harvest time.