Chicory Root Yield and Carbohydrate Composition is Influenced by Cultivar Selection, Planting, and Harvest Date

Abstract

Chicory (Cichorium intybus L.) is not extensively grown in the USA for fructan production, and there is limited information available on the effect of cultural practices on root yield. Three field experiments were conducted from 1995 through 2002 to determine the influence of planting and harvest date and cultivar on yield and carbohydrate composition of chicory roots. Different chicory cultivars were planted from the first of April through mid‐May and were monitored for plant stand, leaf area, and bolting during the growing season and for root yield in late summer, fall, and the following spring. Roots were characterized for carbohydrate composition with high performance anion exchange chromatography. Plant stands and root yields were similar when chicory was planted in early and mid‐April, but root yields declined 35% when planting date was delayed until mid‐May. Harvest date was closely associated with root yield and total sugar content. Root yields increased 84% from 1 September to 15 November. Total sugar content was 197 mg g−1 fresh weight when roots were harvested in early November. The degree of fructan polymerization (DP) was also influenced by harvest date. The percentage of longer chain‐length fructans increased until the first fall frost (−3°C). Forty‐five days following the first frost, the percentage of longer chain‐length fructans in the DP > 20 category declined from 23 to 13% of the total carbohydrate, and the percentage of shorter chain‐length fructans in the DP 3 to 10 category increased from 36 to 45% of the total carbohydrate. Chicory stand, leaf area, bolting percentage, root yield, total sugar content, and degree of fructan polymerization were influenced by cultivar selection. Results from 7 yr of research indicated that chicory could be successfully grown in western Nebraska.