Crop growth and development and yield of Jerusalem artichoke were studied in field crops harvested periodically during 2 years. Investigations were carried out on two topics: (i) cultivation of different Jerusalem artichoke cultivars, (ii) optimization of analytical procedures for sugars determination in order to select cultivar and harvest period for optimization of sugar production. Agronomic investigations have shown this crop to have a significant advantage over other crops with respect to biomass yield, which can reach 100-130 t/ha in November for the best cultivars. Advanced analytical procedures, such as HPLC, Mere used to analyse the hydrolytic breakdown of inulin during the vegetation period of Jerusalem artichoke tubers. The depolymerization of the polyfructosans resulted in juices with different polymer content according to rite harvest date. That led to a decrease of the fructose/glucose ratio (FIG) of the total sugars from II to 3 during the harvest period. Tuber utilization for sugar or alcohol production should take into account this phenomenon. (C) 1997 Elsevier Science Ltd.