The influence of flower removal on tuber yield and biomass characteristics of Helianthus tuberosus L. in a semi-arid area

Jerusalem artichoke (Helianthus tuberosus L.) is an important source of biomass for biofuels production. To evaluate its potential as a feedstock for biofuel, calorific value, ash, and carbon (C) and nitrogen (N) contents were investigated under different flower removal treatments during 2015-2016 in the Inner Mongolia autonomous region of China. Total biomass of flower removal treatments was significantly (P < 0.05) higher than that of the control, and the highest value was obtained when 50 % of the flowers were removed (735 g plant(-1)). Tuber biomass increasing gradually as the proportion of flowers removed increased. The highest value of tuber biomass was obtained when 100 % flowers were removed (228 g plant(-1)). Tuber yield of the 33 % and 50 flower removal treatments was significantly higher than that of the 25 % flower removal treatment and control. The caloric value and N and C contents of tuber was improved while ash content of tuber was decreased with flower removal, compared to no flower removed. Total energy was the highest with removal of 50 % of the flowers 19,041 J plant(-1)). In contrast, the highest value of aboveground energy yield occurred with removal of 25 % of the flowers (7076 J plant(-1)), while underground energy yield was greatest with removal of 100 % of the flowers (4058 J plant(-1)). Removing 100 % flowers is an effective method to increase tuber yield and quality of Jerusalem artichoke in a semi-arid environment.