Effect of excessive soil moisture stress on sweet sorghum: Physiological changes and productivity

Sweet sorghum [sorghum bicolor (l.) moench] is a potential bioenergy feedstock. research explaining the response of sweet sorghum to excessive soil moisture (em) stress at different growth stage is limited. to investigate the effect of em stress on sweet sorghum antioxidant enzymes,osmotic regulation,biomass,quality,and ethanol production,an experiment was conducted in a glasshouse at the national sorghum improvement center,shenyang,china. sweet sorghum (cv. liaotian1) was studied in four irrigation treatments with a randomized block design method. the results showed that the protective enzyme,particularly the sod,cat and apx in it,was significantly affected by em stress. em stress deleteriously affected sweet sorghum growth,resulting in a remarkable reduction of aboveground biomass,stalk juice quality,stalk juice yield,and thus,decreased ethanol yield. em stress also caused significant reduction in plant relative water content,which further decreased stalk juice extraction rate. sweet sorghum grown under light,medium,and heavy em treatments displayed 5,19,and 30% fresh stalk yield reduction,which showed a significant difference compared to control. the estimated juice ethanol yield significantly declined from 1407 ha-1 (under optimum soil moisture) to 1272,970,and 734 l ha-1 respectively. © 2016,pakistan botanical society. all rights reserved.