Biomass, sugar and ethanol yield, and water use efficiency of sweet sorghum [Sorghum bicolor (L.) Moench.] under different planting patterns.

We evaluated the changes in biomass, sugar and ethanol yield, and water use efficiency in sweet sorghum [Sorghum bicolor (L.) Moench]. Sweet sorghum was grown in the arid region of northwestern China at three different planting patterns: one (traditional planting), two and three plants per hole. Compared with traditional planting, the aboveground dry weight, total soluble sugar, calculated ethanol yield and water use efficiency were highest in the cluster planting of three plants per hole. In addition, the total soluble sugar and ethanol yield were significantly related to stem biomass under the different planting patterns. Based on the results, the cluster planting of three plants per hole plays a significant role in enhancing yield and water use efficiency of sweet sorghum. Stem biomass had the highest contribution to ethanol yield.