Spacing Effect on Energy Cane Growth, Physiology, and Biomass Yield

Energy cane is a specialized sugarcane (Sacharum spontaneum L.) hybrid developed for high lignocellulosic biomass for biofuel production. The optimum planting spacing for energy cane is not known; hence, it has been planted with sugarcane planting spacing. We examined the effect of six plant spacings derived from three inter-(1.22, 1.52, and 1.83 m) and two intra-row (0.61 and 0.91 m) spacings on energy cane growth, physiology, and biomass yield. Energy cane was planted in fall 2012, was harvested after establishment in 2013, and was allowed to ratoon for biomass yield in 2014 and 2015. The plant spacing had varied effects on energy cane growth and physiology, but no effect on biomass yield. Wide spacing resulted in increased tiller and leaf numbers, but spacing had no effect on other growth and physiological parameters at the p < 0.05 level. The results suggested that energy cane possesses the ability to adjust plant growth according to plant spacing without compromising its biomass yield and can effectively use wide spacing (1.83 x 0.91 m) commonly adopted for sugarcane planting. Wide spacing can reduce seeding cost and energy during planting and will allow the use of existing sugarcane farm machinery for energy cane production. The high biomass yield (18.8-25.1 Mg ha(-1)) of energy cane obtained in this study also suggests that energy cane can be successfully produced for lignocellulosic feedstock.