Effects of Row Spacing on Growth, Yield and Quality Parameters of Sweet Sorghum

Abstract

A two-year field experiment was conducted in Thessaly, Central Greece, in order to evaluate the effect of row spacing on several growth and yield parameters of sweet sorghum. In particular, two row spacings were tested: wide row spacing (WRS) at 0.75m and narrow row spacing (NRS) at 0.375m. During the growing period, crop growth in terms of plants' emergence, plants' height, panicle appearance, while stalk sugar content, dry biomass and total sugar yield were also evaluated. In addition, plant material was analysed to assess the potential effects of the treatments on stalk quality. The results showed that with the appropriate cultural practices, sweet sorghum can yield over 40 Mg ha-1 of dry matter and over 18 Mg ha-1 of total sugar yield under Greek conditions. Narrow row spacing resulted to higher plant population and productivity in terms of dry matter and total sugar yield (61% and 37% increase, respectively) in the first year, but without any statistical significant difference compared to the wide spacing in the second year. The compositional analysis of the crop samples revealed significant effects of row spacing on water soluble matter, cellulose and hemi-cellulose content revealing a beneficial effect of narrow row spacing on the quality and consequently ethanol production.