Biomass production and stability of five energycane cultivars at two latitudes in Georgia, USA

Energycane (Saccharum hyb.) could be a viable bioenergy crop for the Southeast USA. Five energycane cultivars were planted in 2008 at a northern (Watkinsville, GA) and a southern (Tifton, GA) site, and were grown for seven years to compare biomass yields. Plots were arranged in a four replicate randomized complete block design at each site.  Energycane was grown under rainfed conditions with 90–112 kg ha-1 N applied annually. Plant height was recorded at least monthly, and stalks were sampled to determine juice volume and Brix (estimate of sugar concentration) at harvest. Whole plots were mechanically harvested each year after killing freeze and weighed to determine biomass yields. Biomass yield and mature plant height were strongly correlated at both Tifton (r = 0.746) and Watkinsville (r = 0.727). Biomass yields peaked in year four at Tifton (39.8 Mg ha-1) and year five at Watkinsville (30.5 Mg ha-1), but local weather conditions had a greater influence on yields than stand age. Day-l...