Sweet Sorghum, a Potential Biofuel Crop for the Mid-Atlantic.

Sweet Sorghum [Sorghum bicolor (L.) Moench] has high potential as a feedstock for clean bioenergy production.  A three-year (2009-2011) field study was conducted under irrigated and dryland conditions to determine the viability of growing sweet sorghum as a biofuel feedstock in sandy Mid-Atlantic soils of the Coastal Plain. Principal components analysis was used to analyze the three years of field trials.  This allowed us to reduce the number of variables from eight to three (PC1-3).   These three new variables explained 82% of the variance in the data set.  PC1 explained 35.2% of the variance and had high positive loadings for Biomass, Juice Volume, Cane Height and Total Sugar; this component therefore represents vegetative yield.  The following cultivars gave the highest overall yield and would therefore be excellent feedstock candidates for ethanol production: ‘Dale’, ‘Della’, ‘Keller’, ‘KN Morris’, ‘M81E’, ‘Theis’ and ‘Topper’.  PC2 explained 29.0% of the total variance and had high positive loadings for Seed Mass and Bagasse.  ‘High Cane II’, ‘Mennonite’ and ‘Sugar Drip’ had the highest scores for PC2, but these cultivars exhibited low vegetative yield.  There appeared to be an inverse relationship between vegetative yield and seed production.  PC3 explained 17.6% of the total variance and had a high positive loading for Brix, thus PC3 represents the Sugar Content of the juice.  The cultivars with the highest Brix were ‘Dale’, ‘KN Morris’ and ‘Simon’.  Although there was considerable variation among years, which we mainly attributed to weather, there was little variation between irrigated and dryland plots.