Feasibility of Obtaining Two Crops of Sweet Sorghum for Ethanol, MAC, 2006

Sweet sorghum has potential as an energy crop in the Southwest since, compared to corn, it requires less fertilizer and water, is cheaper to grow, and requires less energy to process into ethanol. The purpose of this study is to determine the feasibility of obtaining two crops of sweet sorghum from a single seeding. Two cultivars of sweet sorghum were seeded at early and late dates at the Maricopa Agricultural Center in 2006. Two crops of sweet sorghum were obtained in our study with a short season cultivar Bundle King, but not with the longer season cultivar MMR 327/36. The ethanol yield of Bundle King of 213 gal/acre from two crops planted on April 7 was not significantly greater statistically than the ethanol yield of 162 gal/acre from a single crop planted on June 1. Bundle King is an inherently low yielding variety, as are most short season sweet sorghum cultivars that may be used for double cropping. Thus, the problem with double cropping is identifying a suitable cultivar along with increased harvest costs, despite the advantage of providing a more even supply of feedstock to an ethanol plant.