Management practice effects on corn grain ethanol yield and ethanol byproduct quality

Management practice strategies for corn [Zea mays L.] have traditionally been focused on maximizing grain yield. Due to the dramatic increase in corn grain usage for ethanol production it is important to understand how corn management strategies affect ethanol yield and byproduct quality. Four hybrids in 2007 and six hybrids in 2008 were grown at Bradford Research and Extension Center near Columbia, MO using five planting dates to determine whether planting date has an impact on grain yield, ethanol yield and corn kernel characteristics. Whole kernel samples were measured for seed composition using a FOSS Infratec 1241 Grain Analyzer. Averaged across all hybrids, the variation between the highest and lowest yielding planting dates were 89% in 2007 and 50% in 2008. The June planting date recorded the lowest yields for both years. Planting date affected dry grind and wet mill ethanol yield along with starch, protein, and lipid concentrations; however the effect of delaying planting was inconsistent between years. Ethanol yield varied by 5.9% and 3.5% in 2007 and 2008 between all combinations of hybrids and planting dates using the dry grind method while wet mill ethanol yield varied less than 3% for both years. Kernel starch concentration was not a good predictor of ethanol yield while kernel protein concentration was positively correlated with the dry grind and negatively correlated with the wet mill ethanol yield for