Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Abstract Only
Publication Acceptance Date: 10/6/2007
Publication Date: 11/1/2007
Citation: Wilson, J.P., Endale, D.M., Schomberg, H.H., Dale, N., Wang, D., Hanna, W.W., Vencill, W. 2007. Hybrid and proximate composition effects on ethanol yield from pearl millet. http://aaic.org/07program.htm.
Interpretive Summary: not required
Technical Abstract: Investors have committed to the construction of new ethanol plants in the southeast in spite of the grain-deficit status of this region. Pearl millet is likely to be a viable supplemental feedstock. The DDGS has a greater nutritional value, resulting in a lower net cost of ethanol production from pearl millet. Because the fermentation process concentrates mycotoxins in grain, DDGS from pearl millet will have lower mycotoxin levels due to its resistance to fungi that produce aflatoxins and fumonisins. No information exists on the differences in fermentability among pearl millet hybrids, or genotype x environment interactions in feedstock quality. The objective of this preliminary study was to assess experimental pearl millet hybrids for genotype and environment effects on yield, proximate composition, ethanol yield, and fermentation efficiency. Yield trials were planted at Moultrie, Tifton, Watkinsville, and Newton GA in 2006. Fertilizer was applied at 88 kg N/ha. Grain was combine-harvested, and yields were corrected to 15.5% moisture. Grain was evaluated for protein, fat, and starch content on a dry basis, and for fermentation efficiency. Experimental hybrid (606 x 2304) was among the top yielding hybrids at all locations. Across all locations, hybrid (606 x 2304) had 17% greater yield than TG102. (606 x 2304) had 40% higher 100 grain weight, 7% lower protein content, similar fat, 50% greater starch, and 14% greater fermentation efficiency compared to TG102. For all hybrids, ethanol yield was correlated with starch content (R=0.91, P<0.0001) and fermentation efficiency (R=0.37, P=0.03), but was negatively correlated with protein content (R= -0.88, P<0.0001). It will be possible to select hybrids that produce higher levels of ethanol for the developing bioenergy industry in the southeast. The negative correlation of ethanol yield with protein content may affect the economics of fermentation by reducing the DDGS quantity, and may also affect grain value for alternative use markets.