Evaluation of Sweet Sorghum as a Feedstock by Multiple Harvests for Sustainable Bioenergy Production

DOI: 10.4236/jsbs.2012.24019   PDF   HTML     4,120 Downloads   7,366 Views   Citations


Sweet sorghum has become an important feedstock for bioethanol production. Total sugar yield and multiple harvests can directly affect ethanol production cost. Little is known about stem traits and multiple harvests that contribute to sugar yield in sweet sorghum. Stem traits were evaluated from 25 sweet and grain sorghum accessions. Stems were harvested twice at the soft-dough stage and the stems were pressed with a hydraulic press. Sugars in the stem juice were quantified by high performance liquid chromatography. Sweet sorghum produced five times more fresh stem weight and dry stem mass (830 gand164 g) than grain sorghum (150 gand27g). Sweet sorghum produced a much higher volume of juice and higher yield of sugars (366 ml and42 g) per stem than grain sorghum (70 ml and4 g). Significant variability in fresh stem weight (72 - 1837 g), juice volume (31 - 753 ml), sugar yield (3 - 81 g), dry stem mass (14 - 383 g), and sugar yield/dry stem mass ratio (0.11 - 0.53) per stem was detected among sweet sorghum accessions. Stem sugar yield was significantly correlated with stem fresh weight and juice volume. Sorghum was harvested twice within one growing season resulting in some sweet sorghum accessions producing double amount of sugars. Sweet sorghum produced three times more dry mass weight (bagasse) than fermentable sugar weight. To reduce feedstock cost, methods have to be developed for efficiently utilizing bagasse. Our results showed high fresh stem weight, high ratio of sugar yield to dry stem mass, and double harvests are prime traits to boost sugar yield. Sweet sorghum may be suitable for multiple harvests in certain regions of theU.S.TheU.S.sweet sorghum collection needs to be screened for acces- sions that can be harvested twice with an extended feedstock-production season and used as a feedstock for sustainable and renewable bioenergy production.

Share and Cite:

Wang, M. , Xin, Z. , Tonnis, B. , Farrell, G. , Pinnow, D. , Chen, Z. , Davis, J. , Yu, J. , Hung, Y. and Pederson, G. (2012) Evaluation of Sweet Sorghum as a Feedstock by Multiple Harvests for Sustainable Bioenergy Production. Journal of Sustainable Bioenergy Systems, 2, 122-137. doi: 10.4236/jsbs.2012.24019.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] B. Reddy and P. Redy, “Sweet Sorghum: Characteristics and Potential,” International Sorghum Millets Newsletter, Vol. 44, 2003, pp. 26-28.
[2] S. H. Taylor, S. P. Hulme, M. Rees, B. Ripley, F. I. Wooward and C. P. Osborne, “Ecophysiological Traits in C3 and C4 Grasses: A Phylogenetically Controlled Screening Experiment,” New Phytologist, Vol. 185, No. 3, 2010, pp. 780-791. doi:10.1111/j.1469-8137.2009.03102.x
[3] W. L. Rooney, J. Blumenthal, B. Bean and J. E. Mullet, “Designing Sorghum as a Dedicated Bioenergy Feedstock,” Biofuels, Bioproducts and Biorefining, Vol. 1, No. 2, 2007, pp. 147-157. doi:10.1002/bbb.15
[4] M. Calvi?o and J. Messing, “Sweet Sorghum as a Model System for Bioenergy Crops,” Current Opinion Biotechnology, Vol. 23, No. 3, 2012, pp. 323-329. doi:10.1016/j.copbio.2011.12.002
[5] Z. Xin and M. L. Wang, “Sorghum as a Versatile Feedstock for Bioenergy Production,” Biofuels, Vol. 2, No. 5, 2011, pp. 577-588. doi:10.4155/bfs.11.125
[6] D. M. Vietor and F. R. Miller, “Assimilation, Partitioning, and Nonstructural Carbohydrates in Sweet Compared with Grain Sorghum,” Crop Science, Vol. 30, No. 5, 1990, pp. 1109-1115. doi:10.2135/cropsci1990.0011183X003000050030x
[7] E. Hunter and I. Anderson, “Sweet sorghum,” Horticultural Review, Vol. 21, 1997, pp. 40-73.
[8] Y. Bian, Y. Yazaki, M. Inoue and H. Cai, “QTLs for Sugar Content of Stalk in Sweet Sorghum (Sorghum bicolor L. Moench),” Agricultural Sciences of China, Vol. 5, No. 10, 2006, pp. 736-744. doi:10.1016/S1671-2927(06)60118-1
[9] K. B. Ritter, D. R. Jordan, S. C. Chapman, I. D. Godwin, E. S. Mace and C. L. McIntyre, “Identification of QTL for Sugar-Related Traits in a Sweet X Grain Sorghum (So ghum bicolor L. Moench) Recombinant Inbred Population,” Molecular Breeding, Vol. 22, No. 3, 2008, pp. 367- 384. doi:10.1007/s11032-008-9182-6
[10] S. C. Murray, A. Sharma, W. L. Rooney, P. E. Klein, J. E. Mullet, S. E. Mitchell and S. Kresovich, “Genetic Improvement of Sorghum as a Biofuel Feedstock: I. QTL for Stem Sugar and Grain Nonstructural Carbohydrates,” Crop Science, Vol. 48, No. 1, 2008, pp. 2165-2179. doi:10.2135/cropsci2008.01.0016
[11] S. C. Murray, W. L. Rooney, S. E. Mitchell, A. Sharma, P. E. Klein, J. E. Mullet and S. Kresovich, “Genetic Improvement of Sorghum as a Biofuel Feedstock: II. QTL for Stem and Leaf Structural Carbohydrates,” Crop Science, Vol. 48, No. 6, 2008, pp. 2180-2193. doi:10.2135/cropsci2008.01.0068
[12] M. Calvi?o, R. Bruggmann and J. Messing, “Screen of Geneslinked to High-Sugar Content in Stems by Comparative Genomics,” Rice, Vol. 1, No. 2, 2008, pp. 166-176. doi:10.1007/s12284-008-9012-9
[13] M. Calvi?o, M. Miclaus, R. Bruggmann and J. Messing, “Molecular Markers for Sweet Sorghum Based on Microarray Expression Data,” Rice, Vol. 2, No. 2, 2009, pp. 129-142. doi:10.1007/s12284-009-9029-8
[14] S. C. Murray, W. L. Rooney, M. T. Hamblin, S. E. Mitchell and S. Kresovich, “Sweet Sorghum Genetic Diversity and Association Mapping for Brix and Height,” Plant Genome, Vol. 2, No. 1, 2009, pp. 48-62. doi:10.3835/plantgenome2008.10.0011
[15] M. L. Wang, C. Zhu, N. A. Barkley, Z. Chen, J. E. Erpelding, S. C. Murray, M. R. Tuinstra, T. Tesso, G. A. Pederson and J. Yu, “Genetic Diversity and Population Structure Analysis of Accessions in the Us Historic Sweet Sorghum Collection,” Theoretical and Applied Genetics, Vol. 120, No. 1, 2009, pp. 13-23. doi:10.1007/s00122-009-1155-6
[16] Y. L. Zhao, Y. Steinberger, M. Shi, L. P. Han and G. H. Xie, “Changes in Stem Composition and Harvested Produce of Sweet Sorghum during the Period from Maturity to a Sequence of Delayed Harvest Dates,” Biomass and Bioenergy, Vol. 39, 2012, pp. 261-273.
[17] T. L. Richard, “Challenges in Scaling up Biofuels Infrastructure,” Science, Vol. 329, No. 5993, 2010, pp. 793-796. doi:10.1126/science.1189139

comments powered by Disqus

Copyright © 2020 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.