Location: Crop Genetics and Breeding Research2013 Annual Report
1a. Objectives (from AD-416):
To develop and evaluate bermudagrass, napiergrass, pearl millet, and rhizoma peanut for forage production and for alternative uses in the southeastern U.S.; to enhance bioenergy production from warm-season grasses; and to apply molecular genetic technology to improve grass species adapted to the southeastern U.S.
1b. Approach (from AD-416):
Develop and select improved populations and germplasms of bermudagrass for forage, bioenergy, and turf; develop and select improved populations and germplasms of napiergrass for forage and bioenergy; develop and select improved populations, inbreds, and hybrids of pearl millet for forage, bioenergy, and wildlife; and select improved rhizoma peanut germplasms for forage. Evaluate genotype and production effects on ethanol production from pearl millet; assess genotypic differences in bermudagrasses, napiergrass, and pearl millet for conversion to fermentable product or through thermochemical techniques to syngas; and improve selection efficiency for superior forage and cellulosic feedstocks. Measure genetic diversity within bermudagrass, napiergrass, and pearl millet using molecular markers; and identify associations of molecular markers in bermudagrass and pearl millet with traits important for forage or alternative uses.
3. Progress Report:
Significant portions of the overall project outline were completed. Manuscripts were published and results disseminated. Other portions of this project have been adjusted to current priorities and are present in the new CRIS project that began in January 2013. Some of the sub-objectives were not completed due to the release of one SY early in the five-year plan and then the retirement of a second SY prior to the end of the 4th year within this project. This bridging project was replaced by new project #6602-21000-024-00D.
1. Determination of Appropriate Production Practices of Bioenergy Feedstock Grasses for the Southeast. Two high yielding perennial grasses have shown promise as biomass feedstock in the Southeast. However, specific cultivars and production practices need to be determined to guide growers. ARS researchers at Tifton, GA grew napiergrass (also called elephantgrass) in a non-irrigated study with either poultry litter or inorganic fertilizer. In general, nitrogen removal exceeded the amount applied, suggesting that higher fertilizer application rates are necessary. Total soil carbon increased by over 3000 kg ha-1 among the three treatments indicating that use of napiergrass as a biomass feedstock would be either carbon neutral or carbon-positive relative to petroleum. In another study, the ARS researchers grew different breeding lines of energycane (high-yielding high-fiber biomass feedstock derived from sugarcane) to evaluate conversion to ethanol over time. A laboratory procedure converted the biomass from nine different energycane breeding lines that were sequentially harvested to ethanol. Ethanol yield from higher fiber energycanes was more stable over multiple harvests because they contain fewer free sugars. These higher fiber energycanes also produced higher yields in Tifton, GA compared to sugarcane types. Information from these two studies will help direct the bioenergy industry and growers on types and methods of high-yielding biomass grasses for the Southeast.
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