2009 Annual Report
1a.Objectives (from AD-416)
1) Optimize cotton production systems for the southeastern U.S.A. that incorporate soil conservation and sustainable technologies, such as winter cover crops, reduced tillage, and poultry waste. Subobjectives are (a) to develop improved management practices in cotton production systems that include poultry litter or materials derived from poultry litter; (b) assess the feasibility of using late-summer legumes for soil improvement in rotations with cotton; and (c) relate water use to within-canopy boll size and quality distribution in a conservation production system and determine how patterns of water use affect whole crop fiber quality of genotypes differing in genetic potential for fiber properties..
2)Identify sources of traits to improve cotton performance in production systems in the southeastern USA and introgress the associated genes into enhanced germplasm suitable to be made available to cotton breeders for variety development.
1b.Approach (from AD-416)
Cotton production and processing are an important part of the economy of the southeastern U.S.A., and development of sustainable production systems and improved germplasm will be key to sustaining and enhancing the industry. We intend to conduct research that will result in improved cotton production systems that provide higher yield, improved fiber processing quality, and lessen risk of non-point source pollution to the environment. We will.
1)identify management options and search for genetic traits that can be used to overcome factors that inhibit optimum productivity in conservation systems;.
2)evaluate the agronomic and environmental value of potential resources (poultry litter and products extracted from litter; summer legume cover crops) available to growers in the southeast; and.
3)evaluate genotypes and develop germplasm with enhanced fiber yield for profitable production and improved fiber properties for efficient yarn and textile processing into consumer acceptable products. Methods consist of field, greenhouse, and laboratory investigations. The expected benefits of this research are crop management systems with higher yield, more environment-friendly growing practices, and the development of germplasm with improved fiber properties which will benefit all segments of the cotton industry, including cotton farmers, agricultural supply companies, ginners, and mills.
This project was terminated in January of this year and is followed by the new project 6657-21000-006-00D ‘Genetic and cultural practice improvement for sustainable cotton production.’
Yield and fiber quality field performance data were collected on 90 preliminary and 108 advanced cotton breeding lines. Three of the advanced breeding lines were selected for further performance testing in the South Carolina Official Cotton Variety Trial and the Regional Breeder Testing Network Trial to determine if they should be officially released. In addition, agronomic and fiber quality data were collected from a field study designed to evaluate the type of gene action controlling yield and fiber quality properties. This information will be useful to public and private cotton breeders working on developing new cotton varieties that will be grown by producers.
We initiated a pilot experiment to identify members of the water channel or aquaporin gene family of cotton. More than 50 aquaporin genes were tentatively identified. Results from this pilot experiment were presented at the Cotton Beltwide Conference and offer cotton researchers potential target genes for improving cotton water use efficiency.
In our cropping systems research, we evaluated the potential of using sunn hemp as a potential bioenergy crop. Sunn hemp is a fast-growing plant that can be grown in rotations with other crops in the southeast. Preliminary data indicate it has about 3-5% higher energy content per kilogram dry weight than corn stalks and switchgrass; other potential bioenergy feedstocks. In this research, we compared sunn hemp to cowpeas (a widely grown summer legume in the southeast) and found that sunn hemp had higher ash content after burning than cowpeas, but the ash content (in some cases) was lower in concentrations of minerals known to reduce thermochemical conversion process efficiency. Pyrolytic degradation (burning) of both legumes revealed that sunn hemp began to degrade at higher temperatures and released more volatile matter. This volatile matter would be amenable to conversion processes to generate either heat or synthetic fuels.
In previous research, we determined that phosphorus recovered from animal manures using technologies developed at this location is an effective fertilizer under greenhouse conditions. We determined in that research that large particle size (2-4 mm) of calcium phosphate recovered from swine wastewater was only slowly available and therefore appears to be a potential slow-release fertilizer. We continued this line of research with a study designed to evaluate the availability of two particle sizes of phosphorus recovered from swine wastewater under field conditions. Data collection from this experiment is continuing.
Improving the Efficiency of Cotton Breeding. Selecting the best combination of parents to develop new cultivars is a major goal of cotton breeders. Historically, cotton breeders have relied on pedigree information and performance data to select parents. We conducted this research to show that molecular DNA information can also be used in combination with pedigree and performance data to increase the chance of developing an improved cultivar. A set of 80 potential parents from the Pee Dee cotton germplasm collection were analyzed using this approach and the data were provided to the cotton breeding community. Cotton breeders can use this information to better select parents and more efficiently develop high quality and high yielding cultivars that will ultimately enhance cotton farm profits and productivity of textile mills.
Understanding Cotton Fiber Property Variability. Reducing the variability of fiber properties in harvested cotton is important to textile processors. A better understanding of the causes of the variability is needed in order to design management schemes to reduce it. In this research, we determined.
1)adequate soil water through the boll development period provides far more uniform cotton fiber in terms of fiber length, fineness, sugar content, and salt content, and.
2)environmental conditions during cotton boll development had the same influence on two cotton varieties that differed in time to harvest maturity. These results are important because they will be used by cotton researchers to develop cotton cultivars and management systems with reduced fiber quality variability; thus providing textile mills higher quality cotton that will allow for more efficient processing of cotton into yarn and will result in higher quality fabrics. Also, it will make U.S. cotton more competitive in world markets.
Bauer, P.J., Foulk, J.A., Gamble, G.R., Sadler, E.J. 2009. A comparison of two cotton cultivars differing in maturity for within-canopy fiber property variation. Crop Science. 49:651-657.
Park, W., Zhai, J., Lee, J. 2009. Highly efficient gene silencing using perfect complementary artificial miRNA targeting AP1 or heteromeric artificial miRNA targeting AP1 and CAL genes. Plant Cell Report. 28:469-480.
Wallace, T.P., Bowman, D., Campbell, B.T., Chee, P., Gutierrez, O.A., Kohel, R.J., McCarty, J., Myers, G., Percy, R., Robinson, F., Smith, W., Stelly, D.M., Stewart, J.M., Thaxton, P., Ulloa, M., Weaver, D.B. 2009. Status of the USA cotton germplasm collection and crop vulnerability. Genetic Resources and Crop Evolution 56:507-532.
Campbell, B.T., May, O.L., Howle, D.S., Jones, D.C. 2009. Registration of PD 99035 germplasm line of cotton. Journal of Plant Registrations 3(1):73-76.