2007 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. 4.Accomplishments Identification of Genetic Variability for Response to Supplemental Irrigation Within the Pee Dee Cotton Germplasm Collection: Genetically improving cotton to be more efficient in the use of water will be enhanced by an understanding of how cotton genotypes differ in yield and fiber quality response to water application. We found significant variation among 13 Pee Dee germplasm lines for response to supplemental irrigation for a number of agronomic and fiber quality traits. The information gained in this research can be used by cotton breeders for developing better varieties for both irrigated and rainfed cotton production systems. The research contributes to the goal of increasing crop productivity and quality in production systems in a sustainable manner under the Sustainable Cropping Systems component of National Program 305. Mill Processing Performance of Transgenic Cotton Cultivars: Production of high quality cotton is vital for domestic mills and for exporters of this crop. Concerns about the mill performance of transgenic cultivars were addressed in this research. Working with scientists from the USDA-ARS Cotton Quality Research Laboratory and Clemson University, we found little difference between transgenic cultivars and their parent cultivars for mill processing performance, yarn quality, or fabric quality. Since a majority of the cotton varieties grown in the US have transgenic traits, this information is important to the industry since it demonstrates that mill performance is not compromised with this technology. The research contributes to the goal of increasing crop productivity and quality in productions systems in a sustainable manner under the Sustainable Cropping Systems component of National Program 305. 5.Significant Activities that Support Special Target Populations None. 6.Technology Transfer Number of active CRADAs and MTAs 11 Number of web sites managed 1 Number of non-peer reviewed presentations and proceedings 7 Number of newspaper articles and other presentations for non-science audiences 2 Review Publications Foulk, J.A., Bauer, P.J., Akin, D.E., Busscher, W.J., Camp Jr, C.R., Ayala Silva, T. 2007. Effect of tillage on double-croppped flax/cotton production and fiber properties. Online. Crop Management doi:10.1094/CM-2007-0803-01-RS. Baenziger, P.S., Russell, W.K., Graef, G.L., Campbell, B.T. 2006. Improving lives: 50 years of crop breeding, genetics and cytology. Crop Science. 46:2230-2244. Bauer, P.J., McAlister III, D.D., Frederick, J.R. 2006. A comparison of bollgard/glyphosate tolerant cotton cultivars to their conventional parents for open end yarn processing performance. Journal of Cotton Science. 10:168-174. Bauer, P.J., Mcalister III, D.D., Roof, M.E. 2006. Evidence that light stink bug damage does not influence open end yarn processing performance. Journal of Cotton Science. 10:161-167. Campbell, B.T., Bauer, P.J. 2007. Genetic variation for yield and fiber quality response to supplemental irrigation within the Pee Dee Upland cotton germplasm collection. Crop Science 47:589-597. Dhungana, P., Eskridge, K.M., Baenziger, P.S., Campbell, B.T., Gill, K.S., Dweikat, I. 2007. Analysis of genotype-by-environment interaction in wheat using a structural equation model and chromosome substitution lines. Crop Science 47:477-484.