Location: Coastal Plain Soil, Water and Plant Conservation Research
2020 Annual Report
Objectives
Objective 1. Determine the ability of cotton germplasm to withstand soil water deficits, identify and characterize drought tolerance genes, and develop innovative management practices for optimizing use of the improved genotypes in production systems.
Sub-objective 1A. Identify genotypes with fiber length stability when subject to water deficit stress during fiber elongation.
Sub-objective 1B. Identify cotton genotypes that withstand soil water deficits.
Sub-objective 1C. Evaluate variable rate irrigation using crop feedback for site-specific irrigation management of cotton in the Southeastern U.S. Coastal Plain.
Objective 2. Develop and evaluate new cotton germplasm with increased genetic diversity, improved fiber quality, and lint yield stability traits.
Approach
New technologies and new genetic resources are needed to help the nation’s cotton producers face increasing economic and environmental challenges. The proposed research will contribute to the industry’s ability to meet the nation’s fiber needs and become more competitive in world markets. Since water deficit stress is a serious limitation to cotton production, much of this research will be aimed at finding solutions to lessen the impact of this environmental stress. The research has two objectives: (1) determine the ability of cotton germplasm to withstand soil water deficits, identify and characterize genetic variation for drought tolerance, and develop innovative management practices; and (2) develop new cotton genetic resources with increased genetic diversity, improved fiber quality, and lint yield stability. In this research, we will conduct genetic studies on the effect of water deficit stress on fiber length and yield, determine how best to use proximal sensing data collected from high throughput phenotyping platforms, design innovative double crop cotton production systems, and develop new cotton genetic resources. Research methods include field experiments and statistical analyses using modern analytical equipment and innovative analytics. Research products include new knowledge of genetic variation for fiber length stability under water deficit stress, protocols for using proximal sensing data collected from high throughput phenotyping platforms as a water deficit stress breeding selection tool, new water efficient cotton cropping systems, and high quality cotton germplasm containing exotic introgression. All segments of the cotton industry and southern rural economies will benefit from the findings of this research.
Progress Report
Water deficit stress research. The research consists of two 2-year field studies initiated in 2019. This year’s update primarily pertains to the first field study which is designed to determine the impact of water deficit stress on fiber length development. Bolls were intensively sampled among a group of diverse genotypes in well watered and water deficit stress field plots every five days through the first 35 days of fiber development in 2019 and 2020 field trials. Fiber length measurements are in progress across the time series to develop fiber length growth curves for each genotype. This research supports Subobjective 1A of the project plan to identify genotypes with fiber length stability when subject to water deficit stress during fiber elongation. The second, two-part field study is ongoing to determine if canopy temperature can be used to determine genotypic differences in drought tolerance. Intense canopy temperature data collection was initiated in a field trial consisting two genotypes differing in their drought tolerance to determine soil water levels, crop growth stage, and local weather conditions which provide the best opportunity to differentiate genotypes differing in drought tolerance. This research supports Subobjective 1B of the project plan to identify cotton genotypes that withstand soil water deficits.
Cotton cropping system research. Research was initiated in 2018 to evaluate Brassica carinata as a winter crop in rotation with cotton. B. carinata is a multi-use oilseed crop used to produce an aviation biofuel for jet engines. B. carinata also provides a source of protein meal for animal feed. In 2020 as part of the USDA-NIFA Coordinated Agricultural Project ‘Southeast partnership for advanced renewables from carinata-SPARC’, the third year of B. carinata breeding line evaluations was conducted in Florence, South Carolina. Although, the 2018 field trial sustained significant freeze damage that resulted in 100% plant death, results in 2019 and 2020 demonstrate the potential for B. carinata production in the northern region of the southeast USA. In 2020, the average yield for the trial in Florence, South Carolina, was the third highest out of fifteen sites planted across Alabama, Florida, Georgia, Mississippi, North Carolina, and South Carolina. In addition, cotton was planted in 2020 following B. carinata harvest to determine the potential of B. carinata as a cover crop and/or double crop with cotton. This research supports Subobjective 1C of the project plan to develop innovative management practices for optimizing production systems by determining the feasibility of B. carinata as a new part of the cotton production system in the northern southeast U.S.
Cotton germplasm development research. A two-year, multi-location (Florence, South Carolina, Maricopa, Arizona, and College Station, Texas) field trial was conducted to evaluate advanced breeding lines containing 50% exotic landrace parentage. Preliminary analysis of agronomic and fiber quality performance data indicates five germplasm lines with 50% exotic landrace parentage display excellent agronomic and fiber quality performance and will be officially released. The release of these five germplasm lines is in the process of being approved and once finalized, seed will be provided to private and public breeding programs as a source of new breeding parents. This will result in a significant research accomplishment next year. Also, a project to develop exotic introgression populations containing different levels of exotic introgression is ongoing. Exotic lineages of 25%, 50%, and 75% are being advanced. The introgression populations developed by the end of this project plan will provide a rich genetic resource to further study exotic landrace introgression in cotton. Together, this research supports Objective 2 of the project plan to develop and evaluate new cotton germplasm that will provide the cotton industry new breeding stock containing previously untapped and valuable genetic diversity.
Accomplishments
