Source: UNIVERSITY OF GEORGIA submitted to NRP
DEFINING THE CONTRIBUTIONS OF PRODUCTION ENVIRONMENT AND VARIETY TO FIBER YIELD, SEED COMPONENT YIELDS, AND CROP PERFORMANCE IN SUBSEQUENT GROWING SEASONS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1030455
Grant No.
2023-78412-39695
Cumulative Award Amt.
$294,000.00
Proposal No.
2022-07298
Multistate No.
(N/A)
Project Start Date
Apr 15, 2023
Project End Date
Apr 14, 2026
Grant Year
2023
Program Code
[A1811]- AFRI Commodity Board Co-funding Topics
Recipient Organization
UNIVERSITY OF GEORGIA
200 D.W. BROOKS DR
ATHENS,GA 30602-5016
Performing Department
(N/A)
Non Technical Summary
Cotton is the number one fiber crop in the world, with fiber being the primary source of income for growers. However, seed is also a valuable co-product of fiber production used for cattle feed or food processing purposes. Importantly, oil is the most economically valuable component of seed. Its content in cotton seed can be altered by cultivar selection and production environment, which could affect economic returns for the producer and may influence seedling vigor for the subsequently planted crop. However, the extent to which cultivar selection and production environment contribute to the total value of the crop (fiber, oil, and protein) and seedling vigor of the subsequently planted crop has received virtually no attention in the peer reviewed literature. The research proposed here will address this glaring knowledge gap by using a combination of small-plot and large-scale on-farm research to specifically address the effects of cultivar selection and production environment on fiber yields, seed component yields, and vigor and yield of subsequently planted crop. This will maximize crop value for the producer (high oil yields without fiber yield penalties) while simultaneously ensuring that seed produced in these high-yield environments exhibit acceptable vigor and productivity for cotton growers.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
20517101020100%
Knowledge Area
205 - Plant Management Systems;

Subject Of Investigation
1710 - Upland cotton;

Field Of Science
1020 - Physiology;
Goals / Objectives
The overarching goal of the currently proposed research is to define the contributions of production environment and genotype to fiber yield, seed component yields, and seedling vigor and crop performance in subsequent growing seasons.Specific objectives aimed at meeting this goal are as follows:Objective 1: Characterize fiber yields, seed characteristics, and seed oil and protein yield in response to water availability and nitrogen application rate. The research team will quantify fiber yields, seed characteristics, and seed oil and protein yield for cotton grown under two different irrigation treatments and three different nitrogen application rates in small-plot research trials conducted at an irrigation research facility in southern Georgia. Other than seed costs, water and nitrogen represent the two most important and costliest inputs for growers. The findings from this work will provide foundational information on how these key inputs alter not only fiber yields but also seed oil and protein yields, thereby improving the overall value of the crop without penalizing fiber yields.Objective 2: Define genotypic and environmental contributions to fiber, oil, and protein yields and provide quantitative functional relationships between the aforementioned yields using data obtained from large-scale, on-farm cotton variety trials. The team will utilize one of the most extensive on-farm cotton variety trial programs in the country, with approximately 12 of the top cotton varieties for Georgia evaluated in more than 20 yield environments across the state. Seedcotton yield will be evaluated in the field; samples will be ginned at the University of Georgia MicroGin to obtain an estimate of lint yield, and seed samples will be collected from each of these trials and analyzed for oil and protein yield. This will be the first study to utilize real-world, on-farm variety trials to define genotypic and environmental contributions to fiber, oil, and protein yield in production fields. The functional relationships developed from this objective will define lint yield ranges at which oil yields can be maximized and vice versa. Objective 3: Identify fiber and seed component yields associated with production of high quality seed that produce vigorous early season growth in cotton. Seed samples collected while addressing Objectives 1 and 2 and representing a broad range of fiber yields, oil yields and seed characteristics (seed mass, oil, and protein content) will be grown under field conditions, and seedling vigor will be assessed by evaluating stand establishment rates and multiple indicators of plant and whole-canopy growth throughout the season. Additionally, yield responses (oil, protein, and fiber) will be assessed to determine when differences in early-season vigor translate into differences in crop productivity.
Project Methods
For objective 1, a two-year field experiment will be conducted near Camilla, Georgia, where there will be two irrigation treatments (Well-Watered and Dryland) and three nitrogen application rates (0, 135, and 202 kg per hectare). At agronomic maturity for the latest maturing treatment, harvest aids will be applied to facilitate defoliation and promote boll opening. All seedcotton from the center two rows of each plot will be mechanically harvested and seedcotton weight will be determined in the field. The seedcotton samples for each plot will then be transported to the University of Georgia Micro-Gin to separate fiber from seed. From the seedcotton weights and gin turnouts for each plot, lint yield will be estimated. Additionally, cotton seed samples will be collected and weighed after each sample is ginned to estimate seed yield. Seed characteristics will also be assessed by quantifying seed weight and seed oil and protein content. Oil and protein yield will be extrapolated from the seed yields determined previously and the oil and protein concentrations of seed samples. Regarding data analysis and interpretation, statistical analysis of the effects of irrigation treatment and N rate on fiber yield, seed product yield (oil and protein), and seed characteristics (seed index, % oil, and % protein) will be conducted using a mixed-effects analysis of variance. Specifically, replicates, whole plots, and subplots are treated as random effects; irrigation treatment, N rate, and their interactions are treated as fixed effects.For objective 2, large-scale on-farm assessments of cotton fiber, seed, oil, and protein yields will be assessed in numerous production environments throughout the state of Georgia. Multiple cotton cultivars marketed for production in Georgia will be grown in large-plot on-farm research trials at numerous locations throughout the state. At crop maturity, harvest aids will be applied and commercially-available spindle pickers will be utilized to mechanically harvest each plot. Seedcotton weights for each plot will be determined on-site using a mobile load cell scale system in the field. A 9 kg sample of one replicate plot for each cultivar will be transported to the University of Georgia Micro Gin in Tifton, Georgia to obtain gin turnout for each genotype x location and calculate a lint yield for each plot harvested. During the ginning process, seed samples will be also be collected to estimate seed yield, seed index, and seed oil and protein yield concentration as described previously for objective 1. This will allow for the estimation of oil and protein yields. Data analysis and interpretation will first involve assessments of the effects of cultivar and production environment on lint, seed, oil, and protein yields. To accomplish this, a mixed-effects analysis of variance will be conducted using only the common cultivars present in on-farm trials across both growing seasons, and each location x year combination will be treated as a unique environment. Additionally, the contributions of cultivar, environment, and their interaction to total variability in lint, seed, oil, and protein yield will be assessed as a percentage of model sum of squares. This will enable us to identify genotype or environment as the dominant driver of seed, oil, and protein yields in Georgia. Finally, regression analysis will be utilized across all yield environments for each cultivar to develop quantitative relationships between fiber, seed, oil, and protein yields. This will allow us to identify environments in which seed component yields (preferably oil) can be maximized without penalizing fiber yields.For Objective 3, two separate small-plot field assessments (one for seeds from objective 1 and one for a subset of seeds from objective 2) of stand establishment, early-season plant growth, seasonal trends in crop phenology and physiology, and end-of season lint, seed, oil, and protein yield will be performed. Seeds will be delinted, treated, and planted in a randomized complete block design with four replications in small plot field trials in Tifton, GA. In both of the aforementioned small-plot experiments, stand establishment rates will be assessed by measuring plant density at 3, 5, 7, 14, and 21 days after planting (DAP) for the center two rows of each plot along with daily maximum and minimum air temperature. These data will be used to estimate growing degree day requirements to reach 50% emergence (GDD50). For plant growth and canopy development assessments, plant height and the number of mainstem leaf nodes will be assessed beginning at 21 days after planting and continuing on a bi-weekly basis until new vegetative growth ceases. Concurrent with plant height and node measurements, the fraction of light intercepted by the canopy will be calculated. From these data, leaf area index can be calculated for each plot using previously published light extinction coefficients for cotton. From the aforementioned data collection, rates of growth during the linear growth phase of development will be an indicator of vigor. Additionally, critical leaf area index is the leaf area index (LAI) at which 95% light interception by the canopy occurs and at which maximum crop growth rate is achieved. By measuring radiation interception by the canopy, we will be able to identify differences in time to reach critical LAI between the different seed sources used in each experiment. At agronomic maturity and after applying harvest aids, seedcotton, seed, oil, and protein yields will be assessed as described for previous objectives. Data analysis and interpretation will differ between the two small plot experiments. For the first experiment, a mixed-effects analysis of variance will be used to determine how these growth and yield-driving factors influence stand establishment, plant growth, and yields of the subsequently planted crop. The second experiment [on-farm variety trial seed] will answer the question "To what extent does on-farm variation in seed characteristics (mass, seed composition) affect stand establishment, growth, and yield of the subsequent crop?" To address this, multi-variate correlation analysis will first be used to test for associations between seed traits, growth indices, and fiber and seed component yields. Thereafter, regression functions will be utilized to define thresholds for important seed traits that are indicative of reductions in plant growth or yield of the subsequent crop.

Progress 04/15/24 to 04/14/25

Outputs
Target Audience:Work completed during the second year of the project was targeted for delivery to commercial planting seed suppliers, cottongrowers, cotton research scientists and extension specialists and stakeholder groups such as members of the state Georgia Cotton Commission and Cotton Incorporated. Research conducted during the second year of the project was disseminated through presentations at the Beltwide Cotton Conferences, a seed research summit hosted by Cotton Incorporated, the Crop Science Society of America Annual Meeting, and the Georgia Cotton Conferences. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has resulted in the mentoring of one PhD student. The student has received training in conducting applied crop physiology research under field conditions, training in data analysis and interpretation, and she has had opportunities for professional development through attendance and participation in a professional scientific conference. How have the results been disseminated to communities of interest?Research findings have been disseminated through two original research presentations at the Beltwide Cotton Conferences and the Crop Science Society of America Annual meeting,a presentation at a cotton seed research summit hosted byCotton Incorporated, two county extension agent trainings, and a presentation at the Georgia Cotton Conferences. What do you plan to do during the next reporting period to accomplish the goals?Objective 1. Submit manuscript to Crop Science for data obtained during2022 and 2023 growing seasons. Objective 2: Complete data analysis and submit manuscript addressing the contribution of production environment and cultivar on seed traits and seed component yields in cotton. Objective 3: a. Analyze data and prepare manuscript focused on the effects of water and nitrogen management in one season on stand establishment and yield the following season. b. Conduct final year of field experiments addressing the effect of on-farm variation in seed traits on stand establishment and productivity of the subsequently planted crop.

Impacts
What was accomplished under these goals? The overarching goal of the currently proposed research is to define the contributions of production environment and genotype to fiber yield, seed component yields, and seedling vigor and crop performance in subsequent growing seasons. Addressing this goal will identify the factors that most influence seed and seed component yields to maximize the total crop value for the producer (fiber and seed) while also ensuring that seed characteristics are within limits the ensure successful stand establishment for the subsequent crop. Addressing the objectives of the current project will provide invaluable information for researchers, cotton growers, commercial planting seed suppliers and purchasers of cotton seed/seed products. Objective 1. Major activities completed, Data Collected, and Summary: Data from the two-year field study that ended in 2023 and addressed the effect of irrigation and nitrogen on lint yield, seed yield, seed mass, and seed oil and protein content at C.M. Stripling Irrigation Research Park in Camilla, GA have been analyzed and a manuscript has been prepared from this work. Fiber, seed and oil yields were limited by drought in the second year of the project, but protein yields were not affected by drought due to the increase in seed protein percentage observed. Fiber, seed, oil, and proteinyields were limited by low N conditions in both years of the study, but increasing N application rates above current recommendations for fiber yields did not lead to increases in any of the aforementioned yields.We observed significant interactions between N and Irrigation for seed oil and protein content during the second year of the project which was characterized by yield limiting drought conditions. Specifically, drought led to successive increases in seed protein content and declines in oil content as N rates increased. However, when a water-balance based irrigation scheduling strategy was employed,the trend of increasing protein and decreasing oil content was not observed. Objective 2. Major activities completed, Data Collected, and Summary: The team collected seedcotton samples from the University of Georgia on-farm cotton variety trial during the second year of the project (2024 season). Samples were collected throughout the fall of 2024 and the winter of 2025 as they were harvested from producer fields and brought to the University of Georgia MicroGin for processing. More than 20 on-farm locations were included in data collection efforts and there were 10 different cultivars at each site. As samples for each trial came in, seedcotton samples were ginned to determined the fraction of seedcotton mass accounted for by seed and fiber. Thereafter, seed mass was determined for 100 seeds from each sample, and seed samples were transferred to the cotton physiology lab for oil and protein analysis. An analysis of the two years of data iscurrently ongoing. Objective 3. Major activities completed, Data Collected, and Summary: Seed were obtained while addressing objective 1 above following the 2023 field season, and that seed was delinted and treated prior to the 2024 field season. An experiment was conducted at a field site near Tifton, GA in 2024 to evaluate the effects of water availability and nitrogen application rate on stand establishment, canopy development throughout the growing season, and yield. There was a significant interaction between water and nitrogen application rate for final plant stand, where stand establishment was highest for seeds obtained from plants grown under either low nitrogen or irrigated conditions (stand trends followed percent oil trends observed in objective 1). Data on canopy growth trends and yield differences resulting from variations in stand establishment and/or seedling vigor are currently being analyzed as a part of manuscript preparation. As noted elsewhere in this report, seed obtained from the on-farm trial (Objective 2) were collected during the 2023 season. From these collected seed, a subset of three different cultivars and four different production environments were chosen that represented abroad range of seed traits. A randomized complete block trial was conducted during the 2024 seasonthat focused on stand establishment, canopy development and yield trends. Seed from the 2024 on-farm trial have also been selected for subsequent seedling vigor research during the 2025 season. These data will be essential in determining the extent to which production environment and cultivar influence stand establishment and productivity of the subsequently planted crop. Our efforts during the reporting period are resulting in the development of a foundational dataset on the extent to whichmanagement practices influence seed traits and the yield of important seed components such as oil and protein in cotton. Additionally, the work completed in year 2of the project has expanded our knowledge of the extent to which management practices in one growing season influence stand establishement and yield of the subsequently planted crop.

Publications


    Progress 04/15/23 to 04/14/24

    Outputs
    Target Audience:Work completed during the first year of the project was targeted for delivery to commercial planting seed suppliers, cotton growers, cotton research scientists and extension specialists and stakeholder groups such as members of the state Cotton Commission and Cotton Incorporated. Research conducted during the first year of the project was disseminated through presentationat the Beltwide Cotton Conferences and a concurrent seed research meeting hosted by Cotton Incorporated. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has resultedin the mentoring of one PhD student. The student has received trainingin conducting applied crop physiology research under field conditions,training in data analysis and interpretation, and she has had opportunities for professional development through attendance and participation in a professional scientific conference. How have the results been disseminated to communities of interest?Since this is the first year of the project, research findings have only been disseminated through an original research presentation at the Beltwide Cotton Conferences in Dallas, TX and through a concurrent seed research meeting hosted by Cotton Incorporated. What do you plan to do during the next reporting period to accomplish the goals?Objective 1 a. Analysis of existing data obtained during the 2022 and 2023 growing seasons will be performed during the second year of the project. b. Graduate student and PI will work to prepare a manuscript addressing the impacts of water and nitrogen management on seed, oil, and protein yields. Objective 2: a. Seed samples collected from on-farm trials during the 2023 season will be analyzed for seed oil and protein. b. Seed samples from the 2024 season will be collected from samples ginned in the on-farm variety trial and analyzed for seed size, oil, and protein content to determine the extent to which seed traits and seed component yields are driven by genotype, management and environment. Objective 3: a. Seed samples collected while addressing objective 1 will be delinted and treated for field evaluation of stand establishment, canopy development, and yield. b. Analysis of seed characteristics from on-farm variety trials will be completed and seeds will be delinted and treated for subsequent field evaluation of stand establishment, canopy growth, and yield.

    Impacts
    What was accomplished under these goals? The overarching goal of the currently proposed research is to define the contributions of production environment and genotype to fiber yield, seed component yields, and seedling vigor and crop performance in subsequent growing seasons. Addressing this goal will identify the factors that most influence seed and seed component yields to maximize the total crop value for the producer (fiber and seed) while also ensuring that seed characteristics are within limits the ensure successful stand establishment for the subsequent crop. Addressing the objectives of the current project will provide invaluable information for researchers, cotton growers, commercial planting seed suppliers and purchasers of cotton seed/seed products. Objective 1. Major activities completed, Data Collected, and Summary: The second of a two year field study was completed during the 2023 season that evaluated the effect of irrigation and nitrogen on lint yield, seed yield, seed mass, and seed oil and protein content at C.M. Stripling Irrigation Research Park in Camilla, GA. A well-adapted cultivar for the region was grown under irrigated or dryland conditions during the growing season, and within each irrigation treatment, three different nitrogen application rates were utilized. At crop maturity, seedcotton samples from the trial were ginned at the University of Georgia MicroGin over the winter of 2023/2024. Once ginned, seed mass data were obtained for 100 seed per sample, and seed were very recently analyzed for seed oil and protein content. In subsequent phases of the project, these data will be analyzed to determine how these major management practices or their interactions influence lint, seed, oil, and protein yield. Objective 2. Major activities completed, Data Collected, and Summary: The team collected seedcotton samples from the University of Georgia on-farm cotton variety trial during the 2023 season. Samples were collected throughout the fall of 2023 and the winter of 2024 as they were harvested from producer fields and brought to the University of Georgia MicroGin for processing. More than 20 on-farm locations were included in data collection efforts and there were 10 different cultivars at each site. As samples for each trial came in, seedcotton samples were ginned to determined the fraction of seedcotton mass accounted for by seed and fiber. Thereafter, seed mass was determined for 100 seeds from each sample, and seed samples were transferred to the cotton physiology lab for oil and protein analysis. This analysis is currently ongoing. Objective 3. Major activities completed, Data Collected, and Summary: Seed were obtained while addressing objective 1 above following the 2022 field season, and that seed was delinted and treated prior to the 2023 field season. An experiment was conducted at a field site near Tifton, GA in 2023 to evaluate the effects of water availability and nitrogen application rate on stand establishment, canopy development throughout the growing season, and yield. There was a significant interaction between water and nitrogen application rate for final plant stand, where stand establishment was highest for seeds obtained from plants grown under low nitrogen availability and irrigated conditions. Seedcotton yields, lint yields, and seed yields were all significantly affected by the irrigation and or nitrogen regimes plants were grown in during the preceding season. Yield trends were strongly associated with final plant stand and with sunlight captured by the crop canopy during the 2023 season. Seed oil and protein yields will be reported once seed from this experiment have been analyzed for seed oil and protein content. As noted elsewhere in this report, seed obtained from the on-farm trial (Objective 2) were collected during the 2023 season and are presently being analyzed for oil and protein content. Once these data are available, seed with a broad range of seed traits will be evaluated for stand establishment, canopy development and yield trends during the 2024 growing season. These data will be essential in determining the extent to which production environment and cultivar influence stand establishment and productivity of the subsequently planted crop. Our efforts during the reporting period are resulting in the development of a foundational dataset on the extent to which management practices influence seed traits and the yield of important seed components such as oil and protein in cotton. Additionally, the work completed in year 1 of the project has expanded our knowledge of the extent to which management practices in one growing season influence stand establishement and yield of the subsequently planted crop.

    Publications