Overview: Dr. Gwathmey specializes in the adaptation, ecology, and management of field crops.  He leads a research project on cotton physiology in West Tennessee.  This project conducts research on the environmental physiology and agronomy of cotton to help improve the efficiency, profitability, and sustainability of cotton production in Tennessee. Project Objectives: Biomass and carbohydrate partitioning: to improve our understanding of the partitioning of starch reserves and soluble sugars in plant tissue relative to allocation of plant biomass; Nitrogen and potassium nutrition: to improve the nitrogen and potassium fertilization of cotton under Tennessee field conditions; Planting and harvest systems: to evaluate seeding rates, narrow row spacings, and planting patterns for production of spindle-picked cotton under irrigated and non-irrigated conditions; Crop condition and maturity: to evaluate the use of remotely sensed data on crop condition to monitor cotton crop maturity; and Fiber Quality: to identify environmental causes of price discounts incurred by cotton producers due to fiber quality. Project Impacts: Examples of recently reported results of the cotton physiology project include: Nitrogen and potassium nutrition: Potassium fertilizer rates currently recommended by UT Extension are inadequate for optimal yield response in early maturing, determinate cotton cultivars grown with no tillage. This finding has a direct impact on future fertilizer recommendations for no-till cotton. The economic benefit of this finding comes from improved returns on fertilizer investment. Crop condition and maturity: Cotton crop maturity can be remotely monitored with relatively inexpensive NDVI sensor technology, under conditions where nitrogen fertility is the main determinant of crop maturity. This finding is useful to regional efforts to improve a popular cotton decision-aid system. The economic benefit of this finding comes from timeliness of harvest, improving lint yield, fiber quality, and net revenue. Planting and harvest systems: Planting cotton in a 2+1 skip-row pattern can reduce planting costs to producers, with minimal loss of lint yield or earliness in row widths of 30 inches or less. This planting pattern reduces the cost of seed and other planting inputs by one-third. The economic benefit of this finding is most applicable to producers interested in planting cotton in 15- or 30-inch rows for spindle picking. Useful Links: http://westtennessee.tennessee.edu/ http://www.utextension.utk.edu/fieldCrops/cotton/index.htm