Author ORCID Identifier:
Date of Graduation
8-2025
Document Type
Thesis
Degree Name
Master of Science in Crop, Soil & Environmental Sciences (MS)
Degree Level
Graduate
Department
Crop, Soil & Environmental Sciences
Advisor/Mentor
Drescher, Gerson
Committee Member
Bourland, Fred
Second Committee Member
Slaton, Nathan
Third Committee Member
Roberts, Trenton
Keywords
Cotton; Plant nutrition; Potassium
Abstract
Potassium (K) deficiency is a common yield-limiting factor in cotton (Gossypium hirsu tum L.) production across the U.S. Cotton Belt. Adequate fertilizer-K management is paramount to ensure optimum plant growth and development, minimizing yield losses. Currently, fertilizer K recommendations for cotton in Arkansas are derived from expected yield responses of other crops, with no calibrated fertilizer-K rates or critical tissue-K concentrations defined to maxim ize crop yield. Our research objectives were i) to investigate cotton yield response and fiber qual ity to K fertilization on soils with different K availability; ii) to correlate relative yield with tis sue-K concentrations at individual growth stages to establish critical tissue-K concentrations; iii) to define which tissue (leaf or petiole) is more sensitive to diagnose K nutritional status, and iv) to improve the cotton fertilizer-K correlation and calibration database. Ten fertilizer-K rate (0 to 187 kg K ha-1) trials were conducted on silt loam soils with soil-test K ranging from Very Low to Optimum during the 2023 and 2024 growing seasons. Cotton was planted on raised beds and fur row-irrigated. Leaf and petiole samples were collected at first square and at weekly intervals throughout reproductive growth to quantify the tissue-K concentration. At maturity, cotton was harvested to measure lint yield, and subsamples were collected to evaluate cotton lint turnout and fiber quality. Cotton lint yield was positively affected by K fertilization (P ≤ 0.10) on soils with soil-test K ≤ 90 mg K kg-1. At responsive sites, cotton yield was maximized with applications of 56 kg K ha-1 in long-term trials and 75 or 112 kg K ha-1 in single-site-year trials, with yield in creases of 53, 47, and 70%, compared to the no-K control, respectively. These results suggest that current fertilizer-K recommendations for cotton are adequate. Lint turnout and fiber quality were affected by K availability. Lint turnout was 2.4% greater across cultivars in relation to the control, and fiber elongation, uniformity, strength, and micronaire increased by 0.35%, 0.67%, 1.84 g tex-1, and 0.50 with K fertilization. Relative cotton yield was positively related to leaf- and petiole-K concentrations, with petioles showing greater R2 values (up to 0.65 during peak flow ering). The critical leaf- and petiole-K concentrations to maximize cotton yield were 10.3 and 47.3 g K kg-1 at the first flower growth stage, respectively, and decreased throughout the growing season, being 7.15 and 20.3 g K kg-1 during peak flowering and 5.14 and 7.5 g K kg-1 during boll fill, respectively. These findings emphasize the importance of adequate K management to max imize both cotton yield potential and fiber quality, as well as the need for growth-stage-specific tissue-K concentrations for optimal plant nutritional status diagnosis.
Citation
Ramos do Prado, M. (2025). Cotton Yield and Tissue-Potassium Response to Potassium Fertilization. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/5929
