Assessing Fiber Quality Variability Among Modern Cotton Cultivars and Integrating it into the GOSSYM-based Fiber Quality Simulation Model

Background A fiber quality module developed in 2023 and integrated into the process-based mechanistic cotton crop growth and development model, GOSSYM is the first of its kind. In this fiber quality module, the functional relationships between fiber quality and the major factors influencing it (temperature, water, and nutrient status) are established based on experiments spanned four years conducted in the sunlit Soil Plant Atmospheric Research chambers. All these experiments were conducted only on the Texas Marker-1 cotton variety. Therefore, there is a possibility that the functional equations will be more aligned with this specific cultivar. Consequently, it's essential to assess how the model performs for other cotton cultivars and address any variability that arises. In this study, data from experiments conducted on 40 major cultivars currently grown in the USA, including the Texas Marker-1 variety, under the same environmental and management conditions is used to analyze the variability in fiber quality among the varieties. The measured fiber quality is then compared with the GOSSYM model-simulated fiber quality. Based on the relative variation between measured and simulated fiber quality, cultivar-dependent parameters were developed for the fiber quality model. Results Based on the relative variation between measured and simulated fiber quality, cultivar-dependent parameters were developed for the fiber quality model. The GOSSYM model, after incorporating the developed cultivar-dependent parameters, simulated the fiber quality (fiber length, strength, micronaire, and uniformity) with an average Pearson correlation coefficient value of 0.84 and index of agreement of 0.88. Conclusions This study aims to analyze the fiber quality variability among modern cotton cultivars and establish the cultivar-dependent parameters for cotton fiber quality simulation in the GOSSYM model. The parameter estimation methodology adopted and the estimated cultivar-specific parameters improved the simulation capabilities of the model. The model with cultivar-specific parameters for fiber quality will be helpful for model users, requiring less calibration effort and providing more accurate quality simulations.