Vol. 9, Special Issue 12, Part R (2025)

Cotton is an economically important fibre crop whose growth and productivity are influenced by hormonal balance, nutrient uptake, and stress regulation. Chitosan-based nanoparticles have emerged as an efficient nano-biopolymer technology for enhancing plant growth due to their slow-release behavior and ability to improve nutrient absorption, hydration status, and metabolic activity. The present investigation entitled “Physiological Response of Chitosan-Based Indole Acetic Acid Nanoparticles in Cotton” was conducted during Kharif 2022-2023 at the Department of Agricultural Botany, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, to evaluate the effect of chitosan, IAA, and chitosan-based IAA nanoparticles on morphological and physiological growth attributes of cotton. The experiment comprised ten treatments with foliar sprays of auxin, chitosan, and varying concentrations of chitosan-based IAA nanoparticles. Results revealed that treatment 25 ppm auxin (T₂) recorded significantly maximum plant height, leaf area, leaf area index, and dry matter accumulation, while 75 ppm chitosan (T₃) resulted in the highest relative water content at harvest. Conversely, the lowest values for all parameters were obtained under the control (T₁). While twice-applied auxin at 25 ppm primarily enhanced morphological traits, nanoparticle treatment was more effective in improving yield and yield-attributing characters, with chitosan (75 ppm) further contributing to improved water retention and stress tolerance.