Aloe vera-mediated green-synthesized silver nanoparticles enhance physiological performance and yield in bread wheat

Green-synthesized silver nanoparticles (GS-AgNPs) have emerged as promising nano-biostimulant for improving crop productivity; however, their physiological effects under field conditions remain insufficiently understood. This study synthesized Aloe vera-mediated GS-AgNPs and characterized them using UV-Vis spectroscopy, FTIR, DLS, zeta potential, XRD, SEM, and EDX analyses. The synthesized GS-AgNPs exhibited concentration-dependent antioxidants, antifungal, antihemolytic, and phytostimulatory activities. Their agronomic potential was evaluated through foliar application at 5, 10, and 15 ppm to four bread wheat cultivars under field conditions. GS-AgNP application significantly enhanced growth, photosynthetic pigments, antioxidant defense, nitrogen metabolism, nutrient accumulation, grain nutritional quality, and yield in a cultivar-dependent manner. The 15 ppm treatment produced the greatest responses for several measured traits, although some trait-specific maxima occurred at 10 ppm. Grain yield in Borlaug-16 increased from 2.35 ± 0.11 to 6.93 ± 1.10 g plant −1 , corresponding to a 194.9% increase, while biological yield in Wafaq-23 increased by 94.25%, chlorophyll a in Zincol-16 by 216.4%, carotenoids in Wafaq-23 by 274.3%, urease activity in Zincol-16 by 169.3%, protein content in Borlaug-16 by 63.1%, and stem phosphorus in Wafaq-23 by 222.5%. Malondialdehyde, hydrogen peroxide, proline, and electrolyte leakage were reduced by 50.0%, 33.0%, 50.7%, and 26.6%, respectively. Multivariate analyses revealed strong associations among physiological, biochemical, nutritional, and yield-related traits. Collectively, low-dose Aloe vera-mediated GS-AgNPs improved wheat performance with no apparent phytotoxic effects under the tested conditions and concentrations, highlighting their potential as nano-biostimulant for wheat production.