COPPER OXIDE NANOPARTICLE-BASED SEED PRIMING ENHANCES GERMINATION, GROWTH, AND YIELD IN OKRA (Abelmoschus esculentus L.)

Poor seed germination and weak early vigor limit growth and yield of okra (Abelmoschus esculentus L.). Seed priming is a promising strategy for improving crop establishment, and nanoparticle-based priming may enhance nutrient delivery compared to ionic sources. In this study, copper oxide nanoparticles (CuO NPs) were green-synthesized using radish (Raphanus sativus L.) leaf extract and characterized by FTIR, FESEM–EDS, and zeta potential analysis. The CuO NPs exhibited near-spherical morphology (150–250 nm), confirmed Cu–O bonding, and moderate colloidal stability (−23.21 mV). Seed priming did not significantly affect germination percentage; however, seedling growth responses were strongly treatment dependent. CuO NP priming at 25–50 ppm significantly enhanced root length and fresh biomass, while CuSO4 treatments caused growth inhibition. Pot experiments showed that CuO NP priming significantly increased plant height, pod number, pod length, and total yield, with maximum yield recorded at 50 ppm. Strong positive correlations were observed among vegetative growth, pod traits, and yield. In conclusion, green-synthesized CuO NPs applied through seed priming were more effective than ionic copper in enhancing okra growth and productivity, highlighting their potential as a nano-enabled strategy for sustainable crop improvement.