GREEN SYNTHESIS OF AGNPS AND THEIR EFFECTS ON SEED GERMINATION AND SEEDLING VIGOR IN <em>ACACIA</em> <em>SENEGAL</em> AND <em>ACACIA</em> <em>MELLIFERA</em>

Abstract

The biosynthesis of silver nanoparticles (AgNPs) was purposively performed and their effects on seed germination and seedling vigor in Acacia senegal and Acacia mellifera were assessed in the experiment. The structural properties of the synthesised AgNPs were characterised using powder X-ray diffraction. The average particle was size at 26.51 ± 8.72 nm using Transmission Electron Microscopy, and the sharp color change and the emergence of a characteristic peaked at 415 nm in the UV-Vis Spectrum. Fourier Transform Infrared Spectroscopy was used to detect functional groups, morphological properties, size and shape of AgNPs which were visualised using Scanning Electron Microscope. A completely randomized design was used for the experiment with four replicates and four pre-sowing treatments consisting of silver nanoparticles at different concentrations of (control, 25, 50 and 75 mg L^-1) to examine seed germination and seedling growth characteristics. AgNPs treated seeds showed a high germination rate with early growth of seedlings at concentration (75 mg L^-1) in A. mellifera (100%) and A. senegal (72.5%) at the greenhouse condition, compared to the control, which recorded (50%) and (42%) for A. mellifera and A. senegal, respectively. Additionally, the seedlings growth reached maximum shoot height of 75 cm and 60 cm with the 75 mg L^-1 AgNPs treatment, compared to 40 cm and 32 cm in the control group for A. mellifera and A. senegal, respectively. Silver nanoparticles had successfully improved seed germination and seedling growth in the two studied Acacia species.