in vitro antifungal activity of silver nanoparticles, at concentrations of 6, 8, 10, 12, 14 and 16 ppm, was studied on five phytopathogenic fungi, and a biocontrol agent. then effect of silver nanoparticle at 6 ppm (optimum concentration) was evaluated on macrophomina phaseolina in greenhouse. for in vitro experiment, the fungal isolates were grown on potato dextrose agar medium amended with si...