The use of microbial nanoparticles to stabilize antifungal activity is described. The preferred silver and gold nanoparticles are formed from various categories of microbes like bacteria, fungi and actinomycetes. The silver and gold nanoparticles synthesized from microbes, which can efficiently work as biocontrol/biofertilizer agent in field. The stabilized antagonistic activities of the microbes can be used for many other purposes with respect to the microbe selected for nanoparticle synthesis. Here the selected microbes were an indigenous organisms isolated from the tea fields that can control various diseases, individually and in combination with other microbe as biofertilizer.