Bacillus subtilis is a naturally occurring soil bacterium that can be used as a fungicide to protect plants from diseases caused by other fungi and bacteria. It works by colonizing the plant surface and producing antimicrobial compounds that inhibit the growth of harmful fungi. Bacillus subtilis is also beneficial for soil health, as it can help to break down organic matter and release nutrients for plants to absorb. If you're looking for a safe and effective way to protect your plants from fungal diseases, Bacillus subtilis fungicide is a great option.