Bacillus subtilis Fungicides & Soil Amendments (2024)

Bacillus subtilis, also known as "hay bacillus" and "grass bacillus", is a hardy species of bacteria found in soils and the gastrointestinal tract of animals like cattle, goats, deer and humans. As one of the first bacterium species to be studied extensively, it is now widely used for industrial, agricultural and fermentation processes because of its ability to tolerate extreme temperatures and low humidity. Bacillus subtilis is heavily competitive in the soil and commonly outcompetes other soil microbes making it exceptional for fungal disease control in growing media and on foliage.

Bacillus subtilis competes with other microorganisms by producing antibiotics that either kill competition or reduce their growth rate. It is reported to induce SAR (systemic acquired resistance) against bacterial pathogens, whereby the plant's defenses are triggered prior to pest incursion. Additionally, Bacillus subtilis hinders spore germination in plant pathogens and prevents pathogens from attaching to the plant. When applied to the soil, Bacillus subtilis works symbiotically with numerous beneficial bacteria to solubilize phosphorus. This makes it helpful in areas where phosphate-heavy fertilizers have traditionally been used, allowing plants to absorb what is already in the soil.