Streptomyces lydicus is a naturally occurring bacterium that is commonly found in soil. When applied to soil mixes or turf grass, the bacterium protects the plant against a range of root decay fungi such as Fusarium, Pythium, Phytophthora and other species

Streptomyces lydicus can also be applied to plant foliage to control a number of foliar fungal pathogens including Botrytis and powdery mildew. 

Streptomyces lydicus works in the four following ways:
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  • Through direct competition, Streptomyces lydicus grows a defensive barrier around the root system, or rhizosphere, thereby shielding the roots from harmful attacking fungi.
 
  • It produces a chemical similar to an antibiotic, which is toxic to the invading pathogen. This process is called antibiosis.
 
  • Additionally, it attacks and feeds on the harmful pathogen. The biofungicide has to be in the rhizosphere either before or at the same time as the pathogen. 
 
  • Lastly, introducing Streptomyces lydicus kick starts the plant’s own immune defense mechanisms, enabling it to successfully fight off the invading harmful pathogen.​