Agrobacterium radiobacter strain K84

Agrobacterium radiobacter strain K84 is a well-known biological control agent classified as a biofungicide. It is specifically utilized in agriculture to protect various nursery stocks and orchard trees from infection by soil-borne pathogens that cause significant economic damage in plant production.

The mode of action of this strain is based on competitive colonization and the production of a highly specific antibiotic compound known as agrocin 84. By occupying the infection sites on plant roots, the bacteria effectively exclude the pathogen Agrobacterium tumefaciens, which is responsible for the formation of crown gall disease.

This agent is primarily applied to fruit and nut trees, grapevines, and ornamental shrubs. Its most common use case is the dipping of bare-root nursery stock in a bacterial suspension prior to planting, ensuring that the roots are protected from the moment they are placed into potentially infested soil.

Application best practices require that the plant roots remain moist and are planted shortly after treatment to ensure that the beneficial bacteria colonize the wound surfaces effectively. Growers must avoid mixing this agent with systemic chemical fungicides or bactericides, as these chemicals can neutralize the beneficial strain K84.

Regarding safety precautions, Agrobacterium radiobacter K84 is considered non-pathogenic to humans and animals. It is a naturally occurring soil bacterium. However, standard laboratory or agricultural hygiene should be practiced, including wearing gloves during application to maintain the purity and integrity of the biological product.