Kodiak(R) - a successful biological-control product for suppression of soil-borne plant pathogens of cotton

Cotton (Gossypium spp) has been the first large-scale, agronomic crop in the United States treated with a biological-control agent (BCA) for suppression of seedling diseases and long-term chronic diseases of the rhizosphere. The vast majority of cotton seed planted in the United States is now treated with Bacillus subtilis strain GB03, registered as Kodiak(R) (Gustafson, Inc, Piano, TX, USA), Responses are typically a mixture of growth promotion (increased root mass) and disease suppression (Rhizoctonia and Fusarium spp), Strain GB03 shows exceptional rhizosphere competence, colonizing the rhizosphere of monocots and dicots, Though the initial success of strain GB03 has been observed in the production of cotton, other crops have shown positive yield responses following bacterization. Since B, subtilis is a spore-forming organism, it is extremely tolerant of environmental stresses, including seed-treatment pesticides, soil and seed pH, cultivar effects, edaphic factors and long-term storage, More importantly, it is readily produced with current fermentation technology, Other BCAs, such as Pseudomonas spp, do not readily adapt to large-scale production methods, and stability is a limiting factor, In order to be successful, scale-up production must provide a product with efficacy equivalent to the laboratory model, A better understanding of how fermentation and other production processes affect the efficacy and rhizosphere competence of biocontrol organisms is now required by the industry, Processes have to be carefully optimized for both maximum production and maximum efficacy, A strong collaboration and understanding between the agricultural industry and industrial microbiologists are required to continue the advance of new biologicals such as Kodiak(R).