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 th e rhizosphere. The vast majority of cotton seed planted in the United States is now treated with Bacillus subtilis strain GB03, registered a s Kodiak(R) (Gustafson, Inc, Piano, TX, USA), Responses are typically a mixture of growth promotion (increased root mass) and disease suppre ssion (Rhizoctonia and Fusarium spp), Strain GB03 shows exceptional rh izosphere competence, colonizing the rhizosphere of monocots and dicot s, 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-t reatment pesticides, soil and seed pH, cultivar effects, edaphic facto rs and long-term storage, More importantly, it is readily produced wit h current fermentation technology, Other BCAs, such as Pseudomonas spp , do not readily adapt to large-scale production methods, and stabilit y is a limiting factor, In order to be successful, scale-up production must provide a product with efficacy equivalent to the laboratory mod el, A better understanding of how fermentation and other production pr ocesses affect the efficacy and rhizosphere competence of biocontrol o rganisms is now required by the industry, Processes have to be careful ly optimized for both maximum production and maximum efficacy, A stron g collaboration and understanding between the agricultural industry an d industrial microbiologists are required to continue the advance of n ew biologicals such as Kodiak(R).