598822 Disclosed is a formulation effective for preventing, suppressing, treating or controlling bacterial or fungal mediated disease or decay in plants, including their fruits and/or harvestable parts; said formulation comprising an antagonistic microorganism and a booster composition, wherein said booster composition comprises: a) about 3 parts Kaolin clay; b) about 1 part yeast extract; c) about 1 part Yucca plant extract; and d) about 1 part calcium-source material, wherein the formulation does not comprise a microbe mixture comprising a mixture of beneficial bacteria including the group consisting of Bacillus subtilis, Bacillus licheniformis, Bacillus azotoformans, Bacillus megaterium, Bacillus coagulans, Bacillus pumilis, Bacillus thuringiensis, Bacillus sterotermophilis, Paenbacillus polymyxa, Paenbacillus durum, Azotobactor chroococcum, Pseudomonas aureofaceans, and Pseudomonas fluorescens. Further disclosed is a method for improving the ability of an antagonistic microorganism to prevent, suppress, treat or control bacterial or fungal mediated disease or decay in plants, including their fruits and/ or harvestable parts, the method comprising contacting a plant with a formulation as described above.