Microbial strategies for the biological control of turfgrass diseases

Common approaches for implementing biological control strategies involve the use of microbial inoculants and organic amendments. The goal with these strategies is to increase populations and activities of disease-suppressive microbes associated with turfgrass plants. Microbial inoculants are used to temporarily increase soil or plant populations of disease-suppressive microbes, which require repeated applications to maintain populations at levels necessary for disease control. The use of organic amendments attempts to produce a longterm change in the soil environment whereby the activities of indigenous disease-suppressive microbes are favored. The application of some composted organic amendments not only introduces a varied and diverse microbial community into soils, but also provides a substrate for microbes already present in turfgrass soils, enhancing their population and activities. The mechanisms by which these different microbial approaches affect disease severity in turfgrasses are discussed along with a discussion of the present status and future of biological control strategies for disease control in turf.