The First Registered Biological Control Product For Turf Disease: Bio-Trek 22G

Diseases of golf green turfgrasses cause unsightly spots and discolorations that are undesirable and unacceptable to golf course managers and the golfing public. The development of highly effective turfgrass fungicides has revolutionized disease management of turf, especially on golf courses. However, high levels of fungicides are required. Fungicide usage on golf courses, and greens especially, is probably the most intense large-scale application per unit area in the United States. Fungicide sales are about $400 million annually in the United States, and about $100 million is spent on turf applications, with 90% of this used on golf courses. There are disadvantages to this heavy use. The most obvious of these is the frequent exposure of workers and users of managed turf areas to fungicides. In addition, there is the possibility of contamination of soil and water in and around golf courses and other areas of managed turf. This possibility of contamination is a matter of concern because much of the treated turf is in urban areas with high adjacent human populations. Wildlife may also be affected by contamination of soil or water. In addition, a large and diverse population of soil microorganisms is important to plant health. Typically, populations of fungi and bacteria (including actinomycetes) predominate in soils. Generally, the greater the diversity and activity of these soil microorganisms, the greater the overall health and fertility of the soil. However, repeated fungicide applications can severely impair microbial diversity and activity in soils of golf courses and other intensively managed turf areas. In our preliminary studies, we found one area of golf course turf in which no fungi could be detected in soil or roots. This is very unusual, and aside from golf turf ecosystems, we know of no other situation where such a drastic reduction in fungi populations has occurred. Specific undesirable consequences of this alteration of soil microflora are as follows: • It is not uncommon (nearly 100 examples can be documented) to see increases in certain diseases following fungicide application for control of other disease. This increase is due primarily to detrimental effects on nontarget organisms. • In soils where fungicides have not been applied at high rates, the diverse microbial communities present frequently provide a substantial measure of biological control. The increase in disease noted in the preceding paragraph probably is due to destruction of nontarget beneficial microorganisms. • Heavy fungicide use encourages the development of resistant populations of plant pathogens. There are numerous reports on the development of pathogen populations that are resistant to chemical fungicides, including cases where resistance was observed on golf courses. This would be expected, given the heavy fungicide applications made to greens.