Should the Thatch be the Target of Microbial Studies in Turfgrass?.

Turfgrass comprises about one third of the land use in the United States and significantly contributes to our economy.  Many resources go into managing turfgrass, especially controlling fungal diseases on golf courses.  Previous studies on fungal pathogens and beneficial microbes often focus on soil communities, however the thatch of golf courses is known to have higher abundances of bacteria and fungi than the soil.  Additionally, it is believed that one of the major cool-season turfgrass pathogens, Sclerotinia homoeocarpa, overwinters in infected leaf blades, suggesting that the thatch may harbor the highest amount of this organism.  We used species-specific quantitative PCR to determine the abundance of S. homoeocarpa and one of the turf biological control organisms, Bacillus subtilis in the thatch and soil of roughs, fairways, and putting greens of one organically and two conventionally managed golf courses over two seasons.  The results of this study will have important implications for future microbe detection and monitoring efforts and for research aimed at developing sustainable management practices to reduce S. homoeocarpa and increase biocontrol organisms in the thatch.