Nematode Community Assemblages on Organic and Conventional Golf Courses in Massachusetts.

Many turf managers and chemical companies are looking for alternative control products for disease management, such as biological control products or other non-synthetic products.  Management practices often affect nematode communities and many studies on short-term management shifts have documented the impacts of different pesticides and fertilizers on plant pathogenic and free-living nematodes.  However, our study uses long-term organic and conventional systems (established for at least 10 years prior to the study) to analyze how these management practices affect free-living and plant pathogenic nematodes.  Plant pathogenic nematodes are of interest due to the damage they cause on turf stands.  Although less studied, free-living nematodes also play important roles in turf health and the entire nematode community can be used to predict overall soil food web stability.  We collected soil samples in the Spring and Fall of 2013 and 2014 on an organic golf course and two conventional golf courses and determined the nematode community composition on three holes per course for all three management areas (roughs, fairways, and putting greens).  Plant pathogenic nematodes were significantly greater on conventional putting greens than organic putting greens on all sampling dates.  Bacterivore nematodes showed an opposite trend: they were greater on organic putting greens than conventional putting greens.  Nematode ecological indices indicated that the organic course was less disturbed, with more resource turnover, and a decomposition pathway dominated by fungi rather than bacteria.  The results of this study can be used to develop further tests to understand management effects on nematode communities and new nematode control alternatives.