Aaron Hathaway, Plant, Soil, & Microbial Sciences, Michigan State University, East Lansing, MI, Thomas A Nikolai, Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI and Kevin W. Frank, Plant, Soil & Microbial Sciences, Michigan State University, East Lansing, MI
Although golf course roughs receive few inputs relative to greens, tees, and fairways, they can comprise 60% or more of the total area on a golf course. In an effort to further reduce inputs in roughs, many have opted to eliminate mowing roughs during the growing season. These roughs have been termed secondary or naturalized roughs. While these areas quickly and successfully reduce inputs, playability is often reduced, making both finding and hitting a golf ball difficult, and reduce overall aesthetic value if weeds that were once controlled by mowing take over. The objective of this trial was to evaluate the effects of differing turf species and differing herbicide programs in these vast secondary roughs for maximized aesthetic value while also keeping them relatively playable or thin. The trial area was seeded with two different fescue mixes, a range mix that included six grass species and clover, and Kentucky bluegrass that was not reestablished but left in place. Eight herbicide programs, including preemergecnce and postemergence herbicides, were applied in the spring and fall of 2015 and 2016. The entire trial area is mowed once in the fall of each year and no fertility or irrigation has been added. Weed control, playability, inflorescence, and quality were evaluated. Herbicide programs that included sethoxydim, a postemergence grass herbicide that is safe on fescues, provided more playable secondary roughs in both years. However, these same programs reduced overall inflorescence in the roughs later in each year. Herbicide programs that included triclopyr and clopyralid, regardless of a fall or spring application timing, provided the best control of dandelion relative to programs that included 2,4-D, MCPP, and dicamba. The range mix that included many grass species had the lowest overall quality until the summer of 2016, after certain herbicide programs had effectively removed some of the grass species and the clover.