Controlling weeds in fine fescue naturalized areas, especially undesirable grasses, is an ongoing battle at many golf courses. Fluazifop (Fusilade II) and sethoxydim (Segment) are often used, but these herbicides do not offer control of every grassy weed. Fortunately, the recently enhanced pinoxaden (Manuscript) label now includes use on select cool-season species. This may be the addition you’ve been looking for to manage grassy weeds in fine fescue areas.
During a recent USGA Course Consulting Service visit, I observed pinoxaden being tested to control an older variety of tall fescue because the coarse texture and bunch-type growth habit made it an undesirable grass in naturalized fine fescue areas. So far, the results are promising, but like controlling other weeds in fine fescue areas, it is likely that applications will need to be made every year for continued suppression. Similar to fluazifop and sethoxydim, pinoxaden should not be mixed with phenoxy herbicides for broadleaf weeds control or ALS-inhibiting herbicides for sedge control. These products can be antagonistic and reduce pinoxaden’s effectiveness for grassy weed control in fine fescue naturalized areas.
Any time you’re thinking about using a new herbicide – particularly to control a cool-season grass growing in another cool-season grass – it is a sound decision to test it in a few small areas before making large-acreage applications. Remember, the label is the law – so be sure to follow the recommended rates, intervals and other instructions. If managing fine fescue naturalized areas is an ongoing challenge at your course, reach out to your regional USGA agronomist for assistance on ways to improve aesthetics and playability.
Central Region Agronomists:
Zach Nicoludis, regional director – email@example.com
Paul Jacobs, agronomist – firstname.lastname@example.org
Information on the USGA’s Course Consulting Service
Contact the Green Section Staff