Controlling weeds in fine fescue turf
May 16, 2023
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By Matt Giese, M.S., technical services manager for Syngenta
The use of fine fescue turf types has increased over the last decade as golf course superintendents shift out-of-play areas and secondary roughs to lower-maintenance grasses in cooler regions of the country. Fine fescues are a great fit for these areas because of their slower growth habits, aesthetic appeal and tolerance of drought and low light intensities.
Pre-emergent weed control
Grass weeds can become problematic in fine fescue areas. Annual grasses can be effectively controlled with pre-emergent herbicides like Barricade® 4FL herbicide, which is recommended at a rate of 10-24 fl. oz./A depending on location and seasonal differences. Control of perennial grasses like bermudagrass, orchardgrass, ryegrass and bentgrass, however, require a different strategy.
Post-emergent weed control
Fusilade® II herbicide is a selective post-emergent herbicide that disrupts synthesis of fatty acids in grasses, leading to inhibition of cell membranes and development of new plant tissue.
It is a systemic herbicide that slows growth within seven days of application
It may take three to four weeks for complete control of sensitive plants
Sequential applications on 28-day intervals can be made on fine fescue turf at a rate of 16 fl. oz./A
Fusilade II selectivity is based on the ability of the herbicide to bind to an enzyme that catalyzes fatty acid formation. The enzyme in dicot plant species and fine fescues is naturally resistant. Fusilade II can selectively remove grass weeds such as bentgrass, bermudagrass and ryegrass from fine fescue turf. Fusilade II also has a 2(ee) recommendation for selectively removing orchardgrass from fine fescue turf.
Recent enhancements to the Manuscript label, now include use on fine fescues. Powered by the active ingredient, pinoxaden, Manuscript has been trusted by turf managers to control persistent grassy weeds in warm-season turf species since it was first launched in 2018. Manuscript, which is a new mode of action in the same class as Fusilade II, offers an additional option for post-emergent control of foxtails, barnyardgrass, canarygrass, and paspalums that can be difficult to selectively remove from fine fescue stands. Manuscript can be complimentary to Fusilade II in a weed control program for fine fescue naturalized areas.
Although it may be convenient to tank mix Fusilade II or Manuscript with other herbicides to control dicot and sedge weeds, this class of herbicides does not mix well with phenoxy herbicides such as 2, 4-D and ALS herbicides like halosulfuron. This antagonism results in lower grass weed control. It is recommended that these sprays be separated by at least one week for optimum weed control.
In the study above, no phytotoxicity or growth regulation was observed with applications of Fusilade II. The quality of desirable turf remained the same as desirable turf in the untreated control.
Several proven Syngenta programs incorporating Fusilade II and Manuscript are available for managing weeds in fine fescue naturalized areas and can be found at GreenCastOnline.com/Programs.
To learn more about weed control in fine fescue turf, contact your local Syngenta territory manager.
Performance assessments are based upon results or analysis of public information, field observations and/or internal Syngenta evaluations. Trials reflect treatment rates commonly recommended in the marketplace.
© 2023 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties and/or may have state-specific use requirements. Please check with your local extension service to ensure registration and proper use. Syngenta supports a FIFRA Section 2(ee) recommendation for Fusilade II for orchardgrass. Please see the Section 2(ee) recommendation to confirm that the recommendation is applicable in your state. The Section 2(ee) recommendation for Fusilade II must be in the possession of the user at the time of application. Barricade®, Fusilade®, Manuscript® and the Syngenta logo are trademarks of a Syngenta Group Company. All other trademarks used herein are the property of their respective third-party owners.