Control bentgrass selectively
By Dean Mosdell, technical services manager for Syngenta
is a systemic herbicide for pre- and post-emergence control of grass and broadleaf weeds in several cool- and warm-season turf species. The active ingredient, mesotrione
, is based on a naturally occurring compound produced by the bottlebrush plant (Callistemon citrinus
). Tenacity is a HPPD (p-hydroxyphenylpyruvate-dioxygenase) inhibitor that prevents the formation of carotenoids in susceptible plant species. Without carotenoids, light energy and by-products of photosynthesis destroy chlorophyll and cell membranes, resulting in bleaching of leaves and plant death.
Certain grasses like bentgrass (Agrostis spp
.), nimblewill (Muhlenbergia spp.
) and windmillgrass (Chloris spp
.) are sensitive to Tenacity. Multiple applications can selectively remove these grasses from Kentucky bluegrass, tall fescue and perennial ryegrass. Coupled with a re-seeding program, turf areas can be converted to the desirable turf species.
It is recommended to apply Tenacity at 4-5 oz./A on a two- to three-week interval for three applications. Seeding can occur after the second application of Tenacity. Depending on location, applications of Tenacity starting in August or early September will best coincide with a re-seeding program for optimum turf conversion.
Below is a summary of Tenacity trials from across the U.S. over a number of years.
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. Trial sources: Illinois, Indiana, Iowa, South Carolina, Virginia and Washington, 2005-2007.
For more information about bentgrass control, contact your local Syngenta territory manager
or download the GreenCast®
Turf App for both Apple®
smartphones and tablets.©2019 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. GreenCast®, Tenacity® and the Syngenta logo are trademarks of a Syngenta Group Company. Apple® is a trademark of Apple Inc. Android® is a trademark of Google Inc.