Controlling weeds in fine fescue turf
By Dean Mosdell, technical services manager for Syngenta
The use of fine fescue turf types has increased over the last several years as some 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 these areas because of their slower growth habits, aesthetic appeal and tolerance of drought and low light intensities.
However, grass weeds can become problematic in fine fescue areas. Annual grasses can be effectively controlled with pre-emergence 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.
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 relatively fast-acting systemic herbicide, in that growth of sensitive plants will slow within seven days of application. However, 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 will selectively remove grass weeds such as bentgrass, orchardgrass, bermudagrass and ryegrass, among others, from fine fescue turf.
Although it may be convenient to tank-mix Fusilade II 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.
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.
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