Broadleaf weeds

The weeds from broadleaf often grow alongside our lawns, especially in situations of low fertility or water stress. Broadleaf weeds are dicotyledonous, as opposed to narrow-leaved monocotyledonous weeds. Another very distinguishing feature is the presence of flowers, which is a common feature of broadleaf weeds.

The control of these weeds on golf courses has traditionally been carried out with herbicides of the phenoxyacetic family (dicamba type). All are selective and systemic. In addition, they generally require mixtures of different herbicides for optimum effectiveness, so mixtures of 2,4-D; MCPP and dicamba or individual formulations of MCPP can be used.

There are options other than the Phenoxyacetic family for the weed controlsuch as Clopyralid and Triclopyr (pyridyloxyacetic acid derivatives) have the greatest herbicidal potential. Sulphonylureas such as Chlorsulfuron and Metsulfuron are also of interest for broadleaf control in bermudagrass.

Applications of these agents should be spaced 10 to 14 days apart, always on vigorously growing, unstressed turf.

Clover (Trifolium repens), caryophyllaceae or sago are broadleaf weeds that are controlled in agrostis by MCPP, although application in summer causes yellowing of the agrostis. This component is not very effective on other broadleaf weeds.

A well-known product is based on a mixture of 2,4-D; MCPP and dicamba, for the vast majority of broadleaf weeds, although for use on agrostis it is necessary to use those formulated with very low doses of 2,4-D, as it is very phytotoxic for agrostis. 

The mixture of Clopyralid and Triclopyr does have a good effect on agrostis fairways, not on greens or tees. Quinclorac is very effective on white clover and other broadleaves in agrostis fairways, although again yellowing may occur and control tests and doses should be carried out prior to widespread use.

Below is a table with herbicides for broadleaf control in the various turfgrass species.

Herbicide Rye grass...Fescue...Poa pratensis...Bermuda.......Zoysia

2,4-D..................I......................S......................S....................S........................S....................S

MCPP.................S.....................S.....................S....................S....................S........................S....................S

Dicamba.............I......................S....................S........................S...................S

Tryc+Clop..........S......................S......................S....................S........................I....................S

Metsulfuron......NR...................NR.................NR....................S....................S

Chlorosulfuron......NR...................NR.................S.......................S.....................I

Table legend:

S=safe at recommended dose; I=intermediate safety, low-dose use; NR=not recommended.

Source: L.B. McCarty, Best Golf Course Management Practices 2001.

Tiloom recommends that you strictly follow the chemical and phytosanitary application directives in force in your country.

We invite you to comment on any experiences with broadleaf weeds in your field, and share them with the greenkeepedia community.