This decision aid targets key weeds common to North Carolina turfgrasses. It presents information from hundreds of herbicide trials performed by Fred Yelverton, Leon Warren, Travis Gannon, Jason Hinton, and others in the Crop Science Department at North Carolina State University from 1997 until the present. We have done our best to ensure that information is presented only for labeled rates of currently-registered herbicides. However, many experimental compounds and rates were included in the herbicide trials and it is possible that a non-registered herbicide or non-labeled rate has inadvertently been included. Please check product labels carefully before applying any chemical.
The first step in effective weed management is correct identification of both turfgrass and weed. The wrong herbicide may not only do a poor job of weed control, it can also damage or kill your turfgrass. Use the Plant ID Decision Aid to identify your primary turfgrass and weed, or consult county Cooperative Extension personnel.
You will note that the words "No Data" appear after the names of some weed species in the weed dropdown list shown above. This means that no herbicide trial information is available for the selected turfgrass/weed combination. There may still be some information about cultural practices that can minimize problems with the given weed species. Each time you select a new turfgrass species, the program will search the database and determine which weed species to mark with the "No Data" label.
Once you have made your selections, the program will present information on cultural practices that can minimize or eliminate this weed as a problem. It will then search through the database of herbicide trial results. It will list, in descending order of efficacy, all those treatments that were tested against the selected weed species in the chosen turfgrass. If no trial results are found for a given turf/weed combination, then the program will search for all trials performed on the given weed species in which the turf species was not specified.
Use the "Display treatment conditions?" checkbox to display/not display turf, weed and moisture conditions at the time of treatment for each trial. This is useful information to view, but at some screen resolutions this information may scroll off the screen.
You should check the "Display pasture/right-of-way" treatment box only if you are managing either pastures or rights-of-way. These treatments cannot be used for home lawns or other turfgrass situations.
Click on the "Trt" link in the first column of the treatment table to view a graph of treatment efficacy through time, information about turf tolerance, and label precautions. In the example shown above (tall fescue/buttercup), if you click your mouse on the words "Trt: 06" in the first column directly below the words "Trial: 01-T19", the page shown below will be displayed:
If you position your mouse over the "Chemical Precautions & Warnings" icon in the top right corner of the screen, a summary of important information about turf tolerance and application precautions will appear. This page also includes the common name for each chemical and information on turf tolerance from Pest Control for Professional Turfgrass Managers.
If turf quality was rated at the same time that herbicide treatment efficacy was being evaluated, then a turf quality rating, averaged over all rating dates, will be displayed along with a description of this rating scale if you position your mouse over the "Turf Quality Index" icon:
For trials performed from 2001 until the present, the results are summarized in an annual report and these reports are available on-line. The trial ID serves as a link to this experimental report, if it is available on the TurfFiles web site. Just click the link (Trial ID) in the first column of the treatment table or on the "treatment details" page shown above. Viewing this report will allow you to determine if the differences in control between this treatment and others included in the same trial were statistically significant or not. Note that the treatment number listed directly below the Trial ID in our treatment table corresponds to the treatment number in the original report. Chemical names may have been modified in our table so that they are in agreement with product labels, or the rate may have been converted from active ingredient or acid equivalent to product application rate.
The use of brand names and any mention or listing of commercial products does not imply endorsement by North Carolina State University or discrimination against similar products not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to product labels. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical.