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Thousands, if not hundreds of thousands, of acres of CRP originally enrolled in tall fescue will be converted to native warm season grasses over the next few years. The new Farm Bill allowed for the re-enrollment of CRP for another 10 years, under certain conditions. Every CRP contract was assigned an Environmental Benefit Index (EBI). This was a scoring system to rank CRP offerings. Erosion control, water quality and wildlife habitat, all received equal consideration. The higher the score the more likely the contract was to be accepted. Acres originally planted to fescue were accepted if the landowner agreed to convert to native warm season grasses, which gave them a higher EBI. Now faced with the challenge of converting tall fescue to native warm season grasses, it is important that reliable, effective, economical methods of killing tall fescue be made available to landowners faced with the process of making the conversion from fescue to native grasses.
There have been a number of people experiment with different methods of killing fescue. The motivation behind most of those experimentations has been to find a cheaper way of doing it. My experience with killing fescue, however, has been not to cut any corners. The process of trying to take a short cut can come back to haunt you in the form of an incomplete fescue kill. You then have to either start all over or do additional management or herbicide applications to complete the job of killing the fescue, which takes more time and money. In my opinion it is better to spend a little more money in the beginning and get the job done right.

I no-tilled 8 acres of indiangrass and 8 acres of big bluestem into fescue sod this spring using this method and this fall have thigh to waist deep big bluestem and shin to knee deep indiangrass. This is the most phenomenal native grass planting I have ever done and that includes over 4,000 acres of plantings. There are two options for using this method. The first option, is to allow the fescue to grow the season before you want to make the conversion. It is important that there is plenty of residual matter, litter, to carry a good fire. In the spring, after the fescue has greened up, but still dry enough to burn, burn off the area. Allow 4 to 8 inches regrowth then apply the following chemical mixture. One quart Roundup Ultra, 8 to 12 ounces Plateau, 1 quart methylated seed oil (MSO) and 17 pounds of ammonium sulfate per 100 gallons of water. Use a spray rate of 20 gallons per acre. If you want complete control don't short cut on any of the ingredients.

The second option uses the same spray mix and rate but does not use burning. Hay the fescue late in the year the preceding fall. It is important that the haying be done to remove the litter and late enough in the year that there is limited regrowth. The goal is to have no more than 8 inches of growth when it is sprayed the following spring.

The second option, will most likely, not be available to use on CRP acres since hay harvest is not allowed. In some cases there may be some exceptions. Be sure to check with your local NRCS or FSA office.

You also need to be aware that Plateau is labeled for only 4 ounces on CRP. American Cyanamid is in the process of getting a label change approved by the EPA but I don't know if the change will be effective by planting time next spring. It is hoped that the change will be effective by the first of the year. I'll keep you posted.

There are a few tips you need to know about using this chemical mix. First, don't let your chemical supplier talk you out of using methylated seed oil because Roundup Ultra already has a surfactant in it. Methylated seed oil improves the effectiveness of the chemicals to improve the fescue kill. Second, don't leave out the ammonium sulfate, it too increases the effectiveness of the chemicals. Timing of your application can be important. If you spray too early, there is the potential for warm season perennials that are tolerant to Plateau and could present competition problems, haven't broken dormancy. It is therefore important that they are actively growing so the Roundup Ultra can do its job on them. Don't wait too long though, fescue treated when it is entering its reproductive stage doesn't take up the chemical as well and is harder to kill. Spray before fescue seed heads begin to develop. If it has gotten past that point, use 2 qts. of Roundup Ultra rather than one.

This tank mix gives fescue the one - two punch with some extra zing. The MSO and the ammonium sulfate provide the extra zing by increasing the uptake of the chemicals and making them more effective. The Roundup Ultra provides good burn down of growing vegetation and the Plateau provides additional killing power for the fescue as well as providing residual control. The Plateau will knock out any fescue seeds that may germinate and also control common competition problems like foxtail and crabgrass. The addition of the Plateau and the residual weed control it provides really allows the native grasses to express themselves in the first year making the phenomenal growth I described earlier possible.


These are the prices I paid in the spring of 1997. Prices may change from year to year or be different in your location.
Roundup Ultra - $12.75/qt.
Plateau - $ 1.88/oz.*
MSO - $ 3.54/qt.
Ammonium sulfate - $ .22/lb.
Custom application - $ 4.00/a
*Effective October 1, 1997 - Plateau price will be $1.96/oz.

IMPORTANT NOTE: Plateau is a growth regulation herbicide. Its method of activity is the same for all plants, however the native grasses are able to metabolize the chemical before it will kill them, as it does fescue and other labeled plants. Expect slower initial growth of native grass seedlings when compare to untreated areas. However, weed control will give the native grasses a competitive advantage resulting in late season growth that will far surpass untreated areas.


All of these methods will kill fescue, some better than others. None-the-less, once the fescue is killed there are still problems from weed competition. These will require additional management after planting to control weeds for acceptable establishment.
My former preferred method was nearly the same as the one outlined above, except for the MSO and Plateau; allow growth the year before, burn as late as possible in the spring and spray with 2 qts of Roundup and ammonium sulfate when fescue is 4 to 8 inches tall. I had tremendous results in killing fescue using that method, however the typical competition problems occurred during establishment. There are many managers who used and continue to use a split application method. For several years now this has been the most widely used method and what I refer to as the traditional method. It is very effective, but what I see as a draw back, requires two applications of Roundup, one in the fall and a follow up treatment in the spring, therefore, two application costs. This method requires mowing the fescue in the late summer to expose new growth for the fall. Spray with 1 qt of Roundup with a surfactant (Roundup Ultra) at a spray rate of 10 gallons per acre when the fescue is 8 to 10 inches tall. The spring follow up treatment is the same, 1 qt Roundup, when fescue is 8 to 10 inches tall.

Gramoxone has also been used, however results have not been as reliable. Either fall treatments or spring treatments usually require two applications. Apply 2.5 pts of gramoxone at a spray rate of 20 - 30 gallons per acre. Apply 1.5 pts as the follow up treatment. Gramoxone has also been used in a tank mix with Roundup, primarily because gramoxone shows a quick brown out, or burn down of the plants. This gives a false sense of security though since gramoxone is not as effective and resprouting will probably occur.

The old, time honored method, cropping can also be used. If no herbicides are going to be used, fall plowing is the most effective. Fall plowing exposes the roots to the forces of winter which help to kill it. Whoa!! Hold the phone, you said fall plowing? What about soil erosion? Use some common sense, don't plow through your ditches, plow on the contour and leave field borders and filter strips around drainages. But fall plowing is detrimental to wildlife. We're talking about fescue here, remember? If not plowing, spray 2 qts of Roundup in the fall or spring or split the application and no-till. Plant a crop of milo, corn or soybeans and use traditional herbicides with those crops. Be sure to check the Rotational Crop Restrictions section of the label before deciding upon which herbicide to use with your row crop to prevent any problems with chemical carryover. Be particularly cautious with the soybean herbicides.