Darren J. Davis

Like many southern golf courses planted with bermudagrass in the late 1980s and early '90s, Olde Florida Golf Club in Naples, Fla., was recently faced with a distressing situation: The turfgrass on the golf course lacked genetic purity. The presence of numerous "off-types" in the so-called bermudagrass turf had progressed from just an aesthetic distraction to a playability issue.

Olde Florida was originally planted in late 1992 with turfgrass from a Florida sod producer. The original construction specifications called for Tifdwarf bermudagrass on the putting surfaces and Tifway 419 bermudagrass on the remainder of the golf course. Unfortunately, it became painfully evident very early after the course's opening that the turfgrass that was planted lacked genetic purity.

After a few years the problem worsened. Irrefutable blame became hard to place because with each passing year it became unclear whether the off-types originated from mutation of the originally sodded turfgrass, contamination of planting stock or introduction of off-type seed or vegetative parts. However, after researching the predicament what became painfully obvious was that with the abandonment of the turfgrass certification program in the state of Florida in 1985, the planting material originating from most sod growers in Florida had severely deteriorated. In fact, until recently the names Tifway 419 or Tifdwarf meant very little to superintendents in the South, as these terms had

become the generic description for all bermudagrass sold in the state. Fortunately, the certification program has been reinstated in Florida, and other southern states have also greatly improved their certification standards, resulting in a renewed confidence in certified turfgrass.

Feeling more confident that a genetically pure turfgrass stand could be purchased in today's market, we investigated renovating our existing mixed stand of bermudagrass to a true mono-turf stand. Step one was to simply show the need and convince the powers that be at Olde Florida that the re-grassing of the golf course was a worthy investment for the future of the club.

I believe that superintendents can be their own worst critics, as we strive continually to provide our golfers with the absolute best turf conditions possible. Sometimes golfers think that we will never be truly happy. In the early years of my club I was told, year after year, that I was the only one who noticed the problem with the off-types. However, as the years passed the additional inputs we had been using to mask those problems, such as additional fertilizer, water and to a degree pesticides, no longer provided the results that today's golfer demands.

Next, we researched techniques to eliminate the existing

same level of control could be obtained in a shorter time frame and with one less spray application if the glyphosate was tank-mixed with fluazifop-P-butyl (Fusilade II).

Having completed the tedious task of killing an 8-year-old mixed stand of bermudagrass, I stress that it is very important to clearly understand the mode of action of glyphosate.

both Johnson and Boyd emphasize that in order to obtain the desired results, the turfgrass must be allowed to re-grow prior to additional applications of the chemical(s).

At Olde Florida, we decided that 96 percent control was not acceptable, especially since the price tag on our project was to exceed $1.4 million. For this reason, we decided to also apply methyl bromide fumigation to all of our tees, fairways, approaches and greens (100 acres of turfgrass). At 96 percent control from glyphosate applications, we would still have the potential for four acres of off-type bermudagrass that would survive sporadically on the golf course. Left untreated, we knew, these four acres could quickly re-contaminate the golf course.

The next decision we faced was whether to employ a general contractor. I had confidence in my staff and our ability to perform the task correctly and efficiently, so we decided not to hire a general contractor. However, depending on your particular labor situation and depth of management personnel, if you choose to employ a contractor, it is vital to have well-written specifications that leave nothing to chance. You will also need to research and become comfortable that the contractor is capable of providing the quality of work that you expect, in the allotted time.

After several months of research and planning, we were confident that we could eradicate the existing bermudagrass,

co-mingled stand of bermudagrass. After visiting many golf courses in the South that had undertaken similar renovations with varying degrees of success, I became convinced that the most critical step in the project was to eradicate the existing bermudagrass prior to planting any new turfgrass. Research on this subject was somewhat limited, but we located two published research projects that dealt with the eradication of existing bermudagrass.

The first was published in 1988 by B.J. Johnson, Ph.D., of the University of Georgia. His findings reported that 96 percent control of an existing stand of bermudagrass could be obtained if three applications of glyphosate were applied over a four-month active growing period. This research had provided the standard method for bermudagrass eradication in the industry for many years. Unfortunately, for most golf courses, this lengthy window is usually not possible, and decreasing the time frame could result in an unacceptable level of eradication.

The second report, by John Boyd, Ph.D., of the University of Arkansas, was published in the May 2000 issue of GCM. At Olde Florida we relied heavily on Boyd's findings. His study was based on Johnson's proven research, but what made Boyd's research particularly useful to us was that his findings that the

so our next step was to locate a reputable grassing company and secure the necessary bermudagrass to re-vegetate the golf course. Even with the strides made in turfgrass certification in the South, cautious legwork is necessary to ensure that what is specified is what is received. Unfortunately, all grassing companies do not have the same standards

and pride in the product they are producing and selling.

On our course in Southwest Florida, we determined that we could complete the eradication, prep work and re-grass in a seven-month window from May 10 to Dec. 10, 2000. This time frame had two advantages. First, this period is our off-season; second, the bermudagrass is most actively growing in the summer. This definitely assisted us in both the eradication and subsequent grow-in of the new turfgrass. Shortening this time frame could be disastrous, primarily because rushing the killing process will result in a poor kill and a waste of a lot of money and time when the results prove to be unacceptable.

Prior to starting a project, it is helpful to analyze other components of the golf course and determine if, during this closed period, it would be appropriate to make changes, improvements or additions. One of the first things we took

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