Part 2
Successful Bermudagrass Eradication
One of the most crucial aspects of the 2021 renovation at Olde Florida is the eradication of the existing turfgrass. If a high level of bermudagrass eradication is not achieved the results of the golf course renovation will be less than desirable.
Bermudagrass eradication is extremely challenging due in part to the plants inherent deep rhizomes. A rhizome is a horizontal, underground stem, which puts out lateral shoots and roots at multiple intervals. Rhizomes can remain dormant for long periods of time and eventually allow bermudagrass to regenerate when growing conditions are favorable.
Extensive research has been performed on bermudagrass eradication. I have based the eradication program at Olde Florida on three peer reviewed university studies, which are summarized below.
The first study was performed by B.J. Johnson, while at the University of Georgia. The results of Dr. Johnson’s research were published in 1988. The data showed that three applications of glyphosate at 2 quarts per acre were needed to achieve acceptable control. His applications were made in May, June and August.
Dr. Johnson's research also demonstrated that three glyphosate applications, which is a lower than allowable labeled rate, were much more effective than a higher, single or split application.
The second definitive study was performed by John Boyd at the University of Arkansas in 1998 and 1999 and published in 2000. Dr. Boyd's research confirmed Dr. Johnson's data from a decade earlier. The results again demonstrated that three applications of glyphosate at 2 quarts per acre, to actively growing, non-stressed bermudagrass over the entire summer were necessary to achieve 98% control.
Dr. Boyd's study also confirmed that repeat split applications were far superior to a single application of the herbicide at the maximum label rate. In fact, Dr. Boyd found that 5 months after a single application at the maximum label rate, the plot had zero percent control, as compared to 98% control on the three application plot at the reduced rate of 2 quarts per acre.
Finally, in 2001 and 2002 at the University of Florida, West Florida Research Center another study on bermudagrass eradicaton was conducted. The data from this research concluded that three applications of glyphosate tank mixed with an additional herbicide, Fusilade II, four weeks apart achieved 99% control 12 weeks after initial treatment. Dr. Bryan Unruh, Professor and Associate Center Director, University of Florida was one of the researchers in this study. I have consulted with Dr. Unruh on many aspects of the project at Olde Florida.
The timing between the herbicide applications is also a key component to the bermudagrass eradication process. Re-growth is essential since spraying “brown”, non-actively growing bermudagrass with postemergence herbicides is of no value. An important component of encouraging bermudagrass re-growth is the maintenance of adequate moisture and nutrient levels in the soil. The Olde Florida agronomy team will be providing irrigation based on the plants need, as well as supplying a food source with light frequent applications of soluble nitrogen throughout the entire eradication process.
The herbicide applications at Olde Florida are scheduled (weather permitting) for March 16, April 19 and May 21. Grassing the golf course will not begin until mid-June, which will allow for additional spot treatments (after the scheduled three complete applications) if deemed necessary.
Herbicide Application at Olde Florida Golf Club on March 16, 2021
Herbicide Application at Olde Florida Golf Club on March 16, 2021
Herbicide Application (Click here, or above to play video) at Olde Florida Golf Club on March 16, 2021
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