Rating cool season fairway turf at Lake Tansi: Bentgrass leads the way

By Todd Mathews
Golf Course Superintendent
At Lake Tansi, we have a mixture of cool season fairway turf that includes bentgrass, Kentucky bluegrass, ryegrass, and poa annua. Ideally, we would prefer to have only 1 type of turf in our fairways. Our cool season fairways have historically had problems with heat and fungus damage. The summer turf problems have led us to begin experimenting with bermudagrass. Bermudagrass thrives in hot weather and is resistant to fungus. The bermudagrass trials are going well and we should have some good feedback by the first of next year.

In the mean time, we must maintain our cool season fairways to the best of our ability, so as to provide the best playing conditions as possible. We implemented some new fairway management strategies at the first of the year that included the use of plant growth regulators (PGR's) and some different fungicide combinations. Our fairways have been in good shape through the summer and if we can make it to September without significant damage we will be sitting pretty.

As the heat of August settled in and began inflicting stress on our turf, some cool season grasses seemed to fare better than others. Bermudagrass may be the ultimate solution to our problem, but with its 6 month dormancy we may be dealing with cool season turf for ever. As a part of the fairway turf experiments, our existing cool season turf must be figured into the equation. Here is how our cool season turf has rated thus far:

1) Creeping bentgrass- The bentgrass in our fairways has had an exceptional season so far. It has held up nicely in the heat and has been surprisingly resistant to pythium fungus. Bentgrass provides an excellent playing surface. If the fairways were 100% bentgrass, the mowing heights could be lowered and the playability would be better yet. Bentgrass is susceptible to brown patch and dollar spot, which require treatment with a fungicide. Bentgrass reacts favorably to PGR's. The PGR's have caused the bentgrass to grow lower and move laterally. Most patches of bentgrass on our fairways have significantly increased in size this summer. One of the best examples of bentgrass on our fairways is the first half of number 4.

2) Kentucky bluegrass- Our fairways were originally seeded with Kentucky bluegrass at the time of construction. Kentucky bluegrass makes a really nice fairway when the entire fairway is pure. Over time, heat and fungus damage have reduced the Kentucky bluegrass population and other grasses have taken its place. This year we have had some decent success with Kentucky bluegrass. The PGR's have been very instrumental to the improved quality we are seeing. The major problem we are experiencing with our bluegrass this summer is its high susceptibility to pythium. Out breaks of pythium fungus seems to be appearing solely on closely mown Kentucky bluegrass. Other than the fungus problems, pure Kentucky bluegrass fairways would be an excellent fit for Lake Tansi. As with bentgrass, a preventive application of pythium fungicide would greatly improve the quality of Kentucky bluegrass fairways in the latter parts of the summer.

3) Ryegrass- Ryegrass is not a very good turf for the fairways at Lake Tansi. It is not heat tolerant and it is highly susceptible to many turf diseases. Ryegrass would be more suited towards the over seeding of bermudagrass for winter color.

4) Poa annua or annual bluegrass- This species has no desirable traits and is never encouraged for use in a fairway. We are beginning to take steps at eradicating poa annua from our golf course. We fear that it will be a never ending battle as the poa annua is extremely resilient.