Etiolated Tiller Syndrome

In order to continue to improve the health of some of the problem greens, I have enlisted the help of many others in the agronomy field. I have reached out to diagnostic labs throughout the Midwest, universities from both coasts, and the USGA. In this search for any and all possible problems (beyond the ones my eyes and experience can identify), we may have found one possible underlying issue. The last samples tested showed signs of bacterial streaming, which is the flow of bacteria from a cut leaf blade. Following a period of isolation, the bacteria proved to be Acidovorax avenae. The presence of this bacteria has been loosely linked to Etiolated Tiller Syndrome (ETS).

This is an extremely understudied syndrome that not many people know much about. In fact, there are many out there that still cannot agree on whether ETS is a symptom or the cause of a symptom. Research on this issue continues to increase and will hopefuly shed more light on the possible effects of this syndrome. I emphasize the word "possible" because it isn't known to what extent ETS is an issue. Many believe it is simply an aesthetic issue, while others are not sure.  I believe ETS is a secondary issue brought on by high moisture content in the soils combined with the use of bio stimulants and products containing plant hormones. It just seemed too convenient that we were seeing symptoms on our greens that consistently hold more water and also have a much heavier silt layer in them.

The physical symptom of ETS is elongated leaf blades that exhibit accelerated growth rates. These leaf blades appear lime green in color because the chlorophyll is dilluted over a larger surface area. I was assured that these leaf blades are photosynthetically functional and the root samples I have pulled have all been adequate to great. Even if the plant is perfectly healthy, I do believe the elongated leaf is structurally weaker and far more prone to mechanical damage and foot traffic.

Note the lighter green turf. These symptoms appeared around the end of June.

In an effort to get ahead of any issues, we have tried to remove as much mechanical stress as possible from our management routine, as well as give some of the newly constructed areas on Gray Hawk some timeoff. We have begun push mowing the troubled greens to eliminate the stress of the riding mowers and are keeping the greens on a much more aggressive venting cycle.  A concerted effort has also been made to increase air movement in some of our pocketed green locations. Every superintendent I have spoken with was adamant about the improvement they see from air movement and the use of turf fans. This explains the tree removal that took place on #5 Gray Hawk, as well as the use of the fans around that green. We are also experimenting with a different watering technique. With this method, we flood the soil profile and then gradually dry it down until the moisture looses contact with the root system, at which point we flood it again. It seems to take about a week to complete this cycle. We hope this will provide adequate moisture without keeping the profile bogged down.

As I walked the greens the past few weeks, and my wife will attest that I have walked them alot, I really feel like they are healthy. The root systems seem dense and deep. We need to continue to keep an eye on our watering techniques and try to manage water away from the surface by pushing it down toward the root system. We also need to manage wear and tear in certain areas and allow areas of new or stressed turf to have a break every now and then.

Roots system on #5 Gray Hawk green

Use of fans and tree removal on #5 Gray Hawk green site