In mid February we started to notice some small areas on some of the putting surfaces here at Granite Bay that were thinning out and reminiscent of disease activity. Some diseases that effect golf course turf are relatively easy to identify and others not so easy. Thankfully we have many tools at our disposal to deal with the uncertainties that nature throws at us on occasion. One of those indispensable tools are diagnostic labs that provide positive diagnosis of disease and root zone conditions.
|Sample sent to Dr. Phil Colbaugh from Texas A&M.|
Proceeding pictures were provided by Dr. Colbaugh
in his diagnosis of Pythium Root Rot here at GB.
Our first suspicion was that the turf on the greens were a little hungry and needed some fertilizer. Typically we don't want to encourage unnecessary growth at any time of the year particularly in the winter as this has a direct certain disease susceptibility's, further excessive organic matter development and most importantly putting quality. That being said we knew we were a little on the "lean" side so applied an application of fertility hoping it would cure the symptom's we were observing. To be on the safe side before making this fertilizer application we took a sample of a suspicious area on a green to send to a lab for diagnostic analysis.
|A magnified root showing Pythium spores embeded in the|
It is a good thing that we did because the sample came back with a positive diagnosis for Pythium Root Rot, a pathogen that starts it's infection in roots and infects other roots below the surface. Root diseases are a lot different then foliar diseases in that by the time you see symptoms the damage is already done because roots have been effected and no regeneration or re-growth is possible from those effected plants.
|These washed roots actually represent a follow-up sample|
to make sure we have control of this stubborn disease.
The strategy after a positive diagnosis is to stop the disease pathogen from its continued spread and then do the cultural things required for regeneration. Stopping a root disease is somewhat tricky as fungicide applications have to be applied in high volumes of water to reach the root zone where the disease activity is active. Our applications after receiving a positive diagnosis on Monday 2/20/12 were made on Tuesday 2/21/12 and the following Monday 2/27/12 when we were closed.
At this time in early March we have control of the disease and are starting to see recovery. Recovery strategies include a slight increase in the height of cut on our greens mowers, stepped up fertility regimen, increased spiking to allow air exchange and now that we have achieved control we will add seed to the effected areas on our greens particularly on #1, #5 & #6. Although we have not decreased our greens rolling frequency, putting surface speed have decreased as a result of the above mentioned practices.
|Follow up root magnification showing Pythium|
currently under control.
Core aeration is scheduled for the first week in April so we are currently four weeks away. With the current weather patterns and our recovery strategy we could very well see complete recovery before aeration. The aggressive aeration program we initiated last year has paid off as these surfaces are not nearly as soft under foot as they were previously. However we still have a highly organic layer in our top 2" which definitely contributes to their susceptibility to these types of diseases. Bottom line is we need to continue our aggressive appraoch when it comes to core aeration which will go along way in creating healthy conditions that are not as susceptible to these type diseases and perform in the fast and firm manner which we all desire.