Timing is Everything

I am a firm believer that actions taken in the Fall and Spring will indicate how successful the summer will be.  Most catastrophic turf loss can be avoided if certain steps are taken at the correct time, especially in the Spring.

I use a soil thermometer about 4 times a day beginning in March to monitor soil temperatures.  Soil temperatures, NOT air temperatures indicate what is going on with the grass plant.  The first big number to hit is 50, when root growth is initiated and a green-up should begin to occur.  If the soil has been between 50 and 55 for a prolonged period and you have seen little to no activity above ground (green grass), there are problems...either too little fertility or winter damage.

In New England soil temperatures can fluctuate greatly, increasing the difficulty of timing pesticide applications.  When soils reach 55 on a consistent basis, it is time for us to treat Bentgrass for Take-All Patch and Pythium Root Dysfunction.  If the timing is off, meaning the preventative applications are made too late or too early, you won't know until mid-July.  The causal pathogen for these two potentially devastating diseases infects in the Spring once the soil has warmed to about 55 degrees.  In the Spring, the grass plant could care less if it is infected because the growing conditions are optimal.  However, once the mid-July heat causes root dieback and the plant is under a little stress, the pathogen starts to exhibit is effects and large stands of turf will just collapse due to a poor root system.

Just this week we hit our third important temperature: 65 degrees at a depth of 2 inches for 5-6 consecutive days.  SUMMER PATCH...this one will never leave my mind.  As discussed before, our fairways are mostly Poa annua which is the grass species most susceptible to Summer Patch.  Prior to 2010 I had never seen Summer Patch on the fairways at Widow's Walk, and thus did not preventatively treat for the disease because it is very expensive to do so.  2010 started out wet; very, very wet.  After the prolonged period of sopping wet fairways at 65 to 75 degrees, Magnaporthe poae was a very happy fungus.  This pathogen had always been there, but it was never given the perfect opportunity to infect and then subsequently express its damage.  Following this wet spring was a VERY hot and VERY dry summer, which in its own right is challenging, but even more so when dealing with Poa plants with virtually NO roots.  This "perfect storm" led to wide-spread turf loss, I am talking acres of dead grass that you could literally do nothing about.  It is the first time I have ever felt embarrassed to drive around the course with my "product" out there for everyone to see.  I am fortunate to have a core of very understanding people who play and work at Widow's Walk...and the fact that the greens were unscathed and actually quite good that summer.

From the 2010 season forward, the Fairways are now preventatively treated to suppress the causal pathogen (Magnaporthe poae) from infecting Poa annua to decrease the probability of seeing Summer Patch.  Sound confusing and a little bit unsure of the methods?  That is because this disease is very difficult to control, and if you see it once the pathogen is there surviving in the soil and waiting for the perfect time to infect.  That being said, we have greatly reduced the incidence of the disease, and are very diligent in our monitoring of soil temperatures and TIMING of our fungicides.  Timing is everything, especially in the Spring when a pest-free plant is allowed to flourish and produce a solid root structure that will hopefully get it through a very stressful Summer.