Nematodes, the unseen assassins

One of the hardest things to understand in the crazy world of golf maintenance is all of the intricate and inter-related balances that need to occur within the soil to have the grass not only survive, but meet player's expectations.  In order to meet the expectations of what it is supposed to look like above the ground, you have to start by what it looks like below the ground.  You have to get back to your roots!  The root is the key to having a lush, think turf canopy.  So if you really boil it all down, almost everything that is done for the grass on a golf course is really done to promote root growth.

When the roots of the plant are fat, fibrous, white and extensive a superintendent sleeps pretty soundly at night.  I sleep better because I know the plant is living good.  Yet, despite best efforts sometimes, there are things out there that do their darnedest to rain on the parade.  Those thick, white roots are also perfect food for a parasitic worm that lives in the soil called a nematode.  These nematodes have a stylet (looks like a hypodermic needle) on the tip of their body that they inject into the plant roots to be able to parasitically live off of the grass plant.  Depending on the type of nematode and quantity, the damage to the root system can be very severe.

This picture illustrates how severe the damage can be if left unchecked.  It's not hard to tell which one the nematodes are munching on!

Some of you might be asking why I'm discussing nematodes at the end of December when for the past three years you have heard me talking about them in the summer.  The reason has to do with the Clubhouse putting green.  I recently did some nematode testing of the putting surfaces that were not performing well to see if in fact my hunch was right....it was.  The clubhouse putting surface has a very high nematode population in a few areas.

In this picture you can see the southeastern corner of the clubhouse putting green not looking so good.  This is one of the areas that tested positive for a very high nematode population.

The test results for that section of the green showed we have over 4 times the threshold level of Lance nematodes in the soil.  To treat the area, we had to use a product that required a 24 hour no re-entry and that is why a few weeks ago we had to close the putting green.

Here is a picture of the green a few weeks after treatment.

The area is getting a little bit better.  The ultimate answer to these pesky areas of high nematode populations is to use a product called Curfew.  Unfortunately, the process of applying the Curfew is pretty disruptive to the putting surface since it has to be injected six inches into the soil.  Therefore, we will have to wait until the summer when the rest of the course gets its annual nematode treatment.  Until then, we will do some additional spot fertilizing and watering of these troubled spots to ensure they continuing to progress towards full turf coverage.