Insurance Policy

I strive to describe our maintenance procedures in easily understandable analogies.  I do this for purely selfish reasons.  Its easier for me to write my blog and its easier for members reading to grasp some very technical turfgrass concepts.  One of the most difficult concepts to describe in accurate detail is the life cycle of the Annual Bluegrass Weevil(ABW). Suffice it to say it is the most difficult insect to control of cool season turfgrass.

The ABW host is the Poa annua plant.  We have varying populations of Poa annua present in our greens, tees, and fairways.  I suspect that we may have some Annual Bluegrass larvae damage in our greens.  The larvae chew on the Poa annua  roots and once the integrity of the roots are compromised the plant cannot withstand high daytime temperatures. Our preventative ABW program or "insurance policy" is full coverage on the greens.  However, if the timing of program is off by a few days this can lead to turfgrass loss.  I hypothesize that my preventative application may have been too early and did not suppress all of the ABW larvae.  Consequently we have some off color areas on our greens.

The Poa in the fairways is none too happy right now.

As you can see the dark green area is bentgrass and its healthy.  The yellow sparse area is Poa annua. Its hard not to notice that some of our fairways are predominately Poa annua. Our "insurance policy" for ABW in our fairways is the bare minimum.  The main reason for this is it is very costly to increase our policy.  I make only one application to suppress ABW larvae.  The first wave of ABW is the most destructive and if not timed right can lead to turfgrass loss.  Again, I feel my timing was off and this resulted in poor efficacy.  There are three life cycles per year of the ABW so its going to be a wild ride for the rest of the summer.

As you can see these weevils are very small and a microscope is needed to detect the first larvae instar.  As the larvae progress to the third and fourth instar they can be visually identified by inspecting the thatch/soil interface.  If visually identified in high numbers the plant will wilt and die during stressful weather conditions.

What can I do now?  I will apply a wetting agent and foliar fertilizers to the fairways to nurse back the Poa plants.  I hope we have some favorable weather days ahead as this will aid in the recovery of the plants.  At the end of the season I will reevaluate my "insurance"program and look for different strategies for next year. 

What can you do?  Use the divot mix in the carts and on the tee boxes.  Increasing bentgrass populations will only make your course a better place to play and easier for me to manage!

Stay tuned for more ABW updates and Ill see you out in the fairways!


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