Beware In Colorado

On the heals of my previous post about treating Poa Annua comes a turn of events.  If you are brave enough to apply Xonerate be sure to read the product label not once, not twice or even a third time of which might not be enough to truly understand the product being applied.  I have found it's what is not on the label that can give the best advice on how to use a product properly.  Unfortunately this knowledge comes with a price.  It seems as this information is only available after the fact of injury occurring to the desired plant species which in our case was  Bentgrass. This information was given to me more 30 days after the product was registered for use in Colorado and the application protocol had apparently changed.  Far too late for me or anyone who had applied the product per label instructions.

In my opinion Arysta LifeScience the producers of Xonerate herbicide was only concerned with getting the product to market without thoroughly testing it in all markets before release.  The latest and greatest Poa control product can yield a fortune in revenue coming back into the company that can expedite the return on investment.  This was clearly the case in Colorado.  In the last week I have received several phone calls from fellow Superintendents in Colorado who are experiencing the same if not worse injury to Bentgrass. To make matters worse the product Xonerate had little or no control on the Poa Annua which it is supposedly works so well on.  Most of my Poa that was treated couldn't look healthier, while the amount damage that occurred to the Bentgrass  makes this product unusable for me going forward.  This is the exact opposite of how this product has been marketed.

I believe a big factor in using this product in Colorado was overlooked and or underestimated.  Xonerate works by inhibiting Photosynthesis within the plant (specifically Poa Annua)  and is absorbed through both  the leaf and through the root system. The combination of  low humidity and significantly higher intensity of sun rays appear to effect how the product is absorbed by the non target species (Bentgrass).  More research and testing needs to be done on this matter.

We as Golf Course Superintendents are always looking for products to improve the overall health and playability of the golf course and it's times like this that some of these latest and greatest product make matters worse. If there are changes to application protocols manufacturers need to tell someone in a proactive manner , don't keep this information internally let the sales reps know so they can effectively communicate to the end user.

So if your a Golf Course Superintendent in Colorado considering using Xonerate, I would think long and hard before taking that first step because you will get burned. Just ask me.