Seedhead Suppression

If you are a regular reader of this blog, you have surely picked up on my hatred of Poa Annua by now.  It is a horrible weed that makes my life miserable, however, it comprises close to 80% of the turf on some areas of this golf course, so it is a "necessary evil".  One of the worst evils of this plant is its physiological desire to produce a huge flush of seeds in the spring.

In the past we have been using a growth regulator called Proxy as a seedhead suppressor on the greens.  While it has mostly worked it has come with a bit of a price, mostly in its effect of causing soft and puffy surface conditions on the putting greens.  In a desire to try something different this year, we did some trials with a different product called Embark.

Embark has been used as a seedhead suppressor for Poa Annua in the golf industry for a long time.  However, it has seen somewhat limited use due to its effect of causing some yellowing and bronzing of the turf it is applied to.  Proxy in general does not have this effect, but it also is not as effective as a seed inhibitor.

This spring we continued our application of Proxy to all of the greens and collars, however we treated hole 16 with Embark instead.  While the Embark did cause some minor yellowing in days 7-114 after application, the rebound effect afterward has been dramatic.  The areas we applied Embark are almost seedhead free, and the Poa Annua is a deeper and darker green that the untreated areas.

The turf where Embark was applied showed minor bleaching a few
days after the application.

The rebound effect has been dramatic however.  4 weeks after the
initial application, the Embark applied area looks much better
than the untreated turf.

We also sprayed a trial strip of Embark at the beginning of 6 and 11 fairways.  These two fairways in particular have the highest Poa Annua concentration of any of the fairways on the course.  The results were fairly dramatic here as well.  We observed the same issue at the beginning, where treated turf looked a little off color for the first week, but so far weeks 3 and 4 after application we have seen some great effects.

The trial strip on 11 fairway shows that the Embark treated turf is much
greener, denser, and healthier than the untreated Poa Annua.

The timing of any of these growth regulators is crucial in order to achieve maximum Poa Annua seedhead suppression.  It is even more difficult to time here in the North where we have such dramatic temperature fluctuations in the spring.  We will be doing a few more trials with this product on some other areas of the course throughout the summer, in the hopes that we will be prepared to use this product extensively first thing next spring.