Poa Annua Seedhead Suppression + Snow Mold Control on Cool Season Turf

A lot goes into a Poa annua seedhead suppression program on greens. Here’s what you need to know about application timing and what you can do if you missed the first, late fall Proxy spray.

Considerations before the applications:

• The timing of core aerification. Completing an application within one week to 10 days of aerification is not advised because recovery and fill in can be minimized.
• Frost. Using this program when there is a threat of frost can cause discoloration.

The new Proxy Poa annua Seedhead Suppression Program:

Historically, Poa annua seedhead suppression was undertaken in 2 applications in the spring based on temperature and the growing degree day model. Now, superintendents are using Bayer’s Proxy and doing two applications, one in the late fall and a second in the spring. After the final mowing, the fall application (primer application) is applied in combination with a snow mold application to prime the plant with Proxy (ethephon) before winter.

The second application in the spring is applied based on the following observations:

• The Poa annua plant being in the boot stage, which means you can feel the seedhead down in the sheath of the plant, but cannot see it.
• The initial sign of forsythia bloom
• Growing degree day totals (check growing degree days with www.gddtracker.net)

Tank-mixing a low rate of an iron + nitrogen fertilizer with your PGR was a common practice with the older version of the seedhead suppression program, and it is still used with the new program timing. This will reduce any discoloration and improve the efficiency of your seedhead control program. Tank-mix partners such as Foliar-Pak Amperage or CarboSential Fe Turbo are perfect here. Note: adding fertilizer to the late fall (primer) spray is not suggested.

Some superintendents are making additional apps of Proxy throughout the growing season. What are the benefits of continuing Proxy sprays beyond the seedhead suppression window: growth and clipping reduction, overall plant health, and maintaining consistent green speeds. The Proxy label allows a maximum of 30 ounces per 1000 sq ft per year, which is six applications at the 5 ounces per 1000 sq ft rate.

What should you do if you missed the fall application?

Look to the original Proxy program for seedhead suppression, which would be a minimum of two applications in the spring, typically one month apart (based on the initial sign of forsythia bloom, the boot stage of Poa plant, the growing degree day model, and temperature).

A note for spring snow mold control:

If you did not complete your fall snow mold spray, or in the unlikely event you made your app and disease is present, what can you use on greens? Use a curative fungicide. A tank mix of Chlorothalonil mixed with Iprodione, which equates to ArmorTech CLT 720 + ArmorTech IP 238, works well.

For more information on Poa annua seedhead suppression, contact your ATS sales representative or visit www.backedbybayer.com (search Proxy) for the product label and more details on Proxy use.