As the season comes to an end, it is not too early to start planning for next spring. Specifically, Poa annua seedhead suppression next spring can be improved by applying ethephon (Proxy) to dormant turf this fall or early winter. This program has been utilized in the Northeast for the past several years and continues to be used more commonly with great results. The following points outline how to utilize ethephon at the end of the season and again next spring to improve seedhead suppression:
Apply ethephon after the last mowing of the season at 5 ounces per 1,000 square feet. The ethephon can be applied as a tank mixture with snow mold fungicides without negatively affecting control of seedheads or snow mold.
Two applications of ethephon should be made the following spring with the traditional timing. The fall application provides greater flexibility for the timing of the first spring application.
The first spring application of ethephon should not include trinexapac-ethyl (Primo) because it may delay spring greenup. However, the second application should include trinexapac-ethyl.
The level of seedhead suppression achieved from growth regulator applications is difficult to evaluate without a check plot, but research and field observations both show that applying ethephon in the fall after the last mowing helps to improve seedhead suppression the following spring.
Northeast Region Agronomists:
Adam Moeller, director, Green Section Education – amoeller@usga.org
Darin Bevard, director, Championship Agronomy – dbevard@usga.org
Elliott Dowling, agronomist – edowling@usga.org
Paul Jacobs, agronomist – pjacobs@usga.org