As July arrives, golf courses in southern Arizona, southern Nevada and the Coachella Valley that enacted a proactive strategy to encourage bermudagrass recovery from overseeding are enjoying watching the sun set on the ryegrass season. For these courses, the overseeded ryegrass has been eliminated or nearly eliminated. In its place is a dense, robust stand of bermudagrass. Conversely, for those courses choosing to “hang on” to the ryegrass, the current turf stand is a mix of ryegrass and bermudagrass. These courses are seeing signs of thin turf or bare ground where the ryegrass has already died. As more humidity arrives and overnight temperatures remain hot, the ryegrass will die and there may not be healthy bermudagrass underneath for quite some time.
As we reflect on the transition process in 2021, what stands out are the positive results seen at courses who were proactive and utilized chemicals such as penoxsulam (Sapphire) and pinoxaden (Manuscript) early in the season, as early as late February. Many courses using these chemicals at low rates – e.g., 4-8 ounces for Sapphire and 0.5-3.0 ounces of Manuscript per acre – begin in mid to late March and continue on three-week spray intervals, making a total of three to five applications.
For those superintendents that view the chemical transition process with some trepidation, I encourage you to reach out to courses who have used this technique. One such superintendent was Chris Bien at the Desert Willow Golf Resort in Palm Desert, California. Bien had not used a chemical transition strategy until this year. He began with a trial at the practice facility on March 25, followed the next day by applying Sapphire at 8 ounces per acre to several holes on each of his two golf courses. By mid-April, Chris was so happy with the early results that he sprayed the entire Firecliff course and the holes sprayed in March received a second application. The third and final applications were made in mid-May. By June 15 the bermudagrass population was estimated at 99%. In previous years, the bermudagrass comprised only about 60% of the fairways by mid-June. This was all done without any disruption to the playing surface during the primary revenue months!
The proactive transition model is clearly working well. Please reach out to your regional USGA agronomist if you would like more information on this process.
West Region Agronomists:
Brian Whitlark, senior consulting agronomist – bwhitlark@usga.org
Cory Isom, agronomist – cisom@usga.org