| Abstract/Contents: | "This study was conducted on a mature stand of 'Penneagle' creeping bentgrass (Agrostis stolonifera) and annual bluegrass (Poa annua) at the Valentine Turfgrass Research Center, Penn State University, University Park. The objective of the study was to determine if selected materials could reduce the annual bluegrass population under simulated fairway conditions. This study was a randomized complete block design with three replications. Treatments were applied on several dates using a three foot CO2 powered boom sprayer calibrated to deliver 40 gpa and Betasan was applied at 80 gpa using two, flat fan, 11004 nozzles at 40 psi. The test area was maintained to simulate a golf course fairway. The test site consisted of approximately 45 percent creeping bentgrass and 55 percent annual bluegrass at the initiation of the study. Turfgrass discoloration was rated five times during the study. Only turfgrass treated with Velocity, alone or in combination with other materials, was rated below acceptable (7.0) at some time in the study. Turfgrass quality was rated five times during the study. Turfgrass quality was never rated below acceptable (7.0) on any rating date. Turfgrass spring color was rated twice during the study. On the April 13, 2006 rating date only turfgrass treated with Prograss, alone or in combination with other materials, was rated below 6.0. By the May 9, 2006 rating date, all turfgrass spring color was rated 9.0. The annual bluegrass population change was rated on May 9, 2006. Turfgrass treated with Trimmit plus Rubigan at 0.75 oz/1,000 ft2 with or without an 18-3-1 fertilizer applied at the June, 28, 56, 112, and 140 DAT timings, Trimmit plus Rubigan at 1.5 oz/1,000 ft2 applied at the June, 28, 56, 112, and 140 DAT timings, Velocity at 60 g ai/A June and 14 DAT plus Rubigan at 0.75 oz/1,000 ft2 June 14, 42, 70, and 98 DAT, Trimmit with or without Rubigan at 0.75 oz/M plus an 18-3-1 fertilizer applied at the June, 28, 56, 112, and 140 DAT timings with or without Betasan at 5.6 oz/1,000 ft2 applied at June, and 56 DAT timings, Trimmit plus Signature at 8 oz/1,000 ft2 plus an 18-3-1 fertilizer applied at the June, 28, 56, 112, and 140 DAT timings with or without Betasan at 5.6 oz/1,000 ft2 applied at June, and 56 DAT timings, Trimmit applied at the June, 28, 56, 112, and 140 DAT timings plus Rubigan at 0.75 oz/1,000 ft2 applied at the June, 14, 28, 42, 56, 70, 84, 98, 112, and 140 DAT timings, Prograss alone or in combination with Trimmit at any rate, and Trimmit plus Signature applied at the June, 28, 56, 112, and 140 DAT timings reduced the annual bluegrass population by 70% or more, significantly more reduction than untreated. It appears that annual bluegrass populations can be reduced in a mixed sward of creeping bentgrass/annual bluegrass using Trimmit, Velocity, and Prograss alone or in combination with a fertilizer, fungicides, and a preemergence." |
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