Texas, USA 2010 - International Herbage Seed Group

Evaluation of Palisade (trinexapac-ethyl) on fifteen Kentucky bluegrassvarieties grown for seed in central OregonM.D. Butler & R.P. Affeldt, 850 NW Dogwood Lane, Madras, Oregon 97741,E-mail: marvin.butler@oregonstate.eduAbstractThe growth regulator, Palisade (trinexapac-ethyl), was evaluated on 15 Kentucky bluegrass (Poapratensis L.) varieties grown for seed at the Central Oregon Agricultural Research Center. Oneset of plots is a first-year stand and the other is a second-year stand. The influence of Palisade onseed yield, plant height, and lodging were documented. Treatments were applied at the bootstage and varieties were harvested based on maturity. Seed yields were significantly increasedfor 12 of 15 varieties in the first year field, and 4 of 15 in the second year field. Application ofPalisade uniformly reduced plant height and decreased lodging, with the exception of one datapoint.IntroductionResearch to evaluate Palisade on Kentucky bluegrass was conducted in commercial seed fieldsof „Merit‟ or „Geronimo‟ from 1999 to 2003. Yields were increased by 31 to 36 percent 4 of the5 years when Palisade was applied at 22 oz/acre from the second node (Feekes 7) to heads justbecoming visible (Feekes 10.1). Late application when the heads extended just above the flagleaf (Feekes 10.4) produced the greatest reduction in plant size, while plants tended to outgrowthe effect of earlier Palisade applications. No differences between treatments in weight per 1,000seeds were observed, and percent germination was not adversely affected.Methods and MaterialsThis research initiated in 2007 was conducted at the Central Oregon Agricultural ResearchCenter (COARC) near Madras. A split-plot design was used, with 10-ft by 60-ft main plots and 310-ft by 20-ft subplots. Subplots were randomized and included Palisade, Beacon(primisulfuron), and an untreated check in the first-year field planted to 2008, and Palisade andan untreated check in the second-year field planted during 2007. Main plots were replicated fourtimes in a randomized complete block design. Palisade was applied at 24 oz/acre on May 8, 2009when most varieties were in the boot stage.Application was made with a CO 2 -pressurized, hand-held boom sprayer at 40 psi and 20 gal/acrewater using TeeJet 8002 nozzles. Plant height was measured in the first-year field on May 22 andJune 3 and in the second-year field on May 27 and June 3. Percent lodging was estimated on July1. A section 6-ft x 17 ft of each plot was swathed as varieties matured from July 2 to 9. This wasfollowed by combining of the plots at an appropriate timing. Equipment used was a plot-sizedswather and Wintersteiger plot combine. Seed samples were transported to the Hyslop Farm near165