EVALUATION OF TRINEXAPAC-ETHYL (PALISADE) ON KENTUCKY BLUEGRASS GROWN FOR SEED IN CENTRAL OREGON
The growth regulator, trinexapac-ethyl (Palisade), was evaluated on commercial Kentucky bluegrass seed fields (var. ‘Geronimo’ and ‘Merit’) near Madras, Oregon from 1999 to 2003. Trinexapac-ethyl was applied at rates from 200 to 600 g a.i. ha-1 and at growth stages from two nodes detectable (Feekes 7) to pre-anthesis (Feekes 10.5). Compared to untreated plots, yields increased by an average of 31 percent across the five years of the study with the best-performing trinexapac-ethyl application. Applications at detection of the second node produced the greatest increase in yield. The effect of application rates varied over the years, but 400 g ai ha-1 generally maximized yield increases. Application when the heads first became visible (Feekes 10.1) had the greatest effect on plant height and lodging.