Phytotoxicity Evaluation of Poacure(Methiozolin) on Different Fine Fescue Species.

PoaCure (Methiozolin) is a relatively new herbicide that has been reported to selectively control annual bluegrass (Poa annua L.) as well as some other grassy weeds in various cool and warm season turfgrasses of different cutting heights. PoaCure is particularly effective on putting greens, since its selective and slow activity allows creeping bentgrass to cover the void left by annual bluegrass. However, PoaCure has rarely been tested in fine fescue turf.The objective of this study was to evaluate phytotoxicity of PoaCure on different fine fescue cultivars(or experimental materials). Nine different populations of fine fescues( Chewings Fescue: 14W2 Comp, Fairmont, Survivor; Hard Fescue: 14H4 Comp, Stonehenge, Oxford; Strong Creeping Red Fescue: FT345, Miser, Fenway) were sprayed with PoaCure (Methiozolin) at five different rates 0.47, 0.94, 1.40, 1.87, and 2.34 kg ai ha^-1, and four different application times, four weeks before seeding (4 WBS), two weeks before seeding (2 WBS), at seeding (AS) and two weeks after germination (2 WAG). Digital images of each pots were taken with a light box biweekly after germination to generate green percentage cover using SigmaScan. Above ground tissue was harvested 8 weeks after germination for fresh and dry weight measurement. Significant reduction in germination was observed when PoaCure was applied before emergence for all tested application rates. . It was relatively safe to apply PoaCure two weeks after germination, however, reduction in green percentage cover and biomass was also observed. ANOVA analysis showed cultivar, application rate, application timing all had a significant effect on green percentage cover. Interaction between rate and application time was also significant, suggesting that changes in application rate will affect the green percent coverage of fine fescue differently depending on the application timing.