Postemergence Control of Broadleaf Weeds with F9009.

Research was conducted in 2009 and 2010 to evaluate the efficacy of F9009 for the control of ground ivy (Glechoma hederacea L.) at Egwani Farms Golf Course (Rockford, TN). Treatments were applied with a CO₂ backpack sprayer equipped with four 8002 flat-fan nozzles calibrated to deliver 281 L/ha. Treatments were initiated on May 26, 2009 and July 27, 2010 and included metsulfuron (10.5, 21, and 42 g ai/ha) and F9009 (183, 290, 300, 323, 430, 440, and 463 g ai/ha). Ground ivy control and bermudagrass injury were rated visually 1, 2, 4, and 8 weeks after treatment (WAT). Data were subjected to analysis of variance (ANOVA) and means were separated using Fisher’s Protected LSD (α= 0.05). No bermudagrass phytotoxicity was observed in either year regardless of treatment. Over a two year period, ground ivy control with metsulfuron at 10.5, 21, and 42 g ai/ha ranged from 0 to 5% 1 WAT and 12 to 60% 2 WAT. Ground ivy control with F9009 ranged from 40 to 72% 1 WAT and 87 to 100% 2 WAT. Few differences in ground ivy control were detected between treatments 8 WAT in either year. Research was conducted in 2010 to evaluate the efficacy of F9009 for the control of khakiweed (Alternanthera pungens HBK.) and prostrate knotweed (Polygonum aviculare L.) at Meadowbrook Golf Course (Lubbock, TX). Treatments were applied using a CO₂ backpack sprayer equipped with XR8004VS nozzle tips and calibrated to deliver 375 L/ha at 221 kPa. Treatments were initiated on August 18, 2010 and consisted of metsulfuron (10.5, 21, and 42 g ai/ha) and F9009 (323 and 463 g ai/ha). Weed control and bermudagrass injury were rated visually 1, 2, 4, 8, and 12 WAT. Data were subjected to ANOVA and means were separated using Fisher’s Protected LSD (α= 0.05). No bermudagrass phytotoxicity was observed throughout the length of the trial regardless of treatment. Initial knotweed control with metsulfuron was 33 to 50% 1 WAT, regardless of rate; while initial khakiweed control was 0 to 27%. F9009 exhibited moderate initial khakiweed (56 to 58%) and knotweed (50 to 52%) control 1 WAT, regardless of rate. Long-term control of knotweed with metsulfuron was 83 to 96% regardless of rate, while control with F9009 was 98 to 100% 12 WAT. Long-term control of khakiweed with metsulfuron was 62 to 81% regardless of rate, while control with F9009 was 86 to 91% 12 WAT.