Enhancing or Replacing Dinitroaniline Herbicides for Annual Bluegrass (Poa annua L.) Control In Overseeded Golf Course Fairways.

The study was conducted from 24 June to 22 July 2011, at the turfgrass research site at The University of Tennessee at Martin. Experimental design was a randomized complete block with three replications. Plot size was 3 m2.

   Turf was mowed three times weekly at a 2.3 cm height, and irrigated to maintain a well-watered status. Mepiquat chloride (MC), mepiquat pentaborate (MP), and trinexapac-ethyl (TE) were applied alone at each of the following rates: 0.40, 0.80, and 1.60 L/ha. Treatments were applied with a CO2 backpack sprayer calibrated to deliver 187 L/ha. A single application was made on June 24, and turf quality, turf injury, and clipping yield were evaluated 3, 7, 14, 21, and 28 days after application (DAA).

   Turf quality was rated visually on a scale from 1 to 9, where 1 = brown turf and 9 = dark green turf, with   < 7 being unacceptable. Turf injury was visually assessed on a scale of 0 to 100% with > 30% being unacceptable. Data was analyzed using ANOVA, and means were compared using Fisher’s protected LSD (α=0.05).