Fluroxypyr plus clopvralid comparison to other postemergence herbicides in soring wheat

摘要

A study was conducted at the University of Idaho Research and Extension Center near Kimberly, Idaho to evaluate weed control with a fluroxypyr and clopyralid premixed formulation when applied to spring wheat. 'Klassic' was planted April 28, 2006 at 115 Ib/A. Experimental design was a randomized complete block with four replications and individual plots were 8 by 30 ft. Soil type was a Portneuf silt loam (5.3% sand, 75.7% silt, and 18.9% clay) with a pH of 8.1, 1.95% organic matter, and CEC of 16.4-meq/100 g soil. Herbicides were applied May 19, 2006 with a CO_2-pressurized bicycle-wheel sprayer with 11001 flat fan nozzles calibrated to deliver 10 gpa at 21 psi. Environmental conditions at application were as follows: air temperature 80 F, soil temperature 65 F, relative humidity 36%, wind speed 3 mph, and 15% cloud cover. Kochia (KCHSC), common lambsquarters (CHEAL), and redroot pigweed (AMARE) densities averaged 24, 8, and 2 plants/ft~2, respectively. Application began at 1145 hours. Crop injury only was evaluated 11 days after treatment (DAT) on May 30 and crop injury and weed control were evaluated visually 24 and 45 DAT on June 12 and July 3, respectively. Grain was harvested August 9 with a small-plot combine.