Canola Herbicide Trial, Carrington, 2000.
The experiment was conducted on a minimum-till field and Heimdahl-Emrick loam soil with 6.2 pH and 3.3% organic matter at the NDSU Carrington Research Extension Center. The experimental design was a randomized complete block with three replicates. Herbicide treatments were applied to 5 by 25 ft plots with a hand-boom or hooded bicycle–wheel plot sprayer. PPI treatments were applied at 18.4 gal/A at 35 psi through 8002 flat fan nozzles on May 1 with 69 F, 23% RH, 90% clear sky, and 8 mph wind on a dry soil surface and incorporated with a roto-tiller at a 3- to 4-inch depth. ‘InVigor 2573‘ canola was planted at 700,000 PLS/A on May 3 in 7-inch rows at a 0.5- to 1-inch depth. POST treatments were applied at 9.2 gal/A at 35 psi through 8001 flat fan nozzles. POSTA treatments were applied on June 2 with 50 F, 77% RH, clear sky, and 8 mph wind to 3-leaf canola, 3- to 4-leaf foxtail, 1-inch tall to flowering wild mustard, and other annual broadleaf weeds were 1- to 3-inches tall. POSTB treatments were applied on June 16 with 51 F, 74% RH, 95% cloudy sky, and 11 mph wind to 6- to 8-leaf canola, 3- to 6-inch tall yellow and green foxtail, 6- to 15-inch tall common lambsquarters, 10- to 15-inch tall horseweed, 12-inch tall kochia, 1- to 4-inch tall redroot and prostrate pigweed, 6-inch tall Russian thistle, 2- to 15-inch tall wild buckwheat, and flowering wild mustard.
Visual crop injury was absent or negligible with all herbicide treatments (data not shown). Few differences in weed control were evident among herbicide treatments with the first and second visual evaluations (Table).
The third evaluation (canola at physiological maturity)
indicated that control of all weed species present was good to excellent (84 to
99%) with treatments that included trifluralin (Table). Weed control generally
was similar between application timings of glufosinate, but an advantage existed
with early application of glufosinate for Russian thistle control. Sequential
applications of glufosinate generally provided similar weed control as single
applications. Glufosinate at 0.44 lb/A generally did not improve weed control
compared to glufosinate at 0.36 lb/A.