Weed control with metam-sodium during establishment of Kentucky bluegrass

摘要

A study was conducted to evaluate winter annual grass weed and broadleaf weed control with using metam-sodium (Vapam~(R)) during the seedling establishment period of Kentucky bluegrass (KBG) grown for seed. The experimental area was located at the Hermiston Agricultural Research and Extension Center, Hermiston, OR. Downy brome and rattail fescue were broadcast seeded in the plot area on August 8, 2005 and incorporated with a spike-tooth harrow, and lightly irrigated to imbibe seed. Metam-sodium treatments were applied preplant on August 12, 2005. Treatments 3 and 6 used a chemigation simulator which applied 0.4 acre inches of water in two passes over the plots. Treatments 4 and 7 were applied at 0.6 acre inches of water with 3 passes of the chemigator over the plots. Treatments 5 and 8 were applied uniformly to the soil surface and incorporated with a roto-tiller + roller packer at 1 to 2 inch depth. Treatments included two rates of metam-sodium (15 and 30 gal/A) with each type of application method (i.e. roto-till or chemigation). The entire plot area was then irrigated to promote weed seed germination and to prevent metam-sodium volatility loss. The chemigation simulator was calibrated to apply water at 60 psi through flood-type nozzles. Plots were 6.7 ft by 30 ft, in an RCB arrangement, with 4 replications. Soil at the site was an Atkins fine sandy loam (71.6% sand, 18.9% silt, 9.5% clay, 1.1% organic matter, 6.8 pH, and CEC of 9.2 meq/100 g). Kentucky bluegrass (var 'Baron') was seeded on August 30, 2005 at 5 Ib/A on 11 in. row spacing. Weed counts were made September 26, 2005 (Table 2). Plots were hand-weeded and weeding time recorded for each treatment on October 10, 2005 (Table 2). Visual control of downy brome was rated on 5/17/06. Plots were swathed with a small plot swather on June 15, 2006 and harvested with a small plot combine on June 30, 2006. Yield results are shown in Table 2.