06/25/08 Cultural management of downy brome still important

Farm and Ranch June 25, 2008 It's been ten years now since the downy brome herbicide Maverick became available. In fact several more products have come on the market since and Washington State University weed scientist Joe Yenish facetiously says what we seem to have more of these days than downy brome is downy brome herbicides. However, the grassy weed continues to be a serious problem. Yenish told a recent dryland field day that the long term average for downy brome control from these herbicides is about 80 percent. So the herbicides are a complement to, but not a replacement for good cultural practices. Yenish: "The time to start managing downy brome is immediately post-harvest. Do some things to scratch that downy brome as you are doing your post-harvest residue management. Try to improve the soil-seed contact, especially in those heavy, heavy infestations that we saw two years ago. Try to flush out as much of that seed as we can. Kill it off with glyphosate or additional applications. That followed up with several other cultural methods of control means we are going to see a lot more return for our herbicide dollar." Yenish says there is also the issue of herbicide resistance. All the downy brome herbicides have the same mode of action. They are all Group II or ALS inhibitors. I'm Bob Hoff and that's the Northwest Farm and Ranch Report on the Northwest Ag Information Network