Herbicides for sainfoin

We continue to get quite a few questions about weed control in sainfoin. Unfortunately, there are very few herbicide options currently registered for use in sainfoin (only 6 different active ingredients). We are investigating some additional herbicides in ongoing research trials. Although several herbicides look promising in our trials, these potential options will not be registered in time for the 2013 growing season (in fact, it is a distinct possibility they never will be). The following table lists currently registered herbicides for sainfoin in Wyoming. There are no herbicides that we can use for broadleaf weed control in actively growing sainfoin. Glyphosate and paraquat can be applied to control any green, actively growing weeds prior to sainfoin green-up, but the application window is very narrow, especially if targeting summer annual weeds. Winter annual weeds like some mustards and downy brome (cheatgrass) may be controlled well with dormant applications. Metribuzin might provide limited residual weed control at higher application rates, but must also be applied when the sainfoin is dormant. Metribuzin also has a 28 day pre-harvest interval, which means you cannot cut or graze the sainfoin until at least 28 days after application.