It can take a lot of effort to choose the optimum post program for your conditions, but it's worth it. He predicts the level will keep growing. New weed killers are mainly post-emerge, and they're providing weed control that was never dreamt of a decade ago. As a first step, Sikkema recommends, split the post-emerge options into chemicals that kill grasses or broadleafs or both. Crop safety is excellent.
Timing is one to eight-leaf.
Roundup Ready will kill most emerged weeds. First to break through may be buckwheat and lady's-thumb. Supply of resistant hybrids is tight. So far, there aren't any tankmixes on the label to provide residual control, which Sikkema says may be more important in wide-row corn than in drilled soybeans. It has a narrower application and must be sprayed by the four-leaf stage of the weeds.