a cultivation prior to vine running (3 to 4 weeks after transplanting) and immediately followed by 0.75 pt Dual Magnum followed by a graminicide (Select, Poast, Fusilade) for grads control. Keep in my your state registrations as sweet potatoes usua require a special label. Also, Dual Magnum (active ingredient = S-metolachlor) is registered for application any time after transplanting until 60 days before harvest. Depending on your state, some states the label states that the maximum labeled rate is 1.3 pints/acre and must be applied in a single application. The best application timing will depend on what weeds are present in each production field. In production fields with nutsedges, Dual Magnum should be applied to a clean production field immediately after transplanting. Remember that S-metolachlor only controls yellow nutsedge, not purple. The standard 0.75 pt/acre recommendation has provided control of yellow sedge equivalent to higher rates. In fields where nutsedge is not present or at very low densities, Dual Magnum applications should be delayed until at least 10 days after transplanting. Why delay this application? Dual Magnum applications made immediately after transplanting and followed by moderate to heavy rainfall can result in modest plant stunting, reduced yields, and misshapen storage roots. Crop tolerance increases every day through at least 14 days after transplanting.