Dual and Frontier can be applied preplant incorporated or preemergence. Some navy and black bean varieties are more tolerant to Dual than to Frontier. Weed Spectrum With adequate, timely rainfall for herbicide activation, all of these herbicides provide very good control of common annual grasses. The herbicides vary in their activity on broadleaved weeds and yellow nutsedge. For pigweed control, each of the herbicides except Prowl is rated good.
Prowl is rated fair.
For velvetleaf, Prowl will provide some control and is rated fair. The other herbicides have little activity on velvetleaf. Prowl has no activity on yellow nutsedge. Details of the effectiveness of these herbicides are available in the 1996 Weed Control Guide, MSU Extension Bulletin E-434. The herbicide requiring the most rainfall is Prowl.