Pre-Emergence Weed Control in Soybeans with Mixtures of Two Herbicides

Several herbicides have been tested for pre-emergence weed control in soybeans. PCP (sodium pentachlorophenate) has given good pre-emergence weed control in soybeans but relatively high rates of 15 to 20 lb/A were required. Although CIPC (isopropyl N–(3–chlorophenyl)carbamate) and NPA (N–1–naphthylphthalmic acid) have given promising results in some tests they have not been uniformly good; CDAA, on the other hand, has consistently controlled annual grasses but not broadleaf weeds.