Combinations of herbicides applied preplant incorporated and preemergence plus at layby were evaluated in corn (Zea mays L.) at three Nebraska locations in 1977 through 1980 for their effectiveness in providing season-long weed control. Pendimethalin [N-(1 -ethylpropyl) - 3,4-dimethyl - 2,6 - dinitrobenzenamine], pendimethalin + atrazine [2- chloro - 4 - (ethylamino) -6 - isopropylamino) -s- triazine ], metolachlor [2 - chloro - N - (2 - ethyl - 6 - methylphenyl) - N - (2 - methoxy -1 - methylethyl) acetamide], alachlor [2 - chloro -2′,6’ - diethyl - N- (methoxymethyl)acetanilide], cyanazine {2 -[[4 - chloro- 6 - (ethylamino) - s - triazin-2 - yl] amino] -2 -methylpropionitrile}, and cyanazine + atrazine were shown to be selective to corn and effective in controlling late - germinating weeds. Irrigated - corn yield was not increased by layby herbicide applications on the weed species and weed densities present in these experiments.