UNDESIRED VEGETATION SUCH AS CRABGRASS, DOWNEY BROME, GIANT FOXTAIL, YELLOW FOXTAIL, BARNYARD GRASS, FLAX AND WILD OATS ARE COMBATED BY PRE-EMERGENT APPLICATION OF AT LEAST ONE COMPOUND BELONGING TO A CLAS OF SUBSTITUTED N-BENZYL AMIDES OF ALKANOIC AND BENZOIC ACIDS, PARTICULARYLY IN THE PRESENCE OF SEEDS OF SUCH CROPS AS COTTON AND SOYBEANS. ILLUSTRATIVE OF COMPOUNDS WHICH ARE VERY EFFECTIVE AGAINST SEVERAL SPECIES OF GRASSES AS WELL AS SOME BROADLEAF WEEDS IN THE PRESENCE OF SOYBEANS AND COTTON ARE TWO WITH THE FOLLOWING STRUCTURAL FORMULAS:

1-(PHENYL-CH2-N(-CH(-CH3)2)-CO-),3,5-DI(CL-)BENZENE AND

(CH3-CH(-CH3)-N(-CO-C(-CH3)3)-CH2-)BENZENE