the present invention is directed to compounds of the formula ## str1 ## wherein r 1 is c 1 - c 6 alkyl , c 5 - c 6 cycloalkyl , ## str2 ## each of r 2 and r 3 is taken separately and is independently hydrogen , c 1 - c 4 alkyl , c 3 - c 4 alkenyl , c 3 - c 4 alkynyl , c 3 - c 4 cycloalkyl or c 1 - c 3 alkoxy , or r 2 and r 3 are taken together with the nitrogen atom to which they are attached and form piperidine , morpholine or pyrrolidine ; each r 4 independently is halogen , c 1 - c 4 alkyl , c 1 - cphd 4 alkoxy , c 1 - c 4 haloalkyl , c 1 - c 4 haloalkoxy or cyano ; x is 0 or s ; and m is 0 - 3 ; with the provisos that when r 4 is c 1 - c 4 alkyl , that substituent exists at other than the 2 or 6 position of the phenyl ring ; and when r 2 is c 1 - c 3 alkoxy , r 3 is other than c 1 - c 3 alkoxy . these compounds exhibit activity as terrestrial herbicides , aquatic herbicides , and aquatic algicides .