Compounds of the formula and their agriculturally suitable salts wherein Q is O, S or R, R2, R3, R4 and R6 are various organic groups, or in some cases H; R5 is H, CH3 or OCH3; R1 is a pyrimidine or tirazine residue; and W is O or S; are useful for the regulation of plant growth and/or as pre-emergance or post-emergence herbicides. The compounds can be prepared e.g. by reacting an appropriate benzenesulfonyl isocyanate or isothiocyanate with an appropriate aminopyrimidine or aminotriazine. The compounds can be formulated for agricultural use in conventional manner. Also the production of isocyanates of the formula wherein the substituents R, R2 and R3 are previously defined, is described, which are used as raw material for the preparation of the compounds with the above-mentioned formula.
