Cyclohexenonedioxothiochromanoyl derivatives of the formula I
where
X is oxygen, sulfur, S═O, S(═O)2, CR4R5, C═O or C═NR6, the other substituents are as defined in the specification, and and agriculturally useful salts thereof; processes for preparing the cyclohexenonedioxotheiochromanoyl derivatives; compositions comprising them, and the use of these derivatives or of compositions comprising them for controling undesirable piants.