Abstract: Compounds of the formula ##STR1## wherein n is 1 to 5 and the/each X is hydrogen, halogen, cyano, nitro, optionally substituted alkyl or alkoxy alkenyloxy, alkynyloxy, haloalkylthio, alkenylthio or alkynylthio;m is 0 or 1 to 3 and the/each Y is halogen, alkyl or haloalkyl;Z is oxygen or sulphur;andR.sup.1 and R.sup.2 each, independently, is hydrogen, alkyl optionally substituted by halogen, hydroxy, cyano, alkoxy, alkylthio, alkoxycarbonyl, or mono- or di-alkylamino, alkenyl, alkynyl, hydroxy, alkoxy, alkenyloxy, alkynyloxy, alkoxycarbonyl, amino, mono- or di-alkylamino, alkoxycarbonylamino, arylamino, dialkylcarbamoyl, cycloalkyl, or optionally substituted cycloalkylalkyl;orR.sup.1 and R.sup.2 together form an alkylene chain optionally interrupted by oxygen, sulphur or --NR--, R being hydrogen or alkyl;are herbicides.

Abstract: Phenoxy phthalide derivatives having the general formula II: ##STR1## wherein R.sub.1 represents a hydrogen or halogen atom or an alkyl or haloalkyl group; R.sub.2 and R.sub.3, which may be the same or different, each independently represents a hydrogen or halogen atom or an alkyl, haloalkyl, nitro or cyano group; R.sub.4 represents a saturated alkyl group; R.sub.5 represents an unsaturated alkyl group; and X represents an oxygen or sulphur atom, are useful as herbicides.

Abstract: Compounds of the formula ##STR1## wherein the symbols have assigned meanings, and their use as herbicides.

Abstract: Herbicidal heterocyclic pentalenes of the formula: ##STR1## wherein the symbols have assigned meanings.

Abstract: Use as herbicides of, and herbicidal compositions containing as active ingredients, compounds of the formula: ##STR1## wherein the symbols have assigned meanings.