HERBICIDAL ARYLOXY- AND ARYLAMINO-INDANES

A compound of formula (I) : in which Ar is an optionally substituted aryl or heterocyclic ring system; W is O or NR where R is hydrogen or lower alkyl; A is=CH or >CH2 and B is=C-R , > C=R such that -B-A- is where R is H or CR R XR ; or -B-A- is where CR R is CH-CR R XR , CH-OCR R XR , C(R )OCOR , CR R , C(R ))OCOR , C(R )OR , C(OR )OR , or CH-CH2(CO2R ); or -B-A- is where R5 is =CR XR , =NOCR R XR , =NOR or =NOCOR . where X is (CH2)n, CH=CH, CH(OR )CH2, COCH2; and n is O, 1 or 2; R and R are independently selected from H, optionally substituted alkyl, alkenyl or alkynyl, halogen, NR R , or R and R together with the carbon to which they are attached form an optionally substituted alkenyl or cycloalkyl group; R is CO2R , CN, COR , CH2OR , CH(OH)R , CH(OR )R , CSNH2, COSR , CSOR , CONHSO2R , CONR R , CONHNR R , CONHNR R R R , CO2R or COON=CR R ; R is an agriculturally acceptable cation; R is an agriculturally acceptable anion; R , R , R , R and R are independently selected from H or an optionally substituted alkyl, alkenyl, aryl or alkynyl group or any two of R , R , R and R , R together with the atom to which they are attached form a cycloalkyl or heterocyclic ring, and R and R may additionally be a heterocyclic ring, provided that when B is CR R or C(R )OR , R and R are not both hydrogen.