HERBICIDE COMPOSITIONS CONTAINING PYRIDYL-OXY-PHENOXY-ALKANCARBOXYLIC ACID AND PYRIDYL-OXY-PHENOXY-ALKANOL DERIVATIVES AS ACTIVE SUBSTANCES AND PROCESS FOR PREPARING SUCH COMPOUNDS

摘要

Phenol derivs. of formula (I) are new: (X is CF3, CHF2, CClF2, Br or Cl; T is O or S; Z is an organic gp. contg. N, O or S atoms or a metallic, ammonium or organic amine cation and is, or can be, hydrolysed and/or oxidised in plants or the soil to form a carboxy gp. which is in undissociated and/or dissociated form). - Pref. Z is CH(R1)-(Y)nR2 (where Y is an opt. unsatd. alkyl gp. contg. an even number of C; n is 0 or 1; R1 is H or 1-3C alkyl; and R2 is COOH or its alkali(ne earth) metal, ammonium or amine salt or lower alkyl ester). - (I) are herbicides effective for the control of grassy and graminaceous weeds. (I) are more effective than similar known cpds., the (R)-isomer being partic. active. (I) are tolerant to important broadleaf crops (e.g. cotton, soybean, sugar beet and rape) and certain cpds. are tolerant to cereal crops (e.g. wheat). These cpds. are also effective in controlling selectively perennial grassy weeds such as johnson grass, quackgrass, bermudagrass and dalligrass. Applicn. rate is 0.05-20 lb/acre post-emergence and 0.01-10 lb/acre pre-emergence.