| 摘要 |
The herbicide contains, as active substance, novel 3-phenoxy- alpha -phenoxyalkanecarboxylic acid derivatives of the formula I <IMAGE> in which the substituents R1, R2, R3, R4 and R5 have the meanings defined in Patent Claim 1. It is suitable for the selective control of weeds, especially dicotyledons in monocotyledonous crops, such as cereals, maize and rice. It has a pre-emergence action, but should advantageously be used post-emergence. The active substances are prepared in a known manner by reacting a trifluoromethylhalobenzene with a 4-hydroxy- alpha -phenoxyalkanecarboxylic acid derivative or by reacting a 3-hydroxy-diphenyl ether with an alpha -halocarboxylic acid derivative. |
