Obtained results showed that studied chlorophenoxy herbicides are very effective in protection of winter wheat against most of the weeds. Sensitive weeds (Matricaria inodora, Capsella bursa pastoris) were killed eight hours after their application and less-sensitive weeds (Equisetum arvense) 19 days after treatment. MCPA residues declined within the wheat tissues during the next 96 hours. Side effect of the herbicides might be useful in control of the grain aphid, S. avenae.

An analytic method for determination of (4-chloro-2-methylphenoxy)acetic acid (MCPA) residues in soil under cereal cultivation was elaborated. Estrification of the herbicide with methanol has been performed and followed by solid phase microextraction (SPME). Obtained results showed traces of MCPA within the studied soil samples up to 8 weeks, after the herbicide treatment. The herbicide moved within the soil profile to 20 cm of depht. Possible application of the SPME/GC-MS method for monitoring of the MCPA residues within soil under winter wheat cultivation is discussed.