The effects of phenoxy herbicide MCPA on nontarget vegetation in spring wheat (Triticum aestivum L.) culture

Abstract

The study examined the nontarget effects of phenoxy herbicide MCPA (4-chloro-2-methyl-phenoxy acid) on the morphological and physiological characteristics of spring wheat (Triticum aestivum L.) and weeds abundance under field conditions. The experiment was conducted in 4 mesocoms plots (0.1 a) from May to August 2012. The plants were sprayed directly with herbicide sprays solutions equivalent of recommended field application rate. The measured endpoints were: height of the shoots, length of the roots, the dry biomass, concentrations of chlorophyll a, b, carotenoids, malondialdehyde (MDA). The yield of wheat and residues of MCPA in wheat tissues and soil were also estimated. It was observed that herbicide slightly reduced spring wheat stem height (by 9%, p<0.05), increased root length (p>0.05). Dry weight of spring wheat stems and roots decreased by 14% (p<0.05) and 17% (p>0.05), respectively. The herbicide did not evoke significant effect on the content of photosynthetic pigments and MDA in plant tissues. MCPA herbicide residues were observed only in soil and stems of spring wheat and were 0.97 μg/kg and 0.047 mg/kg, respectively