Evaluation the allelopathic effects of wheat (Triticum auestivum L. cv. Pishgham) on the some metabolites’ content of redroot pigweed (Amaranthus retroflexus L.) under intercropping

Allelopathy refers to the beneficial or harmful effects of one plant on other plants, Including crop and weed species, from the release of biochemicals, known as allelochemicals, from plant parts by leaching, root exudation, volatilization, residue decomposition, and other processes in both natural and agricultural systems. Allelochemicals are a subset of secondary metabolites not required for metabolism (growth and development) of the allelopathic organism. For weed management purposes, allelopathy is considered as an important strategy of control. The aim of recent study was to determine the allelopathic effect of wheat as a crop with allelopathic potential on the content of some metabolites of redroot pigweed. For this purpose an experiment was conducted as factorial based on completely randomized design with three replications. Wheat and redroot pigweed was intercropped under greenhouse conditions in ratios of ۱۰۰ to ۰(as control) and ۵۰ to ۵۰. After harvesting the plants, redroot pigweed shoots were used to assessment of metabolites. The results showed that in the presence of wheat the total flavonoid content, total anthocyanin content, soluble and insoluble sugars content of redroot pigweed shoots decreased significantly compared to the control, but the content of total phenol and total protein of redroot pigweed shoots did not change significantly. The allelopathic effect of allelochemicals depends upon species and tissue concentration, movement, persistence and fate of such biochemicals in the soil. Concentrations of polyphenols under different stress do not follow a regular pattern. The reduction in sugar content can be attributed to the inhibitory effects of allelopathic compounds on the synthesis of photosynthetic pigments. The results of this study showed that the allelopathic effects of wheat are effective in controlling redroot pigweed. In order to enrich results of this research, the study of growth parameters and activity of the enzymatic defense system in both species is suggested.