Effect of plants allelopathic on germination, biochemical and enzymic activity of weeds

In order to evaluate the allelopathic effects of aqueous extract of sorghum, eucalyptus, helianthus annuus and nicotiana sylvestris on some germination, biochemical and enzymes of two weeds of avena fatua and sinapis arvensis an experiment was conducted in factorial based on completely randomized design with three replications at in Seed Technology Laboratory, Faculty of Agriculture, Shahed University, Iran in 2018. Four concentrations (control, 5, 10 and 20 percent) from four plants (sorghum, eucalyptus, helianthus annuus and nicotiana sylvestris) and two weed seeds (sinapis arvensis and avena fatua) were the treatments. The results of analysis of variance showed that germination percentage, germination rate, seedling length, seedling dry weight, lipid peroxidation and catalase activity of two weeds at 1% level were affected by different concentrations of aqueous extracts of plants. The results showed that increasing the concentration of aqueous extract of the plant, percent and germination rate, seedling length, seedling dry weight, catalase activity of two weeds decreased however their lipid peroxidation increased. In different concentrations of the aqueous extract of the plant The highest rate was affected avena fatua  the highest influence than sinapis arvensis  and the highest inhibitory affected was observed at a concentration of 20%. Different concentrations of aqueous extract of sorghum compared to other aqueous extracts of plants had a greater inhibitory affected on weeds, so that 20% concentration resulted in more inhibition of both weeds. This aqueous extracts showed the most allelopathic effect, which could be a promising way to produce herbal extracts of natural origin.