Allelopathic Effect of Different Concentrations of Aqueous Extracts of Nine Weeds Species on Seed Germination and Seedling Characteristics of Anise (Pimpinella anisum)

In order to evaluate the allelopathic effect of aqueous extract of nine weeds species on Anise (Pimpinella anisum) seed germination and seedling growth characteristics, an experiment was conducted in the Laboratory of Yasouj University in 2014.This experiment was carried out as factorial with the aqueous extracts of nine weeds species, as the first factor, in different concentrations (10, 20, 30, 40 and 50 g.l-1 ), as the second factor, in a completely randomized design with four replications.The results showed that interactions between different weed aqueous extracts and concentrations had a significant impact on the germination percentage and rate, root and shoot length and weight, and vigor of anise seeds at 1% probability.The most allelopathic effects on germination percentage and rate were observed in 10 g/l of the aqueous extract of Cowherb and Corn Buttercup, in 20 to 30 g/l of Corn Buttercup and Whitetop, and in 40 to 50 g.l-1 of Corn Buttercup, Whitetop, Wild lettuce and Cowherb, which completely stopped seed germination in Anise.