Models Explaining the Allelopathic Coefficients between Glycyrrhiza glabra L. and Cyperus rotundus L. of Aqueous Extract and Residual Powder on Corn and Bean

In order to investigate models explaining the allelopathic effects of aqueous extract of different parts (Roots, Stems, Leaves and Flowers) of Licorice (Glycyrrhiza glabra L.) and Purple nut sedge)Cyperus rotundus L.(on germination rate, Root and Shoot length of Corn (Sc 704) and Bean (Cv Talash) experiment of based on Completely Randomized Design with four replications was conducted. treatments included control (distilled water), 25%, 50%, 75% and 100% of different parts of Licorice and Purple nut sedge. There were significant differences between germination rate, Root and Shoot length of Corn and Bean with different concentration of aqueous extracts of Licorice and Purple nut sedge, Results showed that increasing the extract concentration decreases seedlings growth. Linear models obtained based on regression analysis were almost significant in all cases and showing that Licorice and Purple nut sedge have significant allelopathic effects on Corn and Bean. Mean allelopathic coefficients of the effects of Licorice on Corn, Licorice on Bean; Purple nut sedge on Corn and Purple nut sedge on Bean was -5.68, -3.72, -1.10, -1.44 (unit) respectively. These allelopathic plants may be considered in producing organic herbicides.