Allelopathic activity of extracts of Schinus molle L. leaves on the germination and early growth of radish

Abstract

This study aimed to evaluate the allelopathic activity of leaf-soft mastic (Schinus molle L.) on germination and early growth of radish (Raphanus sativus L.). Leaf extracts were prepared at concentrations of 2, 4 and 8%. pH and osmotic potential were also performed from the extracts. Germination bioassay consisted of four replicates of 25 seeds of radish distributed in Petri dishes with germitest paper and 7 mL of extract or water and kept at 25 ° C in B.O.D. for five days. Germination percentage (PG), germination rate (VG), germination speed index (IVG) and Index of allelopathic effect (RI) were determined. For bioassay initial growth, seeds were germinated (2mm protrusion of radicle) and transferred to Gerbox contained germitest paper and 15 mL of extract or water, staying seven days at 25 ° C in B.O.D. to evaluate the length of radicle and hypocotyl, mass fresh and dry, the water content and content of chlorophyll (a, b and total). Extracts of leaves S. molle affected negatively all parameters examined for germination (PG, VG, IVG and RI). For the initial growth, the extracts caused a reduction of radicle length and stimulated the growth of hypocotyl. The extracts also led to increased the fresh and dry weight but did not alter the content of chlorophyll. Thus, as the pH and osmotic potential did not affect the results, S. molle exerted allelopathic effect on radish.