Secondary metabolites produced in some plant species can provoke development changes in other plants or even in other organisms. The objective of this work was to identify the possible allelopathic effects of the aqueous extracts of Joanesia princeps and Casearia sylvestris leaves in the germination and initial growth of Brassica oleracea cv. capitata, Lactuca sativa cv. grand rapids and Lycopersicum esculentum seedlings. Six concentrations of each extract (10, 30, 50, 70, 90 and 100%) were tested besides distilled water control. The aqueous extracts of J. princeps and C. sylvestris significantly reduced the seed germination percentage, initial growth of the aerial section and root system of all cultivated species in which they caused severe seedlings damage. The results indicate existence of allelopathic potential in J. princeps and C. sylvestris.
Joanesia princeps; Euphorbiaceae; Casearia sylvestris; Salicaceae; allelopathy; germination; growth
