Respostas alelopáticas de piper umbellatum l. (piperaceae) em sementes de alface (lactuca sativa l.)

Abstract

Allelopathy can be defined as a phenomenon by which products of the secondary metabolism of plants are released into the environment and interfere with other plants. In order to verify the allelopathic potential of Piper umbellatum, extracts were tested using germination bioassays and growth, lettuce was used as target plants. In bioassays, the aqueous extracts were used in concentrations of 2,5%, 5%, 7,5% and 10%. The aqueous extracts caused a reduction in the total germination of lettuce seeds and caused slow germination. In the growth experiment, the extracts of P. umbellatum significantly reduced the survival rate of the seedings; in the surviving seedings there was a growth stimulus in relation to the control for the concentrations of 2,5% and 10%. However, Piper umbellatum presents strong allelopathic potential in seeds and lettuce seedlings.