ALLELOPATHIC EFFECT OF Tephrosia cinerea L. (Pers.) PLANT EXTRACTS IN LETTUCE

Resumo

Allelopathy has been conceptualized as the direct or indirect effect of a plant onto another one through secondary metabolites, or allelochemicals spread in the environment, with the power to interfere in seed germination and increase or inhibit the development of neighboring plants. The objective of this study was to analyze the possible allelopathic effects of aqueous extracts of Tephrosia cinerea in the germination of lettuce (Lactuca sativa L.) seeds. The experiment has been carried out at the Laboratório de Nutrição Mineral de Plantas (Laboratory of Plant Mineral Nutrition)/UAEF/UFCG in Patos (state of Paraíba). We collected T. cinerea organisms, having separated the stem, leaves, roots fractions and the aerial part of the plant + roots, having prepared the extract at 20%. The experimental delineation that we adopted was entirely casualized, with five treatments and four repetitions (without extract, leaf extract, root extract, stem extract, aerial part extract + roots). The seeding was held in aluminum trays, with autoclaved sand as the substrate, setting 25 seed per tray. The calculation of the number of germinated seeds was made in a dailybasis, and, after a week of seeding, the next step was the deactivation, with the evaluations being performed regarding the length of the radicle and of the hypocotyl, as well as the height of the seedlings. The data collected in this research allows us to conclude that: the extracts obtained from T. cinerea plants has a negative impact on the germination of lettuce seedlings. Now, when it comes to the height of lettuce seedlings, it is affected by the use of leaf, stem and aerial part extracts + T. cinerea roots. It is crucial to make efforts in order to determine the existing constituents in the several parts of T. cinerea plants.