POTENCIAL ALELOPÁTICO DO EXTRATO AQUOSO DE CASCAS DE JUREMA PRETA NO DESENVOLVIMENTO INICIAL DE ALFACE

Abstract

The paper aimed to evaluate the allelopathic potential of Jurema (Mimosa tenuiflora (Willd.) Poir.) on seed germination and seedling growth of lettuce. The study consisted of two experiments, each arranged in a completely randomized design with five treatments and four replications of 20 seeds: 1) stem bark extract of M. tenuiflora obtained in hot water (100 °C) and at concentrations of 0%, 25%, 50%, 75% and 100% of standard extract, 2) stem bark extract of M. tenuiflora obtained in cold water and the same concentrations. The extract was obtained by standard 50 g of bark in 500 mL of distilled water. We evaluated the germination percentage (G), germination speed index (GSI), percentage of normal seedlings (NP) and abnormal (PA), shoot length (CPA) and root (CR) in lettuce seedlings. All extracts were analyzed for pH and conductivity. The germination of lettuce was high (> 97%) and no significant difference between means of G and IVG in different concentrations of the extract pattern. No allelopathic activity of M. tenuiflora on the germination of lettuceseeds. The hot extract cause greater percentage of abnormal seedlings in lettuce. The aqueous extracts of bark of M. tenuiflora have phytotoxic effects on seedling growth of lettuce, and in higher concentrations drastically affect the length of the root and shoot.