Análise do potencial alelopático de hymenolobium petraeum ducke (Fabaceae)

Abstract

The positive or negative effect of compounds released on the soil in which one plant has on another is called allelopathy. This secondary metabolism can prejudice a multitude of plants within an agricultural crop. To avoiding herbicides, an alternative for farmers is the production of composting using materials that could possibly be discarded, as is the case with wood sawdust. Based on this assumption the present work aims to test if the sawdust of Hymenolobium petraeum Ducke has some allelopathic effect on the germination and growth of lettuce, corn and beans. The present work had two distinct approches: 1. allelopathy test in pellets; 2. Allelopathy test after in organic compound. In the first test, total germination (GT), germination speed index (IVG), growth variables of lettuce using a control group (T0) with distilled water, and T1, T2 and T3 treatments with sawdust extracts in concentrations of 5%, 7.5% and 10%, respectively. In the second test, organic compounds with H. petraeum sawdust were prepared in concentrations of 1: 2 and 2: 2 (kg of vegetables, fruits and vegetables : kg of sawdust) was used in treatments C1 and C2. For the control group (C0), commercialized substrat was used. The test in pellets with lettuce, and test of organic compound, with corn, showed negative allelopathies in the growth of stem and root, respectively. The test in organic compound with bean showed systemic negative allelopathy, with great mortality of seedlings and consequent decrease in germination (GT and IVG) and growth (stem and root length). Thus, the negative and differentiated allelopathic effects of the sawdust the H. petraeum can be perceived, acting punctually in the corn and lettuce, and systemically in the beans.