On-line version ISSN 1678-4596
OLIVEIRA, Andreya Kaliana de; COELHO, Maria de Fatima Barbosa; MAIA, Sandra Sely Silveira and DIOGENES, Francisco Esio Porto. Allelopathic activity of extracts from different organs of Caesalpinia ferrea on lettuce germination. Cienc. Rural [online]. 2012, vol.42, n.8, pp.1397-1403. ISSN 1678-4596. http://dx.doi.org/10.1590/S0103-84782012000800011.
Allelopathy can affect many aspects of plant ecology, including the occurrence, growth, plant succession, community structure, dominance, diversity and productivity of plants. The aim of this study was to evaluate the allelopathic potential of various organs of jucá (Caesalpinea ferrea) on seed germination and seedling development of lettuce (Lactuca sativa). It was used in a completely randomized 2x5 factorial arrangement, with two extraction methods (25 and 100°C) and concentrations of crude extract (0, 25, 50, 75 and 100%) for each organ evaluated: leaves, stem bark and mature pods of C. ferrea in four replications of 25 seeds of lettuce 'Monica SF FI'. The characteristics evaluated were germination percentage (PG), germination speed index (IVG), percentage of normal seedlings (PN) and abnormal (PA), shoot length (CPA) and root length (CR) of lettuce seedlings. The extracts of leaves and pods of C. ferrea obtained the hot (100°C) reduced the germination percentage of L. sativa compared to control (0%). At higher concentrations of the extracts of all organs were high PA (atrophy of the root, burning and darkening of the radicle, the bending caulículo, negative geotropism) and lower CPA and CR compared to control. The extracts of different organs of C. ferrea show allelopathic activity affecting the development of lettuce seedlings.
Keywords : Jucá; Lactuca sativa L.; allelochemicals; weed.