Efeitos de resíduos foliares de Prosopis juliflora na germinação e crescimento inicial de espécies cultivadas.

Abstract

In almost all countries of the world can be evidenced cases of biological invasions, either as a natural phenomenon or as a result of human action. A very common example of biological invasion is the case of mesquite (Prosopis juliflora SW), which was introduced in the Brazilian Northeast in the 40's due to exhibit remarkable resistance to dry regions. It is believed that the invasive capacity of P. juliflora should be, partly, from the allelopathic activity of leaf tissues in vivo or decaying in the soil. The research objective was to evaluate the effect of incorporation of mesquite leaf residues to the soil on the germination and early growth of red rice (Oryza sativa L.), sesame (Sesamum indicum L.) and tomato (Lycopersicon esculentum Mill.). The experiments were conducted in a BOD chamber located in the Laboratory of Plant Ecology (12h light: 12h dark, at 25 °C), with a total duration of 14 days. To evaluate the allelopathic effect, were incorporated into the substrate (washed sand and soil in 1:1 ratio) in different concentrations of leaf residues dehydrated. The experimental design was a completely randomized design consisting of five concentrations (0g/kg, 5g/kg, 10g/kg, 15g/kg and 20g/kg of residues in the substrate) and 4 replicates of 25 seeds (experimental unit). In general, residues of P. juliflora incorporated into the soil proved to be no significant effects on most parameters evaluated for the species under study. Dose titration of the residue provided a better root development and an increase in dry matter production by the root (red rice), while influenced the increase in the size of the shoot, however, with decreased production of raw dried (tomato). For the sesame showed no significant effects for the parameters analyzed.