Exsudação de ácidos orgânicos em rizosfera de plantas daninhas

In order to identify and quantify organic acids in the rizosphere of weeds infesting coffee plantations, the rizosphere samples of the weeds Bidens pilosa, Alternanthera ficoidea, Taraxacum officinale, Amaranthus deflexus were collected at the Experimental Farm of EPAMIG - Lavras-MG, Brazil. The samples were submitted to extraction and analyzed by High Performance Liquid Chromatography (HPLC). Oxalic, citric, acetic, butyric and propionic acids were identified in the rizosphere of the studied plants. The first two were found in larger concentrations and the largest concentrations occurred in B. pilosa.