Essential Oil of the Brazilian Native Species Hesperozygis ringens : A Potential Alternative to Control Weeds.

This study evaluated the allelopathic effect of theHesperozygis ringensessential oil using dicotyledonous and monocotyledonous seeds which are classified as weeds [Bidens pilosaandLolium multiflorum], bioindicators [Lactuca sativaandAvena strigosa] and crops [Glycine maxandOryza sativa]. The essential oil from the leaves was extracted and analyzed by gas chromatography coupled to mass spectrometry and gas chromatography with flame ionization detector. The extractive was diluted in ethanol, Tween 20 and water, and then tested at concentrations of 0.25, 0.50, 1.00, 2.50, and 5.00% (v/v). Water and the highest concentration of the solvents were used as control groups. The analyzed variables were germination, emergence velocity index, roots and shoot lengths and total seedlings length. Pulegone was the major essential oil compound representing 82.02% of the composition. Considering dicot seeds, the highest concentration of the extractive completely inhibited the germination ofBidens pilosawithout affecting the germination ofLactuca sativaandGlycine max. On monocots, the highest essential oil concentration affected the germination ofLolium multiflorumandAvena strigosawithout affecting theOryza sativaone. The results indicate that the extractive has the potential to control weeds because they were more affected than the crops. [ABSTRACT FROM PUBLISHER]