Nematicidal activity of ethanol solutions on soybean cyst nematode Heterodera glycines

The cyst nematode, Heierodera glycines, is a major pathogen of soybean in tropical regions, which demands novel sustainable management practices. In this work, the use of ethanol against H. glycines was evaluated as both a solution and a fumigant. On second-stage juveniles (J2) of H. glycines, ethanol at low concentration was more effective by direct dipping than by only fumigating the J2. Hatching was significantly reduced by direct dipping in ethanol solutions. Fumigation of H. glycines-infested soil with ethanol reduced infectivity by almost 100% and the number of eggs by about 67% at ethanol concentrations of 48% and 72%, respectively. Only the ethanol at 48% concentration significantly reduced the J2 lipid content, while J2 infectivity and the number of eggs were reduced by dipping at 6% ethanol. The J2 were internally altered by the ethanol solutions. Therefore, ethanol is toxic to H. glycines at low concentrations and affects its pathogenic behaviour rather than simply reducing the lipids.