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Summary: The cyst nematode, Heterodera 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. [ABSTRACT FROM AUTHOR]

Background: This study showed, for the first time, the effect of volatile organic compounds (VOCs) emitted by castor bean cake added to soil on the plant‐parasitic nematode Meloidogyne incognita. Identification of nematotoxic volatiles increases the chance of identifying molecules for use in commercial nematicides. Results: VOCs produced after the incorporation of castor bean cake in the soil resulted in immobility (>97.3%) and death (>96.9%) of M. incognita second‐stage juveniles (J2) and reduction in M. incognita egg‐hatch (>74.3%) at all concentrations of cake tested (1.5–6.0%). A similar reduction in M. incognita infectivity and reproduction was observed when nematodes were exposed to these VOCs and inoculated into tomato plants or exposed directly upon contact with the soil. We identified 32 VOCs produced by castor bean cake when incorporated into soil by using solid phase micro‐extraction gas chromatography coupled with mass spectrometry (SPME‐GC‐MS). Four of the most intense peaks in the chromatogram represented the compounds phenol, 4‐methylphenol, γ‐decalactone, and skatole. When M. incognita J2 were exposed to these compounds, all of the compounds demonstrated nematicidal activity with low median lethal concentration (LC50) values. Conclusion: Castor bean cake incorporated into the soil produces volatile compounds which are toxic to M. incognita. These substances show potential for application in the nematicide‐producing industry. © 2018 Society of Chemical Industry Castor bean cake incorporated into the soil produces toxic volatiles to Meloidogyne incognita and four compounds show nematicidal activity against M. incognita. [ABSTRACT FROM AUTHOR]

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