4-Ethylbenzaldehyde from the volatilome of Annona muricata against Meloidogyne incognita

Abstract

In the present study, we demonstrated the potent nematicidal activity of volatile organic compounds (VOCs) released by the Annona muricata leaf macerate. In addition, the toxicity of the compound 4-ethylbenzaldehyde was reported in the various phases of the Meloidogyne incognita life cycle. By biofumigation, even the lowest concentration of soursop leaf macerate tested (1.0%) caused a reduction in nematode hatching, infectivity and reproduction. Analysis of the soursop volatilome performed by gas chromatography coupled with mass spectrometry revealed 41 compounds, of which three, were selected for studies against the nematode. Only 4-ethylbenzaldehyde showed nematicidal activity in vitro, against M. incognita J2 and hatching. As a soil fumigant, 4-ethylbenzaldehyde at dose of 1 mL per litre of substrate had an effect similar (P < 0.05) to that of the commercial fumigant Dazomet (250 µg mL−1). In addition, this molecule, when applied directly to M. incognita-infested soil, significantly reduced nematode infectivity and reproduction compared to the negative control. Therefore, 4-ethylbenzaldehyde shows potential for the development of a new commercial nematicide with reduced toxicity to the environment and high efficacy against plant parasitic nematodes. However, field assays are necessary to confirm these results, which were obtained under controlled conditions.