Effect of 4-Ethylbenzaldehyde from the Volatilome of Annona muricata on Meloidogyne incognita

The demand for new soil fumigants has increased as a result of more restrictive legislation regarding the use of pesticides. In the present study, the potent nematicidal activity of volatile organic compounds released by the Annona muricata leaf macerate was demonstrated. In addition, we searched in the A. muricata volatilome for a molecule with potential to be developed as a new fumigant nematicide. In the greenhouse, even the lowest concentration of soursop leaf macerate tested (1.0%) as a biofumigant caused a significant (P < 0.05) reduction in Meloidogyne incognita infectivity and reproduction when compared with the nontreated control (0%). Forty-one compounds were identified through gas chromatography-mass spectrometry analysis, of which three (sabinene, caryophyllene oxide, and 4-ethylbenzaldehyde) were selected for studies against the nematode. Among these compounds, in in vitro trails, only 4-ethylbenzaldehyde showed nematicidal activity at 250 & mu;g ml(-1). The effective doses of 4-ethylbenzaldehyde predicted to kill 50 and 95% of the M. incognita second-stage juvenile population after 48 h of exposure were 35 and 88 & mu;g ml(-1), respectively. In in vitro tests, 4-ethylbenzaldehyde at 150 & mu;g ml(-1) reduced M. incognita egg hatching to values similar (P > 0.05) to those of the commercial nematicide fluensulfone at a concentration of 200 & mu;g ml(-1). In plant experiments, as a soil fumigant, 4-ethylbenzaldehyde at a dose of 1 ml/liter of substrate had an effect similar (P > 0.05) to that of the commercial fumigant Dazomet (250 & mu;g ml(-1)). Therefore, 4-ethylbenzaldehyde shows potential for development as a new nematicide.

Automated summary

The demand for new soil fumigants has increased due to stricter regulations on pesticide use. This study demonstrated the strong nematicidal activity of volatile organic compounds released by the Annona muricata leaf. 4-ethylbenzaldehyde shows potential as a new nematicide.