The biocidal properties of garlic, onion and leek are attributed to sulfur volatiles produced during degradation of Allium tissues. The primary emitted compounds are thiosulfinates ad zwiebelanes mainly converted in soil or in Allium products (extracts) to disulfides. The activities of these compounds were studied in vitro on soil pathogenic fungi and insects in order to measure their disinfection potential. These studies show a good potential for three disulfides: dimethyl disulfide (DMDS), dipropyl disulfide (DPDS) and diallyl disulfide (DADS) to inhibit several fungal species: Aphanomyces euteiches, Colletotrichum coccodes, Fusarium moniloform, Fusarium oxysporum radicis cucumerinum, Phytophtora cinnamomi, Pythium aphanidermatum, Rhizoctonia solani, Sclerotium rolfsii, and Sclerotinai sclerotiorum. The insecticidal activité of two disulfides was also evaluated on termites. The sensitivité varied with termite phenotypes and DMDS was the most toxic disulfide. This study shows that disulfides exhibit greater toxicity for insects than for fungi. These results confirm previous studies performed with the same compounds to determine insecticidal and nematicidal activities. This study is the basis of current field trials to test soil biofumigation with Allium cultures, Allium by-products and extracts.

• Dates
  Créé le 1 septembre 2004