16th IFOAM Organic World Modena, Italie

Like Brassicaeae spp, Allium spp present biofumigation properties which are attributed to sulphur components and mainly three disulfides: dimethyl disulfide (DMDS), dipropyl disulfide (DPDS) and diallyl disulfide (DADS) with a superior efficacy of DMDS. In this study, the biofumigant activity of Allium (onion and leek) by-products was investigated in vitro and in vivo. In vitro, the experimental model consists of a host-pathogen system: cucumber-Pythium ultimum. The results of the bioassay show that cucumber plants in compost inoculated with the pathogen and containing onion or leek by-products present a better vegetative growth compared to the control.

In vivo the soil biodesinfection with onion by-products in asparagus crops leads to an intermediate yield between the untreated soil modality and the methyl bromide treatment modality. An other aim of the present study was to produce more data about nematicid activity of disulfides. The activity of DMDS and DADS was evaluated on two nematods.