Hatching of Globodera pallida is inhibited by 2-propenyl isothiocyanate in vitro but not by incorporation of Brassica juncea tissue in soil

• Increasing exposure time of encysted Globodera pallida to 2-propenyl isothiocyanate in vitro resulted in a decrease in hatching.
• Hatch of G. pallida was similar after exposure to 2-propenyl isothiocyanate in either aqueous solution or headspace.
• Concentrations of the precursor of 2-propenyl isothiocyanate, 2-propenyl glucosinolate in Brassica juncea can be manipulated by sulfur fertilization and herbivory with Pieris brassicae.
• Incorporation of a realistic amount of B. juncea biomass into non-sterilised field soil does not decrease hatching of G. pallida in a pot experiment.

The aim of this study was to assess the feasibility of controlling the potato cyst nematode Globodera pallida through biofumigation with glucosinolate-rich Brassica juncea genotypes. The main glucosinolate of B. juncea is 2-propenyl glucosinolate which is the precursor of 2-propenyl isothiocyanate. Toxicity of 2-propenyl isothiocyanate to encysted G. pallida was tested in vitro. Fifty percent reduction in hatching was found within 2 h of exposure to 0.002% 2-propenyl isothiocyanate. Based on the in vitro results, we hypothesized that biofumigation with B. juncea would reduce hatching of G. pallidain vivo and higher 2-propenyl glucosinolate levels would have a stronger effect. Plant genotype, sulfur fertilization and insect herbivory affected 2-propenyl glucosinolate concentration of B. juncea. However, increasing 2-propenyl glucosinolate concentration of B. juncea did not affect G. pallida hatching after biofumigation. The absence of a biofumigation effect was most likely due to lower concentrations of 2-propenyl isothiocyanate in vivo compared to in vitro conditions. These results show that it is difficult to reach sufficiently high levels of toxicity to reduce hatching of G. pallida under realistic conditions.