Control of Globodera pallida, a major pest of potato, usually relies on rotation and chemical nematicides, but two formerly widely applied nematicides, aldicarb and 1,3-dichloropropene, have now been withdrawn from use within the European Union (EU) (European Council Directive 91/414/EEC). Further EU restrictions (EC 1107/2009) could result in the withdrawal of some or all of the remaining approved nematicides, ethoprophos, fosthiazate, and oxamyl. The development of alternative methods to replace withdrawn nematicides is therefore a matter of priority for the EU potato industry and may benefit growers and consumers worldwide.
One potential approach is biofumigation, the suppression of soilborne pests and pathogens by incorporation of brassica green manures into soil. Field experiments have demonstrated the ability of this approach to control plant-parasitic nematodes in certain cropping systems, including Meloidogyne javanica in vineyards and Meloidogyne incognita in courgette production. However, the level of pest or pathogen suppression achieved with brassica green manures varies. In some cases, biofumigation has provided moderate to high levels of control, but in other cases it has had little effect on target organisms.
Work in the lab has identified and characterised several brassicas with a high level of effectivness controlling G. pallida in the soil and identified improved methods for applying biofumigants to soil.