Industrial-scale composting process as a successful method for inactivation of potato cyst nematodes (Globodera spp. Skarbilovich) and sugar beet cyst nematode (Heterodera schachtii Schmidt)

Cyst producing nematodes are persistent soil-borne organisms causing severe damage to cultivated plants. Persistence of the economically relevant cyst nematode species Globodera pallida, G. rostochiensis and Heterodera schachtii was investigated at different stages during a large-scale industrial composting process to evaluate its efficiency to prevent spread of these nematodes into natural and agricultural habitats. Using reference cyst nematodes incorporated into organic waste from households and the processing industry, the effect of anaerobic fermentation and aerobic composting processes were investigated. Treated cysts were analysed for viability and reproductive potential by performing hatching tests and bioassays on susceptible host plants. The investigated composting plant showed temperatures between 40 and 72 °C at aerobic composting conditions depending on the sample position (bottom, middle, top) within the pile. We found no viable juveniles or reproductive potential of Globodera spp. (Loof and Bakker 1992) and less than 5 per cent reproduction of H. schachtii. Additionally to temperature conditions, we presume that competition of the microbial community and their released biodigestants like fatty acids also play a major role in successful treatment of these severe pest organisms.