Studies on the biology of potato cyst nematodes under Nordic conditions for improving management and regulation in Norway

The yellow potato cyst nematode (yPCN) Globodera rostochiensis and the white species (wPCN) G. pallida are quarantine pests subjected to national regulations. PCN infestations make production expensive and reduce the sales value of farms. Resistance break ing populations and long persistence of PCN in soil without host plants complicates control. Effective PCN management requires information on virulence, rate of decline in numbers and infectivity in soil, and information on conditions and practices increa sing decline rates. The current information, which comes from Central Europe and UK, is insufficient for Norwegian conditions. Today non-virulent yPCN is managed by crop rotation, while infestations by wPCN or virulent yPCN results in a 40-years ban on gr owing potato. In this project biotests will identify the pathotypes, and will be supported by morphological and molecular methods for species confirmation. Decline rates in the absence of host plants will be studied in selected fields. Studies will be con ducted on the occurrence and pathogenicity of microbial antagonists to PCN, and the use of molecular tools for their identification and quantification will be evaluated. The effect of early potato and Solanum sisymbriifolium as trap crops for PCN will be studied. Resistance test of selected potato cultivars on the Norwegian market will provide producers and advisers with updated information on PCN resistance. Studies on the host/parasite-relationship will identify vital components of the PCN-Potato pathos ystem. The results of this project will improve management systems. New information may allow for a shorter quarantine periods and make Norwegian potato production more efficient. Julius Kühn-Institut, Germany, Rothamsted research, UK, and Universidad Aut onoma de Madrid Spain will be important international collaborators. A reference group of farmers, advisers, industry and authorities will take part in discussions and evaluation of the progression of this project.