Integrated management of Potato Cyst Nematode (Globodera Spp.) for more than half century in Norway

Integrated management of Potato Cyst Nematode (Globodera Spp.) for more than half century in Norway Potato cyst nematodes (PCN) Globodera spp. are thought to have originated in the Andean region of South America, and have been introduced into Europe after 1850. In the Nordic region PCN were detected in Sweden 1922, Denmark 1928, Finland 1946, Faroe Island 1951, Island 1953, and Norway 1955 (Videgård, 1969, Øydvin, 1978). Since its first record in Norway, PCN has been managed for more than 50 years. Initially extensive surveys were carried out and strict regulations prohibiting the introduction and spread of PCN with soil and plant materials were implemented. Early control strategies included the use of chemical fumigants and resistant potato cultivars in infested fields. Much emphasis was placed on documenting freedom from PCN in the certified seed potato production. The import and movement of all kinds of potato seed was prohibited, in order to prevent the introduction of new PCN populations, and nematode spread to uninfested land. Fields infested with PCN were placed under strict quarantine. In addition to this proper crop rotation involving resistant cultivars was enhanced (Øydvin, 1978). The taxonomic separation of the yellow Globodera rostochiensis and the white species G. pallida, and the emerging information on pathotypes changed the use of resistant cultivars to avoid the increase of resistant breaking populations. Chemical fumigants, organophosphates or carbamate nematicides have not been used in Norway since more than 40 years. Today, non-virulent G. rostochiensis is managed by crop rotation, while infestations by G. pallida or virulent G. rostochiensis results in 40-years ban on growing potato (Holgado & Magnusson, 2010; 2012). The use of non-host crops and alternating susceptible and resistant potato is important, but also complicated due to restricted acreage suitable for long rotations. The safe use of resistant cultivars requires knowledge on the species and pathotypes present (Holgado & Magnusson, 2010; 2012). In a recent project the identity of several populations from the main potato districts was studied using PCR amplification of ITS regions (Bulman & Marshall, 1997). Most populations were identified as G. rostochiensis, with the exception of one, which belonged to G. pallida. The PCR amplification and sequencing of the non-coding scmt mitochondrial region confirmed the species identification, and demonstrated a close relationship to common European populations. Studies on vap1 patterns demonstrated several variants of the vap-1 gene to be present in each population, and that differences in allele frequencies between populations are minor. References Bulman SR, Marshall JW, 1997. New Zealand Journal of Crop and Horticultural Science 25, 123-129. Holgado R, Magnusson C, 2010. Aspects of Applied Biology, 3rd Symposium on Potato Cyst Nematodes 103:87-92. Holgado R, Magnusson C, 2012. Potato Research 55, 269-278. Videgård G, 1969. Potatis 1969, 26–28. Øydvin J, 1978. Växtskyddsrapporter Avhandlingar 2, 1–37.