Oospores of Phytophthora infestans in soil provide an important new source of primary inoculum in Finland

There have been numerous indications since the 1990s that oospore-derived primary infections play an increasing role in the epidemiology of potato late blight. The aim of this study was to verify that oosporederived epidemics actually occur in Finland. For this purpose, 20 suspected foci of oospore-derived potato late blight were scouted in 2000–2002. All of these were located in fi elds in which late blight had been observed in at least one of the four previous years. Primary symptoms in these foci occurred always on the lowest leaves near or touching the ground. Leafl ets typically showing numerous primary infections or lesions were in direct contact with the soil. In the former, oospores were observed after incubation. Soil samples from two experimental fi elds, marked by severe epidemics in most years during the last decade, caused infections in a bioassay. Both mating types were on every occasion present in groups of single lesion isolates collected from foci and the bioassay. Oospores survived over the winter, as shown by soil samples taken during the spring that infected potato leafl ets in the bioassay. The results presented indicate that oospore-derived epidemics occur in Finland. This paper also discusses the role of oospores in causing blight epidemics in Finland compared to more southern countries

Potato late blight - fatal threat in organic potato production

Improved potato late blight management is crucial for the continuity of organic potato production. Two major changes in cultural practises are necessary: more diverse crop rotation with at least 4 years between consecutive potato crops and optimising nitrogen fertilisation according to the needs of the crop

Examples of alien pathogens in Finnish potato production - their introduction, establishment and consequences

Most pathogens on potato have been imported into Finland via contaminated seed more than hundred years ago. The history of migration and the consequences for potato production of potato wart, blackleg and soft rot, Potato mop-top virus (PMTV) and its vector powdery scab are reviewed as examples of economically important and biologically different potato pathogens. Potato wart spread alarmingly during 1920-1960. Plant quarantine acts and the use of resistant cultivars were successful in eradicating the disease. The pathogens causing blackleg and soft rot increased rapidly in 1960-1970. Development of seed certification schemes after the end of the 1970s decreased disease incidence and made the disease insignificant other than for seed potato production. Introduction of new strains of blackleg bacteria in 2003 caused the disease again to become a considerable threat to potato production. PMTV was imported into Finland in the 1970s where it spread rapidly, especially in starch potato production. Currently it is common in all potato production except that of seed potato. The disease cannot be eradicated but contamination of clean fields can be prevented. New diseases can spread to Finland in future but population changes of existing pathogens have recently caused more problems than species completely new to Finland

Oospore biology in the Nordic countries: Facts, hypothesis and anecdotes

The migration of the A2 mating type of Phytophthora infestans and new blight populations into Europe in 1980s raised serious questions: Are oospores formed in the potato crop? Can they survive in soil? Can they infect following potato crops? What is their impact on late blight epidemiology

Uudet menetelmät paljastavat perunan piilevän tyvimädän

MTT:n (Maa- ja elintarviketalouden tutkimuskeskus) tutkimushankkeessa on kehitetty menetelmiä, joilla voidaan luotettavasti todeta perunan mukuloista piilevä tyvi- ja märkämätä. Tutkimustulokset antavat pohjan massatestauksiin soveltuville menetelmille, jotka palvelevat koko perunatuotannon ketjua.vo

New and old pathogens of potato in changing climate : Proceedings of the EAPR Pathology Section seminar, 2.-6th of July 2007, Hattula, Finland

Euroopan Perunatutkijoiden Yhdistys (EAPR, The European Association for Potato Research) on vuonna 1957 perustettu järjestö, johon kuuluu perunatutkijoita ja tutkimuksesta kiinnostuneita alan toimijoita. Yhdistyksen kotisivu löytyy linkistä http://www.eapr.net. Yhdistys kustantaa Potato Research nimistä tieteellistä aikakausilehteä, jossa julkaistaan perunaan liittyviä tutkimustuloksia, kokooma-artikkeleita ja muita yleistä kiinnostusta herättäviä kirjoituksia. EAPR:n tärkein tiedonvaihto on alusta saakka tapahtunut tieteenalapohjaisissa jaostoissa. Yhdistyksessä on seitsemän jaostoa: Perunanviljely, jalostus ja lajikkeet, tekniikka, patologia, fysiologia, käyttölaatu ja virologia. Jaostot kokoontuvat säännöllisesti tutkimusongelmien ja -tulosten merkeissä. Edellinen patologiajaoston seminaari oli Lillessä, Ranskassa vuonna 2004. Edellisessä patologiajaoston kokouksessa Bilbaossa, Espanjassa kesällä 2005 jaoston puheenjohtaja tri Jozefa Kapsa valtuutettiin järjestämään seuraava seminaari Suomessa. Asko Hannukkala lupautui vastaamaan seminaarin käytännön järjestelyistä. Seminaarin teemaksi valittiin "Uudet ja vanhat perunan taudit muuttuvassa ilmastossa", koska Euroopan perunaruttopopulaation muutoksista on viime vuosina julkaistu paljon uutta tutkimustietoa. Myös aiemmin Euroopassa harvinaiset taudinaiheuttajat, kuten Erwinia chrysanthemi, ovat aivan viime vuosina yleistyneet hälyttävästi pohjoisillakin viljelyalueilla. Ilmastonmuutoksen vaikutusten arviointi sopii erityisen hyvin Suomessa käsiteltäväksi aiheeksi, koska ennustettu ilmaston lämpeneminen suosii monia kasvintuhoojia, joita ei vielä esiinny pohjoisessa ilmastossa. Suomen Akatemian myöntämä avustus kokouksen järjestämiseen on mahdollistanut useiden kansainvälisten asiantuntijoiden kutsumisen luennoimaan seminaarissa. MTT Maa- ja Elintarviketalouden tutkimuskeskus ja monet peruna-alan yritykset ovat antaneet seminaarin järjestelytoimikunnalle merkittävästi henkistä ja aineellista tukea.The European Association for Potato Research (EAPR) is an organization, formally constituted in 1957, consisting of people working in, or with an interest in, potato research, http://www.eapr.net. The Association publishes a journal Potato Research , which includes original scientific contributions on both fundamental and applied research on potatoes, review articles and topics of general interest. Over the intervening period since the founding of EAPR the Association has been very much enhanced by the activities of the Sections which have performed the invaluable function of promoting the interchange of knowledge within specific disciplines. The Association has seven sections: agronomy, breeding and varietal assessment, engineering, pathology, physiology, utilization, and virology. The sections meet regularly to discuss problems and research results. The previous Pathology Section meeting was organized in Lille, France in 2004. At the latest Pathology section meeting in Bilbao, Spain in 2005 the chair person of the section, Dr. Jozefa Kapsa, was authorized to organize the next seminar and meeting in Finland in collaboration with the local organizer Asko Hannukkala. The theme of the seminar New and old pathogens of potato in changing climate was chosen, because changes in the populations of potato late-blight pathogen have been reported throughout Europe and elsewhere. Also, pathogens such as Erwinia chrysanthemi, previously rare in Europe have recently spread into Northern potato production regions. Speculation on the effects of climate change to potato diseases is especially appropriate in Finland, where the predicted climate warming favours many pests not currently present in a cool climate. Support granted by the Academy of Finland made it possible to invite several international experts on potato pathology as key-note speakers to the seminar. MTT, Agrifood Research Finland as well as companies in the potato sector have given extensive support to the organizing team.vokMyynti MTT Tietopalvelut 31600 Jokioine