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Free-living plant-parasitic nematodes (free-living PPN) appear to be an increasing problem in Norwegian agriculture and their efficient management is required. Methods of efficient nematode management have been sought for personnel involved in farmer’s advisory and among farmers. In order to clarify the nematode situation in different agricultural crops a pilot project for surveying free-living PPN was conducted during the growing seasons 2016 and 2017. The Norwegian Agricultural Extension Service were involved in selecting major crops and selected representative areas for sampling. Complementary to the survey was that the samples should be collected form crops showing symptoms of nematode damage. Nematode damage occurs where large populations of nematoder are present in fields and shows as patches of poor plant growth........

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Bruk av husdyrgjødsel er stadig mer brukt til å produsere biogass. Rester (bio- avfall) etter biogass prosesser, kan bli bruk som gjødsel. Hvis ugressfrø, plante patogener og nematoder overlever anaerob prosessen, bruk av bioavfall kan bli en fytosanitær risiko. Litteratur om effektene av mesofil temperatur spesielt på (to) ugress (en) plantepatogen og potetcystnematode-levedyktighet ble gjennomgått. Ifølge den tilgjengelige litteraturen må det konkluderes at behandlinger som vanligvis brukes i mesofil prosess ikke vil være tilstrekkelige for fullstendig inaktivering av plantepatogener. Dette refererer til patogener av potet som er oppført i norsk regulering (Matloven) og EU-direktiv 2000/29 / EF, spesielt Synchytrium endobioticum.

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El frijol común (Phaseolus vulgaris L.) constituye un valioso alimento para la población de Latinoamérica; entre las numerosas plagas que lo afectan en la región están los nematodos parásitos de plantas (NPP) o fitonematodos. Los objetivos de este trabajo fueron analizar y resumir la información disponible acerca de las relaciones nematodos parásitos de plantas (NPP) - P. vulgaris en América Latina, profundizando en los avances, problemas y perspectivas del tema en Cuba, como un aporte a la preparación del personal vinculado a la producción y al manejo de nematodos en los frijoles que se producen para ser consumidos como grano seco. Se analizó la información contenida en las bases de datos SciELO, Sciencedirect y otros repositorios, donde se constató que en la región parasitan el frijol Meloidogyne arenaria (Neal) Chitwood, Meloidogyne decalineata Whitehead, Meloidogyne ethiopica Whitehead (syn. jun. Meloidogyne brasiliensis), Meloidogyne hapla Chitwood, Meloidogyne incognita (Kofoid y White) Chitwood, Meloidogyne inornata Lordello, Meloidogyne javanica (Treub) Chitwood, Meloidogyne luci Carneiro et al., Meloidogyne phaseoli Charchar et al. y Meloidogyne spp., Aphelenchoides besseyi Christie, Nacobbus aberrans (Thorne) Thorne y Allen y Pratylenchus spp. En los estudios recibieron la mayor atención los aspectos relacionados con la evaluación de cultivares y otras tácticas como la preparación del suelo, el intercalamiento y el uso de agentes biológicos. La información analizada indicó que más de 45 genotipos de frijol mostraron algún nivel de resistencia a Meloidogyne spp. (nematodos agalleros), sobresaliendo el cultivar Aporé en estudios en Brasil y Triunfo-70 en Cuba, lo que revela la existencia de materiales promisorios para programas de mejoramiento del frijol que se ejecutan en esos países. La importancia estratégica de este cultivo para Cuba, considerado como prioritario para la seguridad alimentaria, impone la necesidad de profundizar en los estudios de la interacción NPP-P. vulgaris, como elemento básico para el adecuado manejo del cultivo.

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El objetivo del estudio fue determinar el factor de reproducción (FR) de Meloidogyne incognita (Kofoid y White) Chitwood y el efecto nocivo del nematodo sobre parámetros seleccionados del desarrollo de las plantas de frijol (Phaseolus vulgaris L.) cultivar ‛Cuba Cueto 25-9’. El experimento se realizó, en condiciones semicontroladas, durante 35 días, con niveles poblacionales iniciales (Pi) de 1,5; 2,5 y 5 juveniles de segundo estadio (J2) y huevos del nematodo por gramo de sustrato y plantas de frijol sin nematodos (testigos). Se determinó el Factor de Reproducción (FR) del nematodo y en la planta se evaluaron el Índice de Agallamiento (IA), la altura de las plantas, el diámetro del tallo, el número de hojas, flores y legumbres. Los datos se analizaron y compararon (ANOVA, Duncan (p<0,05)) y la relación entre la altura de las plantas y Pi se determinó a través de análisis de regresión, empleando el Paquete Estadístico SAS, Versión 9.0. El nematodo parasitó y se reprodujo en el cultivar de frijol ‛CC- 25-9’ con valores de FR=1,6; 6,1 y 6,2 y del IA=3; 3,6 y 3,8 en los niveles de Pi=1,5; 2,5 y 5 J2-huevos x gramo de sustrato-1, respectivamente. Con el incremento de la Pi del nematodo se redujo, significativamente, la altura de las plantas del cultivar ‛CC 25-9’ (R2=0.70). El nematodo produjo disminuciones, no significativas, del diámetro del tallo, número de hojas, flores y legumbres; sin embargo, se evidenció una tendencia a que los mayores valores de los parámetros evaluados se presentaron en las plantas sanas. Se discute la importancia de utilizar plantas de la misma familia al momento de evaluar resistencia/susceptibilidad de cultivares frente a Meloidogyne spp.

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Kartleggingsprogrammet for 2016 startet i april og sluttet 31. desember 2016. Programmet omfattet potetprodusenter som hadde dyrket poteter i 2015 og søkt om produksjonstilskudd for slik produksjon. Prøveuttaket foregikk delvis i felt hvor det var dyrket poteter i 2015. I tillegg ble det tatt prøver fra sorteringsjord i mottaksvirksomheter. I 2016 det ble undersøkt totalt 34 jordprøver i programmet. Kartleggingsprogrammet omfattet fylkene Møre og Romsdal (22 jordprøver fra mottaksvirksomheter), Nordland (10 jordprøver fra felt), Troms (2 jordprøver fra felt). Det ble ikke funnet PCN i prøvene fra Møre og Romsdal, Nordland og Troms. I kartleggings program for 2014, 2015 og 2016 det ble ikke funnet PCN i prøvene fra Norland, Troms og Finnmark fylkene. Dette viser at Nordland Troms og Finnmark fylkene er så langt fri for potetcystenematoder, og dette antyder at PCN ikke finnes i nordlige områder med potet produksjon. Fra 2009 til 2016 ble det analysert 18846 jordprøver, (13951 fra felt, og 4895 fra mottaksvirksomheter), i 17817 prøver PCN ble ikke funnet. Potetcystenematoder ble funnet i 995 jordprøver som representerer 5,2 % av totalet. I kartleggingsprogrammet for 2009 - 2016 hvit PCN (Globodera pallida) ble funnet i 92 prøver. I disse 92 prøver, blanding av G. rostochiensis og G.pallida ble funnet i 73 prøver. Dette kan indikere at tiltak som er satt i verk for å begrense spredningen har hatt effekt. Siden 1955 lovregulering for PCN har som målsetning å hindre introduksjon og spredning av PCN med jord og plantemateriale, samt å sikre et kontrollert bruk av resistente potetsorter for å unngå resistensbryting. PCN-Forskriftene har også gjort det mulig å unngå bruken av kjemiske fumiganter, organofosfater eller karbamater (nematicider). Nematicider har ikke vært brukt i potetproduksjon i Norge

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Few studies have reported findings on the use of Pochonia chlamydosporia for the management of plant-parasitic nematodes under field conditions. In this chapter we describe experiences of P. chlamydosporia application in temperate crops grown in the UK, Norway and Poland. To date, the fungus has been recovered from different endoparasitic nematodes from a range of locations across Europe. Pochonia chlamydosporia is an egg parasite as well as a saprophyte and plant endophyte and is primarily applied as a biological control agent to reduce nematode multiplication. In the UK, several field and micro-plot experiments have demonstrated that the fungus is capable of causing ca 50% reductions in the multiplication of Globodera pallida in potatoes. Further work was undertaken to evaluate the compatibility between P. chlamydosporia applications and the fungicide azoxystrobin which is used for managing the soil borne fungus Rhizoctonia solani. Although P. chlamydosporia is sensitive to azoxystrobin, there is evidence to suggest that it may not affect its efficacy as a biological control agent. In Norway, the fungus has been isolated from various cyst nematodes (Heterodera spp. and Globodera spp.), however, under in vitro conditions it was found to lose pathogenicity. Work undertaken in Poland has shown that strains of P. chlamydosporia can reduce populations of H. schachtii in sugar beet. Sugar beet grown in a 3 year rotation in combination with a mustard green manure increased egg parasitism by P. chlamydosporia in comparison to other treatments which included the addition of straw or manure. Further work is discussed on the ability of strains of P. chlamydosporia to parasitize eggs of Meloidogyne incognita, M. hapla and M. arenaria at a range of temperatures.

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El objetivo de este trabajo fue determinar los métodos más efecientes para la extracción de las comunidades de nematodos presentes en suelos del agrupamiento Ferralíco. Se muestrearon las localidades de Güines y San José de las Lajas, en la provincia Mayabeque, Cuba. El área seleccionada de 1 ha de suelo, se dividió en estratos y de cada uno se tomaron 100 submuestras para conformar cuatro muestras por ha. La toma de muestras se realizó en zig-zag utilizando una barrena; se colocaron en una bolsa de polietileno y se trasladaron al laboratorio de Nematología Agrícola del Centro Nacional de Sanidad Agropecuaria (CENSA).Se utilizaron lastécnicas de Embudos de Baermann, Bandejas Whitehead modificadas (en ambas con filtros de leche y gasa), así como el método de las dos botellas y la técnica de centrifugación flotación. Se procesaron 5, 25, 50, 100, 150, 250 y 350 gramos de suelo, excepto en la técnica de Embudos Barmann, donde se utilizaron 5 y 25g. Los datos del número de especímenes extraídos por muestra se procesaron mediante Análisis de Componentes Principales. Los mayores recobrados se obtuvieron con los métodos de las Bandejas de Whitehead (con ambos filtros)(100g de suelo) y el método de Centrifugación-Flotación

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Con el objetivo de conocer el comportamiento resistente/susceptible a Meloidogyne incognita (Kofoid y White) Chitwood de los cultivares de frijol común (Phaseolus vulgaris L.) BAT-306 y Triunfo-70, se efectuó este estudio en condiciones semicontroladas en la provincia Mayabeque, Cuba. Se utilizaron macetas con 1kg de sustrato y las plantas se inocularon con una serie geométrica de seis densidades poblacionales iniciales del nematodo (población aislada originalmente de frijol) (Pi) (0,125; 0,25; 1; 4; 16 y 64 huevos y juveniles de segundo estadio (J2) por gramo de sustrato-1); a los 60 días se determinó la Población Final (Pf) y se calculó el Factor de Reproducción. El cultivar Triunfo-70 se comportó como resistente en presencia de Pi < 64 huevos - J2 por gramo de sustrato-1, con FR = 0,23 - 0,9; sin embargo, BAT-306 permitió la reproducción del nematodo con FR entre 6,1 y 8. Los cultivares BAT-306 y Triunfo-70 pudieran utilizarse en estudios de cultivares de frijol frente a poblaciones cubanas de M. incognita, como testigos susceptible y resistente, respectivamente.

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The root-knot nematode Meloidogyne graminicola is a major constraint in rice production in the world. Using rDNA-ITS sequences data alignments, the genetic variation among twenty-one populations of M. graminicola (sixteen from Myanmar and five from China) was investigated. The results showed that all the populations were clearly separated from other species and that there was a low level of genetic variation among the isolates. A set of species-specific primers was designed to develop a species-specific molecular tool for the precise identification of M. graminicola. The primer reliability, specificity and sensitivity tests showed that the primer set (Mg-F3 and Mg-R2) amplified the expected fragment size of 369 bp from the template DNA of target nematode populations but not from non-target organisms. A duplex PCR test allows for saving diagnostic time and costs by amplifying the species of interest from a nematode mixture. Therefore, this species-specific primer set may be a powerful tool to improve taxonomic identification by non-specialists and the design of successful management practices as well.

Sammendrag

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.

Sammendrag

Nematodes as limiting factors in potato production in Norway Plant parasitic nematodes associated with potato feeds on roots and/or tubers. At least 68 species, representing 24 genera of have been found associated with potato. Since nematodes generally attack underground plant parts, there are no reliable foliar symptoms to show that nematodes may be the major cause of poor growth and reduced tuber yields. Potato roots damaged by nematodes may show the presence of lesions, females/cysts or galls. After a few weeks, however, roots may be attacked by other pathogens such as bacteria and fungi, and the original damage by nematodes may not be obvious. Therefore, nematode damage often may have been attributed to other factors. There are no estimations for potatoes yield losses in Scandinavia due to nematodes, however, in the United Kingdom, it is estimated that 9 % of the potato crop is lost annually because of the potato cyst nematodes (PCN), Globodera rostochiensis and G. pallida, and it is reasonable to assume that this percentage is also applicable to Scandinavia. However, if we consider the possible additional effects of other nematode species occurring in Norway, yield reductions could be as high as 20%. Besides direct yield losses, some nematodes affect tuber quality. Yield losses depend on the pathogenicity of the species of nematode, the nematode population density at planting, the susceptibility and tolerance of the host and by a range of environmental factors. In Norway, potato cyst nematodes (G. rostochiensis and G. pallida) are by far the most important nematodes in potato. Other important nematodes include root-lesion nematodes (Pratylenchus spp.), stubby root nematodes (Trichodorus spp. and Paratrichodorus spp.) and stem and tuber nematodes (Ditylenchus spp.). Nematodes considered less important include root knot nematode (Meloidogyne hapla) and needle nematodes (Longidorus spp.). In Norway, potato cyst nematodes (Globodera rostochiensis and G. pallida) are quarantine pests subjected to regulations. PCN infestations result in costly production systems and loss in sales value of farms. Their occurrences restrict acreage available for potato production as in some cases legislative regulations forbid potato production or make the production more difficult and more expensive. Furthermore societal consequences by far exceed yield losses. It is also compulsory to sample the soil for seed potato production to document freedom from PCN. When PCN is present in the field complete eradication is not possible. Effective management requires reliable information on virulence, decline rates of population densities and infectivity in soil. It is also crucial to know what conditions or practices increase these decline rates. Today in Norway, non-virulent G. rostochiensis is managed by crop rotation, while infestations by G. pallida or virulent G. rostochiensis pathotypes capable of breaking the resistance in potato cultivars in current use results in a 40-years prohibition for growing potato in the infected field. Root-lesion nematodes (Pratylenchus spp.) cause damage to the roots and induce scabby to sunken lesions on tubers. Stubby root nematodes (Trichodorus spp. and Paratrichodorus are nematode vectors of Tobacco Rattle Virus they causes the symptom called “Spraing” in tubers. Occasionally stem and tuber nematodes (Ditylenchus spp.), have been reported as problems both in field and storage, especially when weeds are not well controlled. Management strategies aim to prevent nematode multiplication and hence protect the potato crop from damage. An efficient method of controlling nematodes as Ditylenchus spp. and root-lesion nematodes is black fallow, but this may be difficult to achieve in many cases.

Sammendrag

Plant parasitic nematodes associated with potato feed on roots and/or tubers. About 70 species, representing 24 genera, have been reported from potato. Since nematodes attack underground plant parts, there are no reliable foliar symptoms to show that nematodes may be the major cause of poor growth and reduced tuber yields. Potato roots damaged by nematodes may show lesions, abnormal proliferation of lateral roots, emerging white females and brown cysts. Nematode attacks may render plants vulnerable to other pathogens, so disease caused by microorganisms may have nematodes as an etiological component. Therefore, nematode damage may often have been attributed to other factors. In Scandinavia, potato cyst nematodes (Globodera rostochiensis and Globodera pallida) are by far the most important nematodes on potato. In Norway, the cost of compensations schemes due to imposed statutory regulations of potato cyst nematodes may some years exceed the compensation for any other pests or diseases organism in agriculture. Other important nematodes include root lesion nematodes (Pratylenchus spp.), stubby root nematodes (Trichodorus spp. and Paratrichodorus spp.), and potato rot and stem nematodes (Ditylenchus spp.). Root knot nematode Meloidogyne hapla is considered less important. Meloidogyne chitwoodi and Meloidogyne fallax are not known to be present in Nordic countries. In the control, crop rotations using non-host crops, alternating susceptible and resistant potato cultivars, are an important control measure. However, the use of resistant potato cultivars requires knowledge of the species and pathotypes present in the field.

Sammendrag

A survey of the prevalence of skin blemish diseases in potatoes after the growing seasons of 2008 and 2009 was carried out on 247 potato lots representing different cultivars and production regions in Norway. The results showed the presence of silver scurf (Helminthosporium solani) in all lots. Skin spot (Polyscytalum pustulans) and black scurf (Rhizoctonia solani) were found in 80% of the lots, and black dot (Colletotrichum coccodes) and common scab caused by Streptomyces spp. were present in 50–70%. Also, powdery scab (Spongospora subterranea) occurred in 65–80% of the lots, and root-lesion nematodes (Pratylenchus spp.) were detected in 60% of the sub-samples that exhibited symptoms of common scab.

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In 1955 the potato cyst nematode was recorded for the first time in Agder. This detection produced the initial legislation of PCN control, and was implemented based on the statutory regulation of 1916. Since 1956 PCN was given quarantine status in infested agricultural land and home gardens. Official controls of certified seed potatoes started in 1939. Each year about 3000 soil samples are analyzed for PCN to clear areas for certified seed potato production.  These areas are so far free of PCN. The total acreage with seed potatoes in 2009 was 813.7 Ha. Extensive surveys started in 1955; and were carried uninterrupted until the end of the 1990ties. These surveys included producing potato agricultural land and home gardens. In 2009 a new national survey program for the principal potato districts has started, the surveys is aimed to update the PCN occurrence. The surveys will continue during the subsequently years until all major potato areas will be cover.  Statutory regulations for PCN from 1956-2010 to Support to Norwegian Food Safety Authority The regulations have without doubt contributed in preventing PCN infestations in the seed potato areas, and probably also prevented further spreading of wPCN and virulent yPCN as each the find has been placed under quarantine. Permanent grass as a statutory regulation in home garden plots may have contributed to reduce the spread of wPCN to commercial fields. The regulations have most probably made possible the early reduction in use of chemical fumigants, organophosphates or carbamate nematicides.  These chemicals have not been used since the early 1970s. The domestic production of seed potato has been kept free of PCN by frequent inspections and analyses for more than 50 years. The fact that farmers are not allowed to import seed potatoes adds to the level of security. New project Studies on the biology of potato cyst nematodes (Globodera spp.) under Nordic conditions for improving management and regulation in Norway. To increase the scientific basis for amending the management system for PCN, Globodera spp under Nordic conditions.

Sammendrag

In 1955 the potato cyst nematode was recorded for the first time in Agder. This detection produced the initial legislation of PCN control, and was implemented based on the statutory regulation of 1916. Since 1956 PCN was given quarantine status in infested agricultural land and home gardens. Official controls of certified seed potatoes started in 1939. Each year about 3000 soil samples are analyzed for PCN to clear areas for certified seed potato production.  These areas are so far free of PCN. The total acreage with seed potatoes in 2009 was 813.7 Ha. Extensive surveys started in 1955; and were carried uninterrupted until the end of the 1990ties. These surveys included producing potato agricultural land and home gardens. In 2009 a new national survey program for the principal potato districts has started, the surveys is aimed to update the PCN occurrence. The surveys will continue during the subsequently years until all major potato areas will be cover.  Statutory regulations for PCN from 1956-2010 to Support to Norwegian Food Safety Authority The regulations have without doubt contributed in preventing PCN infestations in the seed potato areas, and probably also prevented further spreading of wPCN and virulent yPCN as each the find has been placed under quarantine. Permanent grass as a statutory regulation in home garden plots may have contributed to reduce the spread of wPCN to commercial fields. The regulations have most probably made possible the early reduction in use of chemical fumigants, organophosphates or carbamate nematicides.  These chemicals have not been used since the early 1970s. The domestic production of seed potato has been kept free of PCN by frequent inspections and analyses for more than 50 years. The fact that farmers are not allowed to import seed potatoes adds to the level of security. New project Studies on the biology of potato cyst nematodes (Globodera spp.) under Nordic conditions for improving management and regulation in Norway. Major goal is to increase the scientific basis for amending the management system for PCN, Globodera spp under Nordic conditions.

Sammendrag

In Norway PCN was recorded in 1955. This resulted in extensive surveys and implementation of statutory rules. Regular surveys until the 1990s revealed PCN to occur in 6406 properties. The first statutory regulation for PCN appeared in 1956, and prohibited the introduction and spread of PCN with soil and plant materials. Before the early 1970:ties control strategies included the use of nematicides (fumigants, organophosphates and carbamate) and resistant potato cultivars. The distribution of species and pathotypes is of crucial importance for mangement. The yellow species Globodera rostochiensis (yPCN) occurs in the pathotypes Ro1, Ro2, and Ro3, while the white species G. pallida (wPCN) has been detected in the pathotypes Pa1, Pa2 and Pa3. The most common pathotype Ro1 constitutes 98% of total finds. Recently the detections of wPCN and yPCN Ro3 in ware potato fields have increased. Today non-virulent G. rostochiensis is managed with crop rotations using non-host crops and alternating susceptible and resistant potato. The use of certified seed potato is important. Detection of G. pallida or virulent G. rostochiensis results in statutory regulation (at least 40-years ban on growing potato). Generally Norwegian potato cultivars have the resistance gen, Gro-1 (H1) from Solanum tuberosum ssp. andigena. In Norway great emphasis has been placed on documenting freedom of PCN in areas for certified seed potatoes. In 2009 a national survey of ware potato land was initiated. The use of early potato and Solanum sisymbriifolium as trap crops, and the significance of micro-organisms antagonistic to PCN are considered in current research. Norwegian regulations have prevented PCN infestations in the seed potato areas, and reduced spread of wPCN and virulent yPCN. A better prognosis of rates of decline in PCN numbers and infectivity in fields could allow for a reduction in the quarantine period and improve the economy of farmers and enterprises.

Sammendrag

Cyst nematodes, Heterodera spp. are known world-wide as parasites of cereals and grasses.  Norwegian surveys have revealed that nematodes belonging to the H. avenae complex occur throughout the country; our studies have combined morphology, protein variability (IEF), bio-tests and internal transcribed spacers (ITS3 and ITS5) for the identification of Heterodera populations. Our results showed some divergences between techniques in species identity of some of the studied populations H. avenae is the most common species followed by H. filipjevi (Holgado et al., 2009).. Several populations of H. filipjevi west did not reproduce in oat differentials. In this case both the morphology and protein patterns rather indicated these populations to belong to H. pratensis. In this study a population from Brekstad differed from all other populations in its morphology, and the protein pattern was close to H. mani. This population was collected from barley, and in the pathotype test it was virulent on several barley cultivars. Mathews, 1971reported that H. mani did not reproduce on cereals while (Cook, 1982) indicates that some barley cultivars can serve as hosts. Surprisingly the ITS studies indicated the Brekstad population to be close to H. avenae. This population is in many ways strikingly different from H. avenae, and this result may indicate a need to revise the present gene library of H. avenae. It also demonstrates the need for using several techniques in species identification. In our study the least degree of divergent results on nematode identity is between morphology and IEF.

Sammendrag

Cyst nematodes, Heterodera spp. are known world-wide as parasites of cereals and grasses.  Norwegian surveys have revealed that nematodes belonging to the H. avenae complex occur throughout the country; our studies have combined morphology, protein variability (IEF), bio-tests and internal transcribed spacers (ITS3 and ITS5) for the identification of Heterodera populations. Our results showed some divergences between techniques in species identity of some of the studied populations H. avenae is the most common species followed by H. filipjevi (Holgado et al., 2009).. Several populations of H. filipjevi west did not reproduce in oat differentials. In this case both the morphology and protein patterns rather indicated these populations to belong to H. pratensis. In this study a population from Brekstad differed from all other populations in its morphology, and the protein pattern was close to H. mani. This population was collected from barley, and in the pathotype test it was virulent on several barley cultivars. Mathews, 1971reported that H. mani did not reproduce on cereals while (Cook, 1982) indicates that some barley cultivars can serve as hosts. Surprisingly the ITS studies indicated the Brekstad population to be close to H. avenae. This population is in many ways strikingly different from H. avenae, and this result may indicate a need to revise the present gene library of H. avenae. It also demonstrates the need for using several techniques in species identification. In our study the least degree of divergent results on nematode identity is between morphology and IEF.

Sammendrag

Nematodes, commonly known as round worms, are the most common multicellular animals on planet Earth. After 1000 million years of evolution members of the phylum Nematoda have a high bionomic diversity. As habitants of the soil and rhizosphere nematodes are involved en energy fluxes, and affect carbon and nutrient cycles. As plant parasites, either alone or in synergism with other pathogens, nematodes are responsible for plant disease complexes and major crop losses. A growth depression in a field of potato (Solanum tuberosum) cv. Saturna [resistant to pathotype Ro1 of potato cyst nematode (PCN) Globodera rostochiensis], suggestive of potato cyst nematode damage, was detected in Grue, eastern Norway. Analyses of soil samples did not detect PCN, but demonstrated the occurrence of a large number of lesion nematodes Pratylenchus penetrans .Tubers from the depressed part of the field had severe symptoms similar to those caused by the common scab bacterium Streptomyces scabies. Potato yield was reduced by 50% in the affected area of the field. Transect-sampling showed plant growth to be negatively correlated with densities of P. penetrans and suggested a damage threshold of potato to the nematode of 100 specimens per250 g of soil. Common scab (Streptomyces scabies) occurred frequently in the affected area. P. penetrans was present in roots, underground stems, stolons and tubers. Tubers from the depressed part of the field had severe symptoms similar to those caused by the common scab bacterium. In tubers, nematodes were detected inside cross-lesions typical symptoms of common scab, and occurred also in the outermost 0.5 mm tissue associated with such lesions. In pots with sterile sand, micro-tubers of potato cv. Saturna, produced from meristems, were grown in a green-house infected with, P. penetrans, S. scabies, and a combination of P. penetrans and, S. scabies. P. penetrans alone induced tuber lesions similar to those of common scab. Also, the combined inoculation of the bacterium and the nematode seemed to enhance symptom expression. Similar scab symptoms, in connection with lesion nematode infections, have been observed on potato tubers cv. Oleva, which also is relatively tolerant to common scab. Symptomatic tubers cv. Saturna first stored at 4o C for 20 weeks were transferred to pots with sterile sand and grown for 3 months in the green-house. In these cultures P. penetrans was first detected in soil 8 weeks after planting. Examination at harvest of soil, roots, stolons, tubers demonstrated symptoms typical of P. penetrans. Interestingly, P. penetrans survives storage of potatoes, from which new infections may develop. Hence, potato tubers do appear to be an important means for the spread of P. penetrans to new areas. The fact that the symptoms induced by this nematode may be mistaken for symptoms of common scab suggests that the frequency of S. scabies might have been overestimated in regular surveys. Infections by P. penetrans have important implications for scab control. This pertains in particular to recommended maintenance of high soil moisture at and during 4-9 weeks after tuber set. If symptoms are related to nematode infection rather than to the scab bacterium, this recommendation would allow for a rapid build-up of lesion nematodes resulting in a decrease in both yield and marketability of the tubers. Further studies are needed to investigate the extent of this problem.

Sammendrag

Some species of plant parasitic nematodes restrict severely the productivity of crops. In Nordic countries nematodes are often overlooked as factors explaining crop failure. This neglect may relate to a 2/3 reduction of personnel in Nordic nematology which has happened since 1994. The resulting decrease in the lecturing and training of students threatens recruitment, scientific development and awareness of plant nematodes as parasites. This is serious since damage from nematodes can only be reduced by correct management of populations. This will contribute to soil health and a sustainable production. Potato cyst nematode (PCN), Globodera spp., is economically the most important pest attacking potato. It is difficult to detect in the fields, and 20 years may elapse before damage is noticed. The cost for managing PCN is high since management relies on intensive monitoring and regulation. PCN is mainly managed by crop rotations with non-hosts crops grown between alternating susceptible and resistant potato. Among cereal cyst nematodes (CCN) the most common species are Heterodera.avenae and H. filipjevi. Both species have pathotypes differing in their host preferences. Under Nordic conditions serious damage seems to appear with about 40-years intervals. For CCN, correct knowledge of species, pathotype and population density is essential in designing crop rotations. Optimal rotations may allow for yield increases of up to 1 t/ha. In Norway and Sweden damage from root knot nematodes (RKN), Meloidogyne hapla on vegetables and M. naasi on cereals, has been detected more frequently in recent years. RKN have their largest importance in continental and southern Europe, and the increase in field damage seen in the Nordic area may be a first sign of climate change. It is likely that also damage from other nematodes will increase with rising temperatures. Research cooperation between Nordic countries seems urgent to meet the future challenges in plant nematology.

Sammendrag

Studier av Potetcystenematoder (PCN) i nordlige områder Prosjektet skal forbedre bekjempelsen av potetcystenematoder (PCN). Dette skal oppnås ved å skaffe mer kunnskap om de ulike patotypene, populasjonsutvikling, nedgang av smitte når det ikke dyrkes poteter på arealet, eventuelle parasitter og utbredelsen av resistens i ulike potetsorter. Potetcystenematoder (PCN) har stor økonomisk betydning. Både den gule arten (yPCN), G. rostochiensis, og den hvite arten (wPCN), G. pallida, er karanteneskadegjørere og reguleres i Matloven. I Norge legges arealer infisert med wPCN eller virulente raser av yPCN i karantene på 40 år bl.a. med forbud mot dyrking av potet, produksjon av planter til videre dyrking og bortføring av jord. Prosjektets hovedmål er å forbedre den fremtidlige bekjempelsen av PCN ved å: (a) klarlegge patotypespekter i utvalgte populasjoner, (b) klarlegge smittenedgang og infeksjonspotensial i fravær av vertsplanter, (c) Initiere studier av forekomst og patogenitet til parasittære mikroorganismer på PCN, (d) studere populasjonsnedgang i felt med tidlig potet og Solanum sisymbriifolium og (e) undersøke resistens- og toleranse for PCN i potetsorter, (f) Initiere studier av pathosystemet (PCN-potet). Målet er å forbedre bekjempelsen av PCN og vurdere å åpne for kortere karanteneperiode. Ny kunnskap vil øke effektiviteten i norsk potetproduksjon. Identiteten til valgte populasjoner av PCN dokumenteres med mikroskopi, iso-elektrisk fokusering og DNAbaserte teknikker som PCR og RFLP. Patotypetest gjennomføres ved JKI Tyskland og ved Bioforsk Plantehelse (a). Smittenedgang i bestemt felt studeres på arealer som er karantenelagt siden 1955. Egg i PCN-cyster gjennomgår her klekketest og klekte juvenilers infeksjonsdyktighet og nematodenes reproduksjon undersøkes på mottakelig potet (b). Preliminære studier av forekomst og patogenitet hos parasittære mikroorganismer på PCN, samt identifikasjon og kvantifisering av mikroorganismer basert på molekylære metoder som qrt-PCR, DGGE i samarbeid med JKI Tyskland (c). I feltforsøk i Nord Trøndelag, Rogaland, østfold og Vestfold, undersøkes betydningen av tidligpotet og Solanum  sisymbriifolium for saneringen av PCN (d). Kartlegging av resistens –og toleranse hos norske noen markedssorter av potet undersøkes med PCN populasjoner av kjent art og patotype (e). Initialstudier av pathosystem- nematode/plante-interaksjon (proteomics) ved hjelp av molekylære metoder, gjennomføres ved Universidad Autonoma de Madrid Spania i samarbeid med Bioforsk Plantehelse (f).

Sammendrag

  mest avanserte og fremgangsrike planteparasitter. PCN ble påvist i Europa av Kühn i 1881, og i 1923 erklærer Wollenweber den som egen art. Stone i 1973 skiller PCN i to arter. Gul PCN (Globodera rostochiensis) og hvit PCN (G. pallida). I Norge ble PCN først påvist 1955 i Agderfylkene. PCN har spredt seg raskt og i1993 ble de første funn gjort i Nord-Trøndelag. På verdensbasis er PCN funnet utbredt i 23 land og har en begrenset forekomst i 42 land, og i tillegg er det 130 land det ikke er blitt påvist enda. Både gul og hvit PCN er klassifisert som karanteneskadegjørere i 106 respektive 55 land. I de siste årene har PCN blitt påvist i Australia, Canada og USA, som på nytt satt fokus på hvor lett PCN kan spres og hvilke nasjonale konsekvenser PCN har.   De plantesanitære og økonomiske konsekvensene av PCN er betydende. I EU vil PCN bli regulert i det nye EU direktivet 2007/33/EC som implementeres nå. Formålet med direktivet er å bergrense og kontrollere spredningen til PCN. I direktivet gjøres det ingen forskjell mellom gul og hvit PCN, det nevnes at arealer for settepotet og planter til videre dyrking må ha en offisiell dokumentasjon om PCN status, det skal årlig gjennomføres offisiell prøvetaking av 0,5 % av arealet av felt for produksjon av annen potet enn settepotet. Smittede felt får ikke brukes til produksjon av settepotet eller planter til videre dyrking. Bekjempelsestiltak iverksettes på smittede felt som skal brukes til produksjon av annen potet enn settepotet. Ved resistensbryting skal PCN populasjonen rasetestes. Det skal sendes en årsrapport til EU om tiltak som iverksettes i hvert land. I dag benyttes nematicider for å kontrollere PCN, og samtidig disponeres mye resurser for å foredle sorter med resistens.

Sammendrag

A major challenge facing agricultural scientists today is the need to secure food for an increasing world population. The World Bank in 2008 estimated a population increase of 35% by 2050. Reducing yield losses caused by pathogens of agricultural crops is one measure that can contribute to increased food production. Plant-parasitic nematodes are often important constraints on crop production; they can cause extensive damage and substantial yield losses. Nematode attack can also predispose plants to attack by other pathogens either through mechanical damage or on a genetic basis. These interactions between nematodes and other pathogens in disease complexes increase yield losses. The degree of damage can also be dependent on host plant and age. In addition, environmental and climatic conditions influence the nematode density. Damage that results from nematode attack affect not only the feeding cell, but reduces also the capacity of the root system, to take up nutrients and water. The decreasing availability of agrochemicals makes the situation complicated as the use of nematicides has been the principal tool for nematode management over the past decades. Nematode management strategies are targeted at preventing nematode multiplication and hence protect the crop from damage. In absence of nematicides the growing of resistant varieties is the most cost-effective and successful means of management. Combined with knowledge of the biology life-cycle, and the effects of cultural practices like crop rotation, organic amendment, growing resistant cultivars may minimize the effect of plant parasitic nematodes. To meet these challenges interdisciplinary research is needed.

Sammendrag

Potetcystenematodene (PCN) Globodera spp. er opprinnelig fra fjelltrakter i Peru og Bolivia. PCN er en av de mest avanserte og fremgangsrike planteparasitter. PCN ble påvist i Europa av Kühn i 1881, og i 1923 erklærer Wollenweber den som egen art. Stone i 1973 skiller PCN i to arter. Gul PCN (Globodera rostochiensis) og hvit PCN (G. pallida). I Norge ble PCN først påvist 1955 i Agderfylkene. PCN har spredt seg raskt og i1993 ble de første funn gjort i Nord-Trøndelag. På verdensbasis er PCN funnet utbredt i 23 land og har en begrenset forekomst i 42 land, og i tillegg er det 130 land det ikke er blitt påvist enda. Både gul og hvit PCN er klassifisert som karanteneskadegjørere i 106 respektive 55 land. I de siste årene har PCN blitt påvist i Australia, Canada og USA, som på nytt satt fokus på hvor lett PCN kan spres og hvilke nasjonale konsekvenser PCN har. De plantesanitære og økonomiske konsekvensene av PCN er betydende. I EU vil PCN bli regulert i det nye EU direktivet 2007/33/EC som implementeres nå. Formålet med direktivet er å begrense og kontrollere spredningen til PCN. I direktivet gjøres det ingen forskjell mellom gul og hvit PCN, det nevnes at arealer for settepotet og planter til videre dyrking må ha en offisiell dokumentasjon om PCN status, det skal årlig gjennomføres offisiell prøvetaking av 0,5 % av arealet av felt for produksjon av annen potet enn settepotet. Smittede felt får ikke brukes til produksjon av settepotet eller planter til videre dyrking. Bekjempelsestiltak iverksettes på smittede felt som skal brukes til produksjon av annen potet enn settepotet. Ved resistensbryting skal PCN populasjonen rase testes. Det skal sendes en årsrapport til EU om tiltak som iverksettes i hvert land. I dag benyttes nematicider for å kontrollere PCN, og samtidig disponeres mye resurser for å foredle sorter med resistens. Potetprodusenter i England bruker ca. Nok. 584 mill. pr år for å sikre sin potetproduksjon. Etter siste oppdagelse av PCN i Australia har mye ressurser blitt benyttet for å utrydde PCN, da det er blitt estimert at det vi koste ca. Nok 216 milliarder i en periode av 20 år hvis PCN blir utbredt i landet. I tillegg til Australia har land som Israel, USA og Canada investert store ressurser for å utrydde PCN, da de mener at på lang sikt er dette billigere enn å leve med PCN. For å gjøre dette mulig har disse land satt i verk strenge restriksjoner. Disse restriksjonene omfatter forbud mot å dyrke potet og andre vertsplanter, benytte store menger nematicider, og prøvetaking. I USA har det 2006-2009 blitt analysert 257 700 prøver, etter påvising av hvit PCN i 9 felt i Idaho. USA har som målsetting å utrydde PCN på 7 år. Som resultat av EU:s direktiv (EC) No 1107/2009 om begrensning av giftige kjemikaler som forårsaker som forårsaker helse- og miljøproblem forventes bruket av de fleste nematicidene å være forbudt i 2015. For å imøtekomme disse utfordringene har forskere i Storbritannia startet sekvensering av hvit PCN. Det er ledet av University of Leeds, i samarbeid med Rothamsted Research, SCRI, og Sangers Institute, og har et budsjett av Nok 15 mill. Det forventes at dette kan gi nye bærekraftige alternativer til bekjempelse av PCN. I tillegg bruker andre Europeiske land ressurser på å finne alternativer for bekjempelse med fangevekster og biofumiganter. I det fleste land omfatter bekjempelse i dag bruk av nematicider, bruk av sertifisert settepotet, og kontrollert bruk av resistente sorter for å unngå oppformering av resistensnedbrytende raser. I tillegg har de et karanteneregelverk. Dette bidrar til en lønnsom potetproduksjon.

Sammendrag

The correct identification to species and pathotype is of crucial importance for the kind management and regulations to be imposed in Norway as G. pallida and G. rostochiensis species are quarantine pests regulated in the national plant health legislation. Identification is in accordance with the EPPO diagnostic protocol.  Morphology, Iso electric focousing and molecular methods are used. Today, non-virulent G. rostochiensis is managed by crop rotation, while infestations by G. pallida or virulent G. rostochiensis results in at least 40-years ban for growing potato.

Sammendrag

In 1955 the potato cyst nematode (PCN) was recorded for the first time in Norway. This detection resulted in extensive surveys and measures were implemented based on the statutory regulation of 1916. The first statutory regulation for PCN was put in power in 1956, and later amended in several occasions. These regulations prohibit the introduction and spread of PCN with soil and plant materials. Early control strategies included the use of chemical fumigants and resistant potato cultivars in infested fields, and surveys detected new infestations which were placed under quarantine regulations. The recognition of G. rostochiensis and G. pallida, their pathotypes enabled a more precise use of resistant cultivars. Commercial chemical fumigants, organophosphates or carbamate nematicides have not been used in Norway since the early 1970s. Today, non-virulent G. rostochiensis is managed by crop rotation, while infestations by G. pallida or virulent G. rostochiensis results in at least 40-years ban for growing potato. Most Norwegian potato cultivars have the resistance genes, Gro-1 (H1) from Solanum tuberosum ssp. andigena.  During the preceding decades great emphasis has been placed on documenting freedom from PCN in the production of certified seed potatoes, certified seed potato are used in combination with crop rotations using non-host crops, alternating susceptible and resistant cultivars. These are important control measures, but not easy to implement in Norway due to restricted acreage suitable for long rotations. The safe use of resistant potato cultivars requires a better knowledge on the presence of species and pathotypes in potato fields. In order to improve our information of the occurrence of PCN a new national survey program for the principal potato districts has started. These surveys will complemented by information generated from a new research project dealing with: studies of the virulence of selected PCN populations, decline rates of nematode field population densities and infection potential over time of populations from fields placed under quarantine regulations. studies on the occurrence and pathogenicity of microbial antagonistic parasitic on PCN, and their potential of future management of PCN, the safe use of early potato cultivars as a practical control method, and the potential for using Solanum sisymbriifolium as a trap crop, distinguish the degree of resistance of selected potato varieties available on the Norwegian market, and initial studies of the PCN-Potato-Pathosystem. These expected results of this project possibly will improve the management of PCN, and may alleviate present regulatory restrictions.

Sammendrag

In 1955 the potato cyst nematode (PCN) was recorded for the first time in Norway. This detection resulted in extensive surveys and measures were implemented based on the statutory regulation of 1916. The first statutory regulation for PCN was put in power in 1956, and later amended in several occasions. These regulations prohibit the introduction and spread of PCN with soil and plant materials. Early control strategies included the use of chemical fumigants and resistant potato cultivars in infested fields, and surveys detected new infestations which were placed under quarantine regulations. The recognition of G. rostochiensis and G. pallida, their pathotypes enabled a more precise use of resistant cultivars. Commercial chemical fumigants, organophosphates or carbamate nematicides have not been used in Norway since the early 1970s. Today, non-virulent G. rostochiensis is managed by crop rotation, while infestations by G. pallida or virulent G. rostochiensis results in at least 40-years ban for growing potato. Most Norwegian potato cultivars have the resistance genes, Gro-1 (H1) from Solanum tuberosum ssp. andigena. During the preceding decades great emphasis has been placed on documenting freedom from PCN in the production of certified seed potatoes, certified seed potato are used in combination with crop rotations using non-host crops, alternating susceptible and resistant cultivars. These are important control measures, but not easy to implement in Norway due to restricted acreage suitable for long rotations. The safe use of resistant potato cultivars requires a better knowledge on the presence of species and pathotypes in potato fields. In order to improve our information of the occurrence of PCN a new national survey program for the principal potato districts has started. These surveys will complemented by information generated from a new research project dealing with: studies of the virulence of selected PCN populations, decline rates of nematode field population densities and infection potential over time of populations from fields placed under quarantine regulations. studies on the occurrence and pathogenicity of microbial antagonistic parasitic on PCN, and their potential of future management of PCN, the safe use of early potato cultivars as a practical control method, and the potential for using Solanum sisymbriifolium as a trap crop, distinguish the degree of resistance of selected potato varieties available on the Norwegian market, and initial studies of the PCN-Potato-Pathosystem. These expected results of this project possibly will improve the management of PCN, and may alleviate present regulatory restrictions.

Sammendrag

In Nordic countries organic farming started as bio-dynamic farms in the 1930s, and still in the 1970s only a small number of farms were organic. Since then the acreage of organic farming has increased and in 2007 Sweden had 222 268 ha (7.9%), Finland 147 557 ha (6.4 %), Denmark 147 482 ha (5.4%), Norway 43 033 ha (4.7%) and Iceland 4 684 ha (0.27%). In northern areas the short vegetation period combined with low temperatures reducing mineralisation causing nutritional deficit may restrict yields. As mineral fertilizers are prohibited in organic farming, plant nutrition and yield depend on proper microbial activity for nutrient cycling. Plant parasitic nematodes (PPN) reduce plant growth, while microbivorous nematodes (MBN) increase nutrient accessibility. Nitrogen fixating legumes, used to improve soil nitrogen levels, may increase densities of PPN to levels causing crop damage. Management of PPN in organic farming relies on knowledge of population dynamics, damaging thresholds and cultural methods like weed control, sanitation, mulching, crop rotation and resistant cultivars. Keeping PPN below damaging levels and supporting beneficial MBN to improve mineralisation would increase yields and improve quality of organics crops in northern areas. Management of MBN is less well understood, but may be of crucial importance for organic farming in northern areas.

Sammendrag

Soil samples from a growth depression in potato (Solanum tuberosum) cv. Saturna field in Grue, eastern Norway, yielded large numbers of root lesion nematodes, Pratylenchus penetrans. Yield of potato was reduced by 50% in the affected area of the field. Transect-sampling showed plant growth to be negatively correlated with densities of P. penetrans and suggested a damage threshold of potato to the nematode of 100 specimens per 250 g of soil. Common scab (Streptomyces scabies) occurred frequently in the affected area. Pratylenchus penetrans was present in roots, underground stems, stolons and tubers. In tubers, nematodes were detected inside cross-lesions typical of common scab, and occurred also in the outermost 0.5 mm tissue associated with such lesions. On potato cv. Saturna grown in a green-house, P. penetrans alone induced tuber lesions similar to those of common scab. Also, the combined inoculation of the bacterium and the nematode seemed to enhance symptom expression. Pratylenchus penetrans survives storage of potatoes, from which new infections may develop. Hence, potato tubers do appear to be an important means for the spread of P. penetrans to new areas.

Sammendrag

Norwegian cereal cyst nematode populations were studied by biochemical, molecular, morphological and bio test techniques. H. avenae occurred in the pathotypes, Ha11, Ha12, and H. avenae Våxtorp. H. filipjevi was recorded as pathotype West. H. avenae (Ha 11) and H. filipjevi West were the most common species. Thirty barley, 23 oat and 6 of summer wheat cultivars on the Norwegian market were tested for their resistance against H. avenae (Ha11), H. avenae Våxtorp and H. filipjevi West. Resistance against Ha11 was found in 5 barley, 3 oat and in 1 wheat cultivar. Resistance against H. avenae Våxtorp was not present in barley, but 4 oat and 1 wheat cultivar were resistant. For H. filipjevi West resistance was not detected in wheat, but in 6 barley and 13 oat cultivars. A management system based on careful nematode identification and knowledge on resistance of cultivars were set in operation in the county of Vestfold. As a result farmers have improved average yields by 1000 kg /ha. By implementing this program in full the county of Vestfold could make an annual gain of 800 000 €. In perspective of increasing damage from CCN world-wide the correct identification of species and the recognition of their genetic variability is instrumental for successful control.

Sammendrag

Norwegian cereal cyst nematode populations were studied by biochemical, molecular, morphological and bio test techniques. H. avenae occurred in the pathotypes, Ha11, Ha12, and H. avenae Våxtorp. H. filipjevi was recorded as pathotype West. H. avenae (Ha 11) and H. filipjevi West were the most common species. Thirty barley, 23 oat and 6 of summer wheat cultivars on the Norwegian market were tested for their resistance against H. avenae (Ha11), H. avenae Våxtorp and H. filipjevi West. Resistance against Ha11 was found in 5 barley, 3 oat and in 1 wheat cultivar. Resistance against H. avenae Våxtorp was not present in barley, but 4 oat and 1 wheat cultivar were resistant. For H. filipjevi West resistance was not detected in wheat, but in 6 barley and 13 oat cultivars. A management system based on careful nematode identification and knowledge on resistance of cultivars were set in operation in the county of Vestfold. As a result farmers have improved average yields by 1000 kg /ha. By implementing this program in full the county of Vestfold could make an annual gain of 800 000 €. In perspective of increasing damage from CCN world-wide the correct identification of species and the recognition of their genetic variability is instrumental for successful control.

Sammendrag

Cereal cyst nematodes (CCN), Heterodera spp. are well-known world-wide as parasites of cereals. In Scandinavia H. avenae is the most common species and occurs in the pathotypes, Ha11 and Ha12, and the additional pathotypes H. avenae-Knislinge, H. avenae-Ringsåsen and H. avenae-Våxtorp. H. filipjevi, which occurs in the two pathotypes, "East" and "West" is less common than H. avenae.  For several years it has been known that resistance to cereal cyst nematodes may be found in some commercial cultivars, although no conscious breeding for resistance has been attempted. In 2004 and 2005 a majority of cereal cultivars on the Norwegian market were tested for susceptibility/resistance towards H. avenae pathotype Ha11, H. avenae pathotype "Våxtorp" and H. filipjevi pathotype "West" The test program included 30 cultivars of barley, 23 cultivars of oats and 6 cultivars of summer wheat. Resistance against Ha11 was found in 5 barley, 3 oat cultivars and in 1 wheat cultivar. Resistance against H. avenae pathotype "Våxtorp" was not present in barley, but 4 oat cultivars and 1 wheat cultivar were resistant. For H. filipjevi "West" resistance was not detected in wheat, but in 6 barley and 13 oat cultivars. Obviously the variability in CCN is larger than generally anticipated. In Norway management systems based on careful nematode identification and good knowledge of suitable resistant cultivars are in operation. Resistant barley is generally recommended when nematode populations are high due to its high tolerance compared to resistant oats. Farmers implementing this program have reported increased cereal yields of in average 1000 kg /ha. It has been calculated that by implementing this program in full the county of Vestfold could make an economic gain of 800 000 € annually. In perspective of increasing damage from CCN world-wide the recognition of its genetic variability is instrumental for successful control.

Sammendrag

To arter av rotgallnematoder, Meloidogyne hapla og M. ardenensis, er vanlige å finne på friland i Norge. Sommeren 2008 ble det funnet en tredje art, M. naasi, på skadet hvete i Vestfold. Funnene er de første av denne rotgallnematoden i Norge og Skandinavia. Den er også funnet på flere ugras. M. naasi er en viktig skadegjører på bygg i tempererte områder.

Sammendrag

To arter av rotgallnematoder, Meloidogyne hapla og M. ardenensis, er vanlige å finne på friland i Norge. Sommeren 2008 ble det funnet en tredje art, M. naasi, på skadet hvete i Vestfold. Funnene er de første av denne rotgallnematoden i Norge og Skandinavia. Den er også funnet på flere ugras. M. naasi er en viktig skadegjører på bygg i tempererte områder.

Sammendrag

The Altiplano is one of the most elevated areas populated in the world. At 3 500 - 4 000 m, low temperature, and other climatic conditions impose severe limitation for vegetable production. The average temperature levels and the daily amplitudes is a function of altitude, so vegetables are mainly produced in rustic greenhouses. NGOs in the Andean region have recommended cultivation of vegetables for consume and commercialization to enhance the well being of farmers. Plant parasitic nematodes or poor management have limited the vegetable production in rustic greenhouse. The Catholic University of Bolivia has a network of rural campuses "Unidades Académicas Campesinas" (UAC) for academic and practical teaching. Bioforsk has been involved in developing and strengthening the scientific basis in Plant Nematology in UAC-Tihauanaco. Farmers in Tiahuanaco experienced decreasing vegetable yields. In 1999 soil and plant samples from potato and other Andean crops were collected from greenhouses. All samples contained plant-parasitic nematodes. Twenty-one genera of plant-parasitic nematodes were found. The most frequent were potato cyst nematodes Globodera rostochiensis and the false root-knot nematode Nacobbus sp. (54 %), followed by lesion nematodes Pratylenchus spp. spiral Helicotylenchus sp. and Tylenchus sensu lato (41 %), ring nematodes Criconemella sp. (34 %), stunt nematodes Tylenchorhynchus spp. (29 %) and root-knot nematodes Meloidogyne sp. (19 %). The study indicated that plant-parasitic nematodes have a large impact on vegetable production. The knowledge of nematode species are of fundamental importance in the design of efficient management strategies, that would allow farmers to keep nematode population densities at levels below the threshold of economic damage. Management with crop rotation and the use of cultivars with resistance are important control measures, but require detailed information on the occurrence and density of nematode species.

Sammendrag

Plantevernleksikonet. Oppslagsord: Nematoder Rotsårnematoder Meloidogyne spp. Meloidogyne arenaria Meloidogyne javanica Meloidogyne incognica Meloidogyne hapla Meloidogyne ardenensis Potetcystenematoder Gul potetcystenematode Hvit potetcysttenematode Korncystenematoder For hver skadegjører gis det en oversikt over utseende, utbredelse, vertplanter, livssyklus, skadevirkninger og bekjempelse.

Sammendrag

A survey was undertaken to investigate the occurrence of plant parasitic nematodes in the municipality of Lier located in southern Norway. A wide variety of vegetables crops are grown in this area. Soils in Lier are mostly sandy loam, and irrigation is practiced when necessary during the growing season. There is little information on the occurrence on plant parasitic nematodes in vegetables; particularly in areas where farmers have specialized in intensive production, and often grow two to three cultures of vegetables during the growing season. In the year prior to this investigation several crops had been observed with symptoms of attack by plant parasitic nematodes. The aim of this survey was to identify the species responsible for the damage. The emphasis was placed on genera of known economic importance. During the end of the growing season plants showing poor growth or symptoms of nematode damage and plants with healthy appearance were sampled. A total of 74 root samples were collected and assessed for galls and 37 soil samples were collected from the rhizospheres. In the study samples were collected from 7 producers. Five samples were taken from cauliflower (Brassica oleraceae var. botrytis), 4 from broccoli (Brassica oleraceae var. italica), 8 from pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis), 8 from lettuce (Lactuca sativa) and 1 from celery (Apium graveolens). Soil sampling included 11 samples from areas with fallow, ploughed and rotocultivated land. Root knot nematodes were not recorded in the root samples. In soil samples economically important nematode genera were recorded. Tylenchorhynchus sp. (72.9 % of samples), was the most frequently encountered genus, followed by the species Heterodera cruciferae and other Heterodera spp. (67.5 %), Pratylenchus spp. (54 %), Paratylenchus spp. (29,7 %), and Helicotylenchus spp. (8.1 %). In addition to cyst detections Heterodera juveniles were found in 32.4 % of samples. In all the samples from Pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis) Heterodera cruciferae was recorded, symptoms of nematode damage was also observed in the field. The results of the survey will help in planning future research as well as in developing effective nematode management strategies suitable for vegetable producer particularly in this area. The authors are thankful to the FMLA in Buskerud County for economical support.

Sammendrag

A survey was undertaken to investigate the occurrence of plant parasitic nematodes in the municipality of Lier located in southern Norway. A wide variety of vegetables crops are grown in this area. Soils in Lier are mostly sandy loam, and irrigation is practiced when necessary during the growing season. There is little information on the occurrence on plant parasitic nematodes in vegetables; particularly in areas where farmers have specialized in intensive production, and often grow two to three cultures of vegetables during the growing season. In the year prior to this investigation several crops had been observed with symptoms of attack by plant parasitic nematodes. The aim of this survey was to identify the species responsible for the damage. The emphasis was placed on genera of known economic importance. During the end of the growing season plants showing poor growth or symptoms of nematode damage and plants with healthy appearance were sampled. A total of 74 root samples were collected and assessed for galls and 37 soil samples were collected from the rhizospheres. In the study samples were collected from 7 producers. Five samples were taken from cauliflower (Brassica oleraceae var. botrytis), 4 from broccoli (Brassica oleraceae var. italica), 8 from pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis), 8 from lettuce (Lactuca sativa) and 1 from celery (Apium graveolens). Soil sampling included 11 samples from areas with fallow, ploughed and rotocultivated land. Root knot nematodes were not recorded in the root samples. In soil samples economically important nematode genera were recorded. Tylenchorhynchus sp. (72.9 % of samples), was the most frequently encountered genus, followed by the species Heterodera cruciferae and other Heterodera spp. (67.5 %), Pratylenchus spp. (54 %), Paratylenchus spp. (29,7 %), and Helicotylenchus spp. (8.1 %). In addition to cyst detections Heterodera juveniles were found in 32.4 % of samples. In all the samples from Pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis) Heterodera cruciferae was recorded, symptoms of nematode damage was also observed in the field. The results of the survey will help in planning future research as well as in developing effective nematode management strategies suitable for vegetable producer particularly in this area. The authors are thankful to the FMLA in Buskerud County for economical support.

Sammendrag

Planteparasittære nematoder er små rundormer som skader røttene på korn. Symptomene viser seg som tynn plantebestand, svake planter og mer ugras. I de siste årene viser henvendelser fra produsenter at problemene med nematoder er økende. Prøver med korncystenematoder, rotsårnematoder og stuntnematoder er vanlig. I prøvene hvor resistente sorter for korncystenematoder er dyrket, og skader vises, er ofte rotsårnematoder funnet. Rotsårnematoder er påvist i forbindelse med skader i alle kornarter. I en del av feltene som er undersøkt i Vestfold, Østfold, Agder, Romerike og Buskerud er det vist til dels høge populasjoner av rotsårnematoder.

Sammendrag

Planteparasittære nematoder er små rundormer som skader røttene på korn. Symptomene viser seg som tynn plantebestand, svake planter og mer ugras. I de siste årene viser henvendelser fra produsenter at problemene med nematoder er økende. Prøver med korncystenematoder, rotsårnematoder og stuntnematoder er vanlig. I prøvene hvor resistente sorter for korncystenematoder er dyrket, og skader vises, er ofte rotsårnematoder funnet. Rotsårnematoder er påvist i forbindelse med skader i alle kornarter. I en del av feltene som er undersøkt i Vestfold, Østfold, Agder, Romerike og Buskerud er det vist til dels høge populasjoner av rotsårnematoder.

Sammendrag

Bioforsk gjennomførte i samarbeid med Lier og omegn forsøksring en kartlegging av planteparasittære nematoder i Lier. Dette p.g.a. at det i 2006 ble påvist skader av nematoder i stilkselleri hos en dyrker i Lier. I vekstsesongen 2007 ble det gjort undersøkelser i 37 prøver fra grønnsakfelt fra 7 produsenter, hvor det ble dyrket blomkål, brokkoli, kinakål, isberg salat, stangselleri, og fra felter som var brakk/pløyd/frest. Det ble funnet stuntnematoder (Tylenchorhynchus sp.)i 27 prøver (72,9 %), Kålcystenematoder (Heterodera cruciferae) og cystenematoder (Heterodera spp.) i 25 prøver (67,5 %), rotsårnematoder (Pratylenchus spp.) i 20 prøver (54 %), pin-nematoder (Paratylenchus spp.)i 11 prøver (29,7 %), og spiralnematoder i 3 prøver (8,1 %).

Sammendrag

Bioforsk gjennomførte i samarbeid med Lier og omegn forsøksring en kartlegging av planteparasittære nematoder i Lier. Dette p.g.a. at det i 2006 ble påvist skader av nematoder i stilkselleri hos en dyrker i Lier. I vekstsesongen 2007 ble det gjort undersøkelser i 37 prøver fra grønnsakfelt fra 7 produsenter, hvor det ble dyrket blomkål, brokkoli, kinakål, isberg salat, stangselleri, og fra felter som var brakk/pløyd/frest. Det ble funnet stuntnematoder (Tylenchorhynchus sp.) i 27 prøver (72,9 %), Kålcystenematoder (Heterodera cruciferae) og cystenematoder (Heterodera spp.) i 25 prøver (67,5 %), rotsårnematoder (Pratylenchus spp.) i 20 prøver (54 %), pin-nematoder (Paratylenchus spp.) i 11 prøver (29,7 %), og spiralnematoder i 3 prøver (8,1 %).

Sammendrag

Potetcystenematodene (PCN), Globodera spp., har stor økonomisk betydning nasjonalt og internasjonalt. Både gul PCN (G. rostochiensis) og hvit PCN (G. pallida) er karanteneskadegjørere som reguleres gjennom Matloven. Infeksjon med PCN fører til økte produksjons -kostnader, tap i eiendommens salgsverdi og økonomiske problem for potetindustrien. De samfunnsmessige konsekvensene er derfor mye større enn avlingstapet. Prosjektet ble gjennomført på jord smittet med hvit potetcystenematode (wPCN) hos Jorstein Ertsgård på Bakken gård i Stjørdal, Nord-Trøndelag. Det ble gjennomført like forsøk med 24 forsøksledd i hvert av tre år (2005-2007). Det ble tatt prøver av smittet jord hver vår og høst, respektivt i initialpopulasjon (Pi) og sluttpopulasjonen (Pf). Alle planlagte analyser med hensyn på smitteutvikling er gjennomførte og resultatene presenteres her. Sammenligning av PCN-formeringen innen hver behandling gjøres med kvoten Pf/Pi, oppformeringsfaktoren. Rekkefølgen mellom behandlingene i Pf/Pi-verdi, skiftet fra år til år, men i gjennomsnitt for alle behandlinger var det en kraftig nedgang fra 2005 til 2006, mens det igjen var en økning i 2007. Økningen i 2007 skyldtes for en stor del en unormalt kraftig oppblomstring av nematodesmitte i fangpotet på høsten. Dersom man ser på endring av sluttpopulasjonen (Pf) i prosent for hver behandling i forhold til kontroll (mottakelig potetsort "Laila"), så var det en kraftig nedgang i smitteprosent fra 2005 til 2006 og en ytterligere nedgang til 2007. Mengde smitte i kontrollbehandlingen holdt seg høy i hele forsøksperioden og nivået var høyest høsten 2007. Jord med fangpotet hadde klart mindre nematoder enn potet, bladfaks, timotei og raigras i 2006, men kom bare bedre ut enn kontroll i 2007. Tilsetting av avfallsproduktene syltetøy, potetrasp, beinmel og et biologisk middel ga ikke bedre resultater enn brakklegging, og regnes derfor som uaktuelle som eneste behandling mot wPCN. Når man sammenligner nematodepopulasjonens endring i middel av alle år så var det forskjell mellom dyrkingsaktuelle vekster. Hvitløk, bringebær og hodekål hadde lavere smitteprosent i forhold til potet, enn bygg, kepaløk, engkvein, høsthvete, jordbær, bladfaks, raigras og rose, og de tre siste vekstene kom spesielt dårlig ut med hensyn til smittenedgangen. Dersom man ser på smittenedgangen innen hver vekst var hvitløk og bringebær bedre enn engkvein, raigras, rødsvingel og rose. Jordbær var bedre enn raigras, rose og engkvein, mens hodekål var bedre enn raigras og rose. På grunnlag av dette vil de mest aktuelle vekstene for dyrking være hvitløk, bringebær, hodekål, bygg, kepaløk og rødsvingel. Raigras og rose bør unngås om man ønsker en rask reduksjon av smitten. Avfallsprodukter som beinmel, potetrasp og syltetøy kan brukes som tilsetning til jorden i forbindelse med dyrking av aktuelle vekster uten å forverre smittesituasjonen. Prosjektet har gitt et første innblikk i smitteendring som resultat av dyrkingstiltak, og vil på sikt være en viktig dokumentasjon som kan utløse målrettede nye prosjekter på området.

Sammendrag

I verdensmålestokk er potetcystenematoder (PCN) (Globodera spp.) Kjent som alvorlige skadegjørere på potet. Nematodenes sterke spesialisering til potet som vertsplante har ført til en overlevelsesevne i jord som er stor utfordring for potetdyrkingen. Virulente populasjoner som kan oppformeres på resistent potet er en annen grunn for bekymring. Både den gule arten (yPCN) G. rostochiensis og den hvite arten (wPCN) G.pallida er klassifisert som karanteneskadegjørere og er regulert i Matloven. Bekjempelse av ikke virulent (yPCN) bygger på vekstskifte med resistent potet, ikke-vertsplanter og mottakelig potet. Bekjempelse av wPCN gjøres i dag ved at infiserte bruksenheter legges i karantene i 40 år med dyrkingsforbud for vertsplanter og annen aktivitet som risikere å sprede nematoden.

Sammendrag

El Altiplano es una de las areas mas pobladas en el mundo. Localizada a una altitud de 3500 " 4000 m, las bajas temperaturas restringe la producción de hortalizas a campo abierto. Por lo cual la major parte de hortalizas son producidas en invernaderos rústicos (carpas solares), fabricados con material local y con techos de plasticos transparente. NGOs en la region Andina han recomendado el cultivo de hortalizas para consumo y comercialización, con el proposito de incrementar y balancear la dieta alimenticia e incrementar los ingresos de los agricultores. Nemátodos fitoparásitos o el escaso manejo de estos limitan frecuentemente la producción en los invernaderos. La universidad Catolica Boliviana, tiene sus Unidades Académicas Campesinas (UAC) en el area rural dedicadas a la enseñanza practica a personas con escasos recursos, quienes, después de su formación profesional puedan contribuir al desarrollo de sus comunidades de origen. Bioforsk ha participado en el desarrollo y fortalecimiento de las bases cientificas en Nematologia de Plantas en UAC-Tiahuanaco. Agricultores en Tiahuanaco experimentaban bajos rendimientos en la producción de hortalizas. Un muestreo de nemátodos parásitos de plantas se realizo para dar apoyo a los agricultores de esta area. Muestras de suelo y plantas se recolectaron en 1999. En Todas las muestras se encontraron nemátodos parásitos de plantas. Veinticuatro muestras conteniendo suelo y plantas provienen de papa (Solanum spp.) y otros cultivos andinos. Diecisiete muestras fueron de invernaderos rústicos. Veintiun generos de nemátodos parásitos de plantas se encontraron. Los mas frecuentes fueron nemátodo del quiste de la papa Globodera rostochiensis y el nemátodo del rosario Naccobus sp. (54 %), seguidos por el nemátodo de las lesiones Pratylenchus spp., nemátodo espiral Helicotylenchus sp. Tylenchus sensu lato(41 %), nemátodo del anillo Criconemella sp. (34 %), stunt nemátodos Tylenchorhynchus spp. (29 %) y por ultimo el nemátodo agallador Meloidogyne sp. (19 %). El studio indica que nemátodos fitoparásitos tienen un efecto drastico en el rendimiento y la producción de hortalizas.

Sammendrag

El Altiplano es una de las areas mas pobladas en el mundo. Localizada a una altitud de 3500 " 4000 m, las bajas temperaturas restringe la producción de hortalizas a campo abierto. Por lo cual la major parte de hortalizas son producidas en invernaderos rústicos (carpas solares), fabricados con material local y con techos de plasticos transparente. NGOs en la region Andina han recomendado el cultivo de hortalizas para consumo y comercialización, con el proposito de incrementar y balancear la dieta alimenticia e incrementar los ingresos de los agricultores. Nemátodos fitoparásitos o el escaso manejo de estos limitan frecuentemente la producción en los invernaderos. La universidad Catolica Boliviana, tiene sus Unidades Académicas Campesinas (UAC) en el area rural dedicadas a la enseñanza practica a personas con escasos recursos, quienes, después de su formación profesional puedan contribuir al desarrollo de sus comunidades de origen. Bioforsk ha participado en el desarrollo y fortalecimiento de las bases cientificas en Nematologia de Plantas en UAC-Tiahuanaco. Agricultores en Tiahuanaco experimentaban bajos rendimientos en la producción de hortalizas. Un muestreo de nemátodos parásitos de plantas se realizo para dar apoyo a los agricultores de esta area. Muestras de suelo y plantas se recolectaron en 1999. En Todas las muestras se encontraron nemátodos parásitos de plantas. Veinticuatro muestras conteniendo suelo y plantas provienen de papa (Solanum spp.) y otros cultivos andinos. Diecisiete muestras fueron de invernaderos rústicos. Veintiun generos de nemátodos parásitos de plantas se encontraron. Los mas frecuentes fueron nemátodo del quiste de la papa Globodera rostochiensis y el nemátodo del rosario Naccobus sp. (54 %), seguidos por el nemátodo de las lesiones Pratylenchus spp., nemátodo espiral Helicotylenchus sp. Tylenchus sensu lato(41 %), nemátodo del anillo Criconemella sp. (34 %), stunt nemátodos Tylenchorhynchus spp. (29 %) y por ultimo el nemátodo agallador Meloidogyne sp. (19 %). El studio indica que nemátodos fitoparásitos tienen un efecto drastico en el rendimiento y la producción de hortalizas.

Sammendrag

Cereal cyst nematodes, Heterodera spp., are known world wide as parasites of cereals and grasses. Surveys in Norway have revealed that nematodes belonging to the H. avenae complex occur throughout the country. The cereal cyst nematode species so far recorded in Norway are H. avenae, H. filipjevi, H. pratensis, H. bifenestra and H. hordecalis. Within H. avenae the pathotypes, Ha 11 and Ha 12, "Ha- Knislinge", "Ha- Ringsåsen" and "Ha- Våxtorp" have been encountered. H. filipjevi is represented by the pathotype "West" HfW (Holgado et al., 2007). In cereals, peaks in cyst nematode populations and damage occur every 20-30 years, and seem to occur simultaneously throughout the Scandinavian Peninsula. We do not have reliable information on the mechanisms behind these wide spread fluctuations. Crop rotation and the use of cultivars with resistance are important measures for controlling cereal cyst nematodes, but require detailed information on the occurrence and density of species and pathotypes in the fields (Holgado & Andersson 2005, Holgado et al. 2005, 2006ab). In field soils Ha 11,/12, "Ha-Våxtorp" is often found together with HfW. Resistant cultivars are normally resistant to only one of two species or pathotypes in mixed field populations. Consequently the use of resistant cultivars will lead to an increase of the nematode species or pathotype capable of reproduction, which results in peaks of damage distributed in time. Failure in recognizing the time span of this dynamic may leave the farmer without access to appropriate cultivars when damage occurs. Different species and pathotypes of cyst nematodes may occur simultaneously on the same plant root (Holgado & Magnusson, 2007). This would be an unlikely event without mechanisms reducing competition. Differences in temporal, spatial and physiological niche dimensions between species would support diversity. A better knowledge of key-differences in niche parameters of cereal cyst nematode species would allow for an active management of specific populations, and stabilize their population densities at levels below the threshold of economic damage. Management of niches is management of diversity, and this would allow for an optimal selection of cultivars. In this way the unexpected peaks in cereal damage can be avoided to the benefit of a more stable and sustainable production. The dynamics and principles of coexistence of species in mixed populations need a stronger emphasis in management systems for cereal cyst nematodes.

Sammendrag

Cereal cyst nematodes, Heterodera spp., are known world wide as parasites of cereals and grasses. Surveys in Norway have revealed that nematodes belonging to the H. avenae complex occur throughout the country. The cereal cyst nematode species so far recorded in Norway are H. avenae, H. filipjevi, H. pratensis, H. bifenestra and H. hordecalis. Within H. avenae the pathotypes, Ha 11 and Ha 12, "Ha- Knislinge", "Ha- Ringsåsen" and "Ha- Våxtorp" have been encountered. H. filipjevi is represented by the pathotype "West" HfW (Holgado et al., 2007). In cereals, peaks in cyst nematode populations and damage occur every 20-30 years, and seem to occur simultaneously throughout the Scandinavian Peninsula. We do not have reliable information on the mechanisms behind these wide spread fluctuations. Crop rotation and the use of cultivars with resistance are important measures for controlling cereal cyst nematodes, but require detailed information on the occurrence and density of species and pathotypes in the fields (Holgado & Andersson 2005, Holgado et al. 2005, 2006ab). In field soils Ha 11,/12, "Ha-Våxtorp" is often found together with HfW. Resistant cultivars are normally resistant to only one of two species or pathotypes in mixed field populations. Consequently the use of resistant cultivars will lead to an increase of the nematode species or pathotype capable of reproduction, which results in peaks of damage distributed in time. Failure in recognizing the time span of this dynamic may leave the farmer without access to appropriate cultivars when damage occurs. Different species and pathotypes of cyst nematodes may occur simultaneously on the same plant root (Holgado & Magnusson, 2007). This would be an unlikely event without mechanisms reducing competition. Differences in temporal, spatial and physiological niche dimensions between species would support diversity. A better knowledge of key-differences in niche parameters of cereal cyst nematode species would allow for an active management of specific populations, and stabilize their population densities at levels below the threshold of economic damage. Management of niches is management of diversity, and this would allow for an optimal selection of cultivars. In this way the unexpected peaks in cereal damage can be avoided to the benefit of a more stable and sustainable production. The dynamics and principles of coexistence of species in mixed populations need a stronger emphasis in management systems for cereal cyst nematodes.

Sammendrag

Planteparasittære nematoder (rundormer) lever i jord og planter. Nematodene er av mikroskopisk størrelse, og noen arter fremkaller alvorlige skader på kulturplantene ved å suge på røtter og andre plantedeler. Korn kan skades alvorlig av nematodeangrep.

Sammendrag

Planteparasittære nematoder (rundormer) lever i jord og planter. Nematodene er av mikroskopisk størrelse, og noen arter fremkaller alvorlige skader på kulturplantene ved å suge på røtter og andre plantedeler. Korn kan skades alvorlig av nematodeangrep. Nyere studier viser et stort mangfold av korncystenematoder (Holgado et al., 2004). Vanlige arter og raser i Norge er H. avenae (Ha 11, Ha 12 og Ha Våxtorp) og rugcystenematoden H. filipjevi (rase Vest), mens artene H. pratensis, H. bifenestra og H. hordecalis er mindre hyppig forekommende (Holgado et al., 2007). Vi vet i dag alt for lite om de forandringer på artsnivå som ligger bak disse langsiktige populasjonsbølgene og skadene.

Sammendrag

Korncystenematoder (Heterodera spp.) er små rundormer som skader røttene på korn og andre grasarter. I korn viser symptomene seg som tynt plantebestand, svake planter og mer ugras. Skadebildet kan forveksles med surjordskade. Angrep av korncystenematoder forekommer nesten utelukkende på lette jordarter.

Sammendrag

Uforklarlige skader i hagen kan være forårsaket av planteparasittære nematoder. Planter med ujevnt vekst, deformerte blader eller buskete deformerte røtter er noen av nematodesymptomene. Nematoder er mikroskopiske rundormer som lever i jord, planter og dyr. De fleste er saprofytter, men noen fremkaller alvorlige skader på plantene ved at de suger på røtter og andre plantedeler. Dreneringen av næring samtidig med at enzymer sprøytes inn i plantene fører til misvekst avlingstap, og kvalitetsfeil. Noen nematoder er spesialisert til visse vertsplanter, mens andre arter har mange vertsplanter. I en kvadratmeter jord finnes det millioner av mikroskopiske nematoder. Også insekter angripes av nematoder, noen arter kan brukes for biologisk bekjempelse av skadeinsekter.

Sammendrag

Korncystenematoder (Heterodera spp.) er et kompleks av arter og raser med forskjellige vertsplanter og skadelighet på kornsorter. I Norge er havrecystenematoden (H. avenae) rase Ha 11, H. avenae "svensk rase Våxtorp" og rugcystenematoden (H. filipjevi) "svensk rase vest" de vanligste nematodetypene. Med støtte fra Norges forskningsråd er prosjektet "Studier av arts- og rasedifferensiering innen korncystenematode-komplekset med hensikt å effektivisere tiltak mot skader i korn " gjennomført i samarbeid mellom Bioforsk, Rothamsted Research og Sveriges lantbruksuniversitet. Hovedhensikten med forskningsarbeidet var å sikre en korrekt kjennskap til nematodeart, rase og resistensforskjell mellom kornsorter, for å kunne gi riktige tilrådinger om dyrkingsopplegg og sortsvalg for den enkelte dyrker. I prosjektet har populasjoner av korncystenematoder blitt karakterisert ved bruk av morfologi, biotester og molekylære metoder. Resultatene har dannet et grunnlag for en effektiv bekjempelse, og en inntektsøkning for kornprodusenter. I dag benytter flere produsenter resultatene i praksis.

Sammendrag

Det finnes flere nematode-arter som angriper korn. Biotester mot vanlige arter og patotyper av korncystenematoder ble gjennomført i 2005 og 2004 (Holgado & Andersson 2005). Resultatene viser til dels at flertallet kornsorter ikke er resistente mot alle forekommende arter og patogtyper, til dels at det finnes ulike grader av resistens i våre kornsorter. Bekjempelse av korncystenematoder med bruk av resistente kornsorter krever derfor kjennekap til hvilke arter og patotypere som forekommer i de enkelte feltene.

Sammendrag

Det finnes flere nematode-arter som angriper korn. Biotester mot vanlige arter og patotyper av korncystenematoder ble gjennomført i 2005 og 2004 (Holgado & Andersson, 2005). Resultatene viser til dels at flertallet kornsorter ikke er resistente mot alle forkommende arter og patotyper, til dels at det finnes ulike grader av resistens i våre kornsorter. Bekjempelse av korncystenematoder med bruk av resistente kornsorter krever derfor kjennskap til hvilke arter og patotyper som forekommer i de enkelte feltene.

Sammendrag

Cereal cyst nematodes, Heterodera spp., are recognised throughout the world as economically important parasites of cereals. The virulence status on cereal cultivars differs between and within different species of the H. avenae-complex, and several pathotypes occur among them. A survey during 1995-2005 in Norway revealed that Heterodera spp. is common throughout the country. Studies in Norway have recorded H. filipjevi and also additional and possibly new species. A number of cereal cyst nematode populations from various regions of Norway, Sweden and the British Isles have been analysed using molecular, morphological and host range studies during the last three years. Fifteen populations, of the initial group of forty, are being studied more closely. Studies using isoelectric focusing and silver staining have detected divergent populations of H. avenae. The Swedish populations Ringsåsen seemed to be identical to a population found in Australia and the Swedish population Halland shows a protein profile separate from H. avenae. DNA studies are being used to determine if these populations are new species. An assortment of cereal cultivars, based on an international collection used for resistance testing, differentiates three groups, H. avenae (pathotypes Ha 11 and Ha 12), H. filipjevi (pathotype "West"), and a population from central Norway close to H. pratensis. Knowledge of the diversity of cereal cyst nematodes and their multiplication rates on their cereal hosts is of fundamental importance for efficient control strategies involving resistant cultivars. In Norway, management based on these parameters are in operation and have increased yields and profits to cereal farmers.

Sammendrag

Cereal cyst nematodes, Heterodera spp. are known world-wide as parasites of cereals and grasses. Surveys of cereals in Norway have revealed that nematodes belonging to the H. avenae complex occur throughout the country, and that H. avenae (oat cyst nematode) is the most common species followed by H. filipjevi (rye cyst nematode). H. avenae and H. filipjevi are of economic importance in Scandinavia. H. avenae has two common pathotypes, Ha 11 and Ha 12. Work in Sweden, however, has detected the three additional pathotypes H. avenae- Knislinge, H. avenae- Ringsåsen and H. avenae- Våxtorp. These pathotypes were detected also in the Norwegian surveys. In Sweden H. filipjevi has two pathotypes, "East" and "West". In Norway, only the pathotype "West" has been detected so far. Nematode management practices must be based on the knowledge of the population dynamics, the population density required to cause economic damage, and the measures capable of reducing or keeping the population density below the threshold for economic damage. Crop rotation and the use of cultivars with resistance are important measures for controlling cereal cyst nematodes. For several years it has been known that resistance to cereal cyst nematodes may be found in some commercial cultivars, although no conscious breeding for resistance has been attempted. In 2004 and 2005 a majority of cereal cultivars on the Norwegian market were tested for susceptibility/resistance towards H. avenae pathotype Ha 11, H. avenae pathotype "Våxtorp" and H. filipjevi pathotype "West" The test program included 30 cultivars of barley, 23 cultivars of oats and 6 cultivars of summer wheat. The objective of this work was to increase our knowledge on cultivar selection for farmers. Resistance against Ha11 was found in 5 barley, 3 oat cultivars and in 1 wheat cultivar. Resistance against H. avenae pathotype "Våxtorp" was not present in barley, but 4 oat cultivars, and 1 wheat cultivar were resistant. For H. filipjevi "West" resistance was not detected in wheat, but in 6 barley and 13 oat cultivars. In Norway management systems based on careful nematode identification and good knowledge on appropriate resistant cultivars are in operation. Resistant barley is generally recommended when nematode populations are high due to its high tolerance compared to resistant oats. Farmers implementing this program have reported increased cereal yields on the average of 1000 kg /ha. It has been calculated that by implementing this program in full the county of Vestfold could make an economic gain of 800 000 " annually.

Sammendrag

Cereal cyst nematodes, Heterodera spp., are known worldwide as parasites of cereals and grasses. Surveys of cereal fields in Norway have revealed that nematodes belonging to the H. avenae complex occur throughout the country, and that H. avenae (the oat cyst nematode) is the most common species, followed by H. filipjevi (the rye cyst nematode). Both species are of economic importance in Scandinavia. H. avenae has been found in two common pathotypes, Ha 11 and Ha 12. Work in Sweden, however, has detected three additional pathotypes, H. avenae "Knislinge", H. avenae "Ringsåsen" and H. avenae "Våxtorp". These pathotypes were found also in the Norwegian surveys. In Sweden H. filipjevi has two pathotypes, "East" and "West". In Norway, only pathotype "West" has been detected so far. Nematode management practices must be based on the knowledge of the relationship between initial nematode density and yield, the population dynamics, and the measures capable of reducing or keeping the population density below the threshold for economic damage. Crop rotation and the use of cultivars with resistance are important measures for controlling cereal cyst nematodes. Several cereal cultivars with resistance to H. avenae are on the market. As to H. filipjevi, resistance may be found in some commercial cultivars, although no intentional breeding for resistance against this nematode species has been attempted. In 2004 and 2005 the majority of the cereal cultivars on the Norwegian market were tested for susceptibility/resistance towards H. avenae pathotype Ha 11, H. avenae pathotype "Våxtorp" and H. filipjevi pathotype "West". Management systems, based on careful nematode identification and good knowledge of appropriate resistant cultivars, are in operation in Norway. Resistant barley is generally recommended when nematode populations are high due to its high tolerance compared to resistant oats. Farmers implementing this program have reported increased cereal yields on the average of 1000 kg /ha. It has been calculated that by implementing this program in full the county of Vestfold could make an economic gain of 800 000 " annually.

Sammendrag

Korncystenematoder (Heterodera spp.) er et kompleks av arter og patotyper. Så langt er det i Norge påvist den vanlige havrecystenematoden (Heterodera avenae) patotype Ha 11, H. avenae svensk patotype ”Våxtorp” og rugcystenematoden (H. filipjevi) svensk patotype ”Vest”. Biotest med disse patotypene ble gjennomført i 2004 og 2005 ved Sveriges Lantbruksuniversitet i Alnarp. Tester i veksthus av 63 kornsorter viste at de fleste sortene i testen var mottakelige for Ha 11 og Ha Våxtorp. Dette var også tilfelle i tester med H. filipjevi Vest for sorter av bygg og vårhvete, mens et flertall av havresortene var mer eller mindre resistente. Resultatene viser også at det finnes flere sorter på det norske markedet som kan benyttes for å holde korncystenematodene på et lavt nivå. I bygg var Frisko, Helium Meltan, Otira og Simba resistente mot Ha 11. For Ha Våxtorp viste ingen av de testede sortene seg å være resistente. Byggsortene Antaria, Frisko, Gunilla, Iver, Pernilla og Sunnita var resistente mot H. filipjevi Vest. I havre viste sortene Sanna, Gunhild og Vital resistens mot Ha 11, og mot Ha Våxtorp var sortene Gunhild, NK98059, Sanna og Vital resistente. Mot H. filipjevi Vest var Bikini, Bessin, Gunhild, Kerstin, Liberto, Matilda, NK 98008, NK980591, Olram, Pol, Sanna, SW 98195 og Vital resistente.

Sammendrag

During the last meeting on the proposal for a new council directive on control of potato cyst nematodes (PCN) in Brussels on June 2-3, 2004, it became evident that the tests to assess resistance and partial resistance in potato to PCN and interpretation of test results differ widely in the different countries and earlier recommendations (EPPO recommendation 92/3784) were not commonly adopted in the EU. Therefore the EU commission suggested that an expert working group should review the definition of resistance of potato to PCN and outline the procedures for an appropriate test to assess resistance of potato to PCN.

Sammendrag

Soil nematodes are important components of soil ecosystems, but have so far received little attention in organic farming. Many free-living nematodes are important for decomposition and mineralization processes, and it is estimated that the nematode grassing of bacteria would mobilise up to 124 kg N ha-1yr "1. Furthermore, their feeding activities on the rhizoplane may reduce microbiological immobilisation of nitrogen. In organic farming the use of clover and other nitrogen fixating legumes is important for securing appropriate nitrogen levels. Clover is an excellent host for a wide range of plant parasitic nematodes. In organic farming damage has so far been reported for root lesion nematodes (Pratylenchus spp,), clover cyst nematode (Heterodera trifolii) and the northern root knot nematode (Meloidogyne hapla). Nematode monitoring is a prerequisite for management. Effective control measures of plant parasitic nematodes and good management systems for beneficial nematodes would allow for increasing yields and improved quality. Organic farming puts new challenges to the science of nematology, and would profit from a close interaction between nematology and soil science.

Sammendrag

A survey of cereals, carried out in 1995-2005 in Norway, revealed that Heterodera spp. are common throughout the country. Nematodes belonging to the H. avenae complex were recorded from the county of Agder in southern Norway (58.08o N) to the county of Nordland in the north (65.5o N), and this so far is the most northern location reported for Heterodera in cereals. Studies in Norway have recently recorded H. filipjevi and also additional and possibly new species. H. filipjevi is of economic importance in Scandinavia. It was first recorded in the beginning of the 1970s and then referred to as the "Gotland strain of H. avenae". Biotests carried out in Sweden demonstrated the occurrence of two pathotypes, "East" and "West", named according to their geographical distribution. In Norway H. filipjevi, was first recorded causing damage to winter rye, Compared to H. avenae, H. filipjevi has the ability of hatching easily and at low temperatures, this ability of rapid hatch suggests that field population densities could easily be underestimated if based on cyst extractions only. Hence, accurate assessments of pre-plant densities of H. filipjevi require quantification of infective juveniles in soil. Nematode management practices must be based on the knowledge of the population dynamics and the threshold levels needed to cause economic damage. Tests of 63 cereal cultivars on the Norwegian market revealed 13 oat and six barley cultivars to be resistant to H. filipjevi "West" It is important that resistant cultivars of barley are recommended when nematode populations are high, as resistant barley is more tolerant than resistant oats. However even in rotations with resistant barley the farmer should be prepared to accept some yield losses in the first year of management. One important challenge in the management of H. filipjevi is the common occurrence of mixed populations. H. avenae "sensu stricto" and/or its slightly diverging form "Våxtorp" is often found together with H. filipjevi. From our experience the dynamics of mixed populations needs a stronger emphasis in management systems for cereal cyst nematodes. Our knowledge of the occurrence and distribution of cereal cyst nematode species and pathotypes in Norway has increased, and the screening of cultivars for resistance against various populations particularly H. filipjevi, H. avenae "sensu stricto" and the "Våxtorp"-type has been intensified. Hence, today farmers can be provided with control strategies which are easily implemented. With this management system, farmers in the county of Vestfold have increased cereal yields. After 3-4 years of implementation farmers have reported yield increases averaging 1000 kg ha. Compared to the earlier situation (when control was not practiced), a full implementation of the current management program in the county of Vestfold has been estimated to give an annual economic gain in the order of "800 000.

Sammendrag

Intergert plantevern går ut på å kombinere flere ulike bekjempelsestiltak for å redusere bruken av kjemiske plantevernmidler. For å kunne utføre integrert bekjempelse, må man vite hvordan skadegjørerne ser ut, hvordan de lever og hvilke tiltak som er aktuelle. I boka finnes nærmere beskrivelse av vanlige ugras, skadedyr og sjukdommer i korn. Retningslinjer for integrert plantevern i korn finnes også i boka.

Sammendrag

Intergert plantevern går ut på å kombinere flere ulike bekjempelsestiltak for å redusere bruken av kjemiske plantevernmidler. For å kunne utføre integrert bekjempelse, må man vite hvordan skadegjørerne ser ut, hvordan de lever og hvilke tiltak som er aktuelle. I boka finnes nærmere beskrivelse av vanlige ugras i veksthus, skadedyr og sjukdommer på blomstrende potteplanter, dekorasjonsplanter, utplantingsplanter og snittblomster. Nytteorganismer som brukes i biologisk bekjempelse i veksthus blir også beskrevet. I boka er det tatt med retningslinjer for integert plantevern i snittroser, julestjerne og utplantingsplanter

Sammendrag

Korncystenematoder (Heterodera spp.) er et kompleks av arter og patotyper med forskjellige vertsplanter og skadelighet på kornsorter. I Norge viser det seg så langt å være vanlig havrecystenematode (Heterodera avenae) patotype Ha 11, H. avenae "svensk patotype Våxtorp" og rugcystenematoden (H. filipjevi) "svensk patotype vest". Biotest mot disse patotypene ble gjennomført. 37 kornsorter inngikk i testen. I bygg var Otira resistent mot H. avenae Ha 11, og det var lav oppformering i Edel og Iver. For H avenae Våxtorp populasjonen viste flere byggsorter lav oppformering uten å kunne betraktes som resistent. Byggsortene Gunilla, Iver, Pernilla og Sunita viste resistens mot H. filipjevi vest, og disse sortene viste lavere oppformering enn Baronesse. Av havre viste sorten Gunhild resistens mot H. avenae Ha 11, og Gunhild var også resistent mot H. filipjevi vest, i tillegg til at sorten viste lav oppformering av H. avenae Våxtorpspopulasjonen. Mot H. filipjevi vest finnes flere resistente havresorter. Vårhvete sorten Avans viste resistens mot både H. avenae Ha 11 og Våxtorpspopulasjonen. Mot H. filipjevi vest ble ingen resistens påvist i vårhvete. Testen viser at det finnes sorter på det norske markedet som kan benyttes for å holde korncystenematodene på et lavt nivå.

Sammendrag

Protein variability of 27 populations of cyst nematodes belonging to the Heterodera avenae complex were studied using isoelectric focusing (IEF). Sixteen Norwegian populations were compared with standard populations of H. avenae, H. filipjevi, H. mani and H. arenaria. Norwegian populations were also tested for pathotype on selected cereal cultivars. Based on differences in the protein banding pattern, eight clusters of populations could be recognised. Nine Norwegian populations grouped together with H. avenae standards. The three Swedish populations: Knislinge, Ringsåsen and Våxtorp, previously classified as H. avenae, differed from this species, from H. filipjevi and from each other. Four Norwegian populations clustered together with the Våxtorp population. Two Norwegian populations formed a cluster together with a Swedish H. filipjevi standard. The Norwegian population Brekstad differed from all other populations, as did the standards of H. mani and H. arenaria. Pathotype testing of the Norwegian populations identified ten populations as H. avenae pathotype Ha 11, while three were close to pathotype Ha 12. The two H. filipjevi populations were close to the Swedish pathotype west. The Brekstad population differed from all others also in host spectrum. This population and the Våxtorp-group demonstrate a complexity within the Norwegian cereal cyst nematodes that merits further investigation.

Sammendrag

Summary. During the years 1995 to1999 a survey was carried out to study the occurrence of Heterodera spp. in cereals in Norway. Cereal cyst nematodes were found widespread in all the principal cereal growing areas. A formerly unidentified species of cereal cyst nematode, belonging to the "Heterodera avenae complex", is recorded for the first time, heavily parasitising winter rye in the Sandefjord region. Comparative studies, including morphology, protein variability and virulence pattern, of two Norwegian populations with known Swedish H. avenae and H. filipjevi populations confirmed the presence of Heterodera filipjevi (Madzhidov, 1981) Stelter, 1984 in Norway and constitutes a new geographical record. The pathotype tests demonstrated that the two populations were closest to the Swedish pathotype "West".

Sammendrag

Morfologiske karakterer og morfometri til cyster og andre-stadie juveniler for to Heterodera filipjevi-populasjoner fra Norge ble studert og sammenliknet med publiserte data for H. filipjevi. Resultatene fra den morfologiske analysen øker variasjonsbredde til cystekarakterer. Studien gir også ny informasjon om hodets morfologi hos hunnen, cystens kutikula og vulva kjegle, likesom lateralfelt til andre-stadie juvenilen. Disse kompletterende data vil gjøre den morfologiske identifikasjonen av H. filipjevi lettere.

Sammendrag

Rotgallnematoder (Meloidogyne spp.) er globalt de mest skadelig nematodene og forårsaker mer en 10% avlingsreduksjonen på verdensbasis. M. arenaria, M. javanica, M. incognita, og M. hapla er de viktigste artene. Totalt er det beskrevet mer enn 90 arter av rotgallnematoder, og av disse er ca. 20 så langt blitt funnet i Europa. På det Europeiske kontinent er M. hapla mest utbredt, mens M. chitwoodi og M. fallax er påvist i begrensede områder. De to sist nevnte artene er karanteneskadegjørere i EU og tiltak iverksettes for å hindre videre spredning. M. chitwoodi and M. fallax betraktes som en trussel for Europa og begge artene forårsaker alvorlige kvalitetsskader på potet og grønnsaker som gulrot. M. chitwoodi og M. fallax er ikke påvist i Norge. Risikoanalysestudier med hensyn til M. chitwoodi og M. fallax, har vist at begge artene kan forventes å kunne etablere seg i Norge, og at en generasjon kan forekomme i Midt-Norge og to generasjoner i Sør-Norge. Utvikling av skade på potetknoller vil være mulig i Sør-Norge.

Sammendrag

Abstract. Soil samples from fields infected with Heterodera avenae, H. filipjevi and Globodera rostochiensis were examined for the presence of fungi on eggs and juveniles. Different levels of natural infestation of cysts by fungi were detected. Fungi belonging to the class Deuteromycota have been isolated from cereal cyst nematodes (Heterodera spp., H. avenae and H. filipjevi) and potato cyst nematode (Globodera rostochiensis). Verticillium chlamydosporium Goddard (syn. Pochonia chlamydosporia) was isolated from cereal cyst nematodes and Paecilomyces lilacinus (Thom) Samson was isolated from potato cyst nematodes. The aim of this study is to investigate the possible occurrence of microbial antagonists of cyst nematodes in Norway. This is the first report of fungi infecting cyst nematodes in Norway.

Sammendrag

Undersøkelser i 1955 – 1963 og i 1995 - 1998 har vist at korncystenematoder er vanlig i områder med korndyrkning fra Sør-Norge til Nordland 65,5ºN. Dette er det nordligste funnet av korncystenematoder som noen gang er gjort til nå. I 2000 ble det rapportert funn av H. filipjevi i Sandefjord i Vestfold i forbindelse med skade på høst rug sort Danko. I patotypeundersøkelser av H. filipjevi i Sandefjord er det funnet den såkalt ”Gotlandstypen av havrecystnematoden patotype vest”. Symptomene forårsaket av H. filipjevi er vanlige som for cystenematoder, det vil si mer eller mindre store flekker, der planten vokser dårlig, mens ugresset i stedet hevder seg godt. At kornet spirer dårlig tidlig om våren kan være et symptom på angrep av cystenematoder. Erfaringer fra arbeidet med ekstraksjon av cyster av H. filipjevi viste at denne arten klekker raskere enn H. avenae, og trenger lavere temperatur. Derfor kan det forventes at skader i høstkorn kan bli omfattende. Bekjempelse av korncystenematoder ved hjelp av resistenssorter av korn, er det viktig å vite hvilke arter og patotyper av korncystenematoder som finnes i jorda, så en kan benytte riktig kornsort.

Til dokument

Sammendrag

Ved bekjempelse av korncystenematoder ved hjelp av resistenssorter av korn, er det viktig å vite hvilke arter og patotyper av korncystenematoder som finnes i jorda, så en kan benytte riktig kornsort. Ved hjelp av resistente sorter vil nematodetettheten reduseres. Tidligere erfaring har vist at resistent bygg er svært tolerant, og kan dyrkes ved høye nematodetettheter. Det er påvist flere arter og patotyper av korncystenematoder, og per i dag finnes ingen kornsorter som er resistente mot alle disse. I Norge og Sverige har testing for å finne resistente sorter foregått frem til 1990-tallet. De siste årene har skader forårsaket av korncystenematoder økt, og i Sverige har videre testing igjen blitt nødvendig. En oversikt av sorter med resistens vises.

Sammendrag

I Norge har korncystenematode Heterodera spp.(CCN) vært kjent siden 1925. Symptomer på angrep av CCN viser seg vanligvis i felt som flekker med kortvokste planter. I Vestfold har en i alle år hatt skifter hvor det opptrer flekker med dårlig vekst i korn. Ved observasjoner av nematoderesistente kornsorter vinteren 1999, og høsten 2000 ble det undersøkt 14 jordprøver på forskjellige steder i Vestfold. Det ble funnet H. avenae og/eller H. filipjevi i 13 av prøvene. Med bakgrunn i disse undersøkelsene ble det startet et 3 årig prosjekt, "Utbredelse av, og tiltak mot korncystenematode i Vestfold". Målsettingen for prosjektet var å undersøke utbredelsen av CCN i Vestfold, og å finne tiltak for korndyrkere. Prosjektet startet i januar 2002. Det ble tatt ut 57 jordprøver hos 30 korndyrkere. I 31 av prøvene ble det funnet arter av CCN, mens det ikke ble funnet CCN i 26 av prøvene. Etter første år i nematodeprosjektet har vi erfart at CCN er en vanlig forekommende skadegjører på sandige jordarter med dårlig vekst i kornåker. I tillegg til dette ble det gjort feltforsøk hos 3 kornprodusenter (lokaliteter :Kvelde, Stokke, Sandefjord) i Vestfold. Resultatene viser forskjeller i avling og oppformering når en sammenligner de 2 cystenematodeartene.

Sammendrag

I Norge er korncystenematoder funnet i alle korndistrikter fra Agder fylkene (58,05oN) til Nordland (65,5ºN). På verdensbasis er det foreløpig de nordligste funn av Heterodera på korn. Symptomer på angrep av korncystenematoden viser seg vanligvis i åkeren som flekker med kortvokste planter. Generelt kan man se at felt som er angrepet har ujevn vekst. Symptomene kan lett forveksles med næringsmangel og ugunstig pH. Et indirekte symptom på nematodeangrep kan være at feltet inneholder unormalt mye ugras. Dårlig spiring og vekst i vårsesongen kan også indikere angrep av korncystenematoder. Skader av korncystenematoder i havre, hvete, bygg og høstrug i Norge har økt i de siste årene. Henvendelser fra produsenter har vist at problemene med korncystenematoder er større enn hva man tidligere har trodd. For enkelte dyrkere er kornavlingen på enkelte felt redusert med mer enn 50%. Selv om næringsmangel kan være en del av dette, er de observerte problemene uten tvil primært nematodeskade. I enkelte regioner er forventede avlingsøkninger uteblitt på tross av høyproduktive kornsorter, riktig gjødsling og anbefalt bruk av plantevernmidler. I gjennomsnitt er det mulig at skaden av korncystenematoder ikke utgjør mer enn noen få prosent av den totale kornavlingen i hele landet. Hvis en antar at avlingsreduksjonen er 1-5% av den totale avlingen, utgjør den årlige reduksjonen fra 2001 mellom 23 - 118 millioner NOK. Tidligere studier i Norge har påvist forekomst av Heterodera avenae patotype Ha 51. Dette studiet har vist forekomst av 2 H. avenae patotyper Ha 11, og muligens Ha 12. Studiet har også påvist forekomst av Heterodera filipjevi for første gang i Norge. Fra H. filipjevi fra Vestfold er det funnet en nærliggende patotype til den såkalte svenske "patotype vest". På verdensbasis er det foreløpig første rapport av skader av H. filipjevi på høst rug. Studiene omfatter morfologi og morfometri av 2 populasjoner av H. filipjevi. Komplementerende ny informasjon om morfologiske kjennetegn som vil lette identifikasjon er også rapportert i dette studiet. Målinger av norske individer av H. filipjevi har større variasjon hos cyster og andre juvenil stadier enn tidligere antatt. Ny informasjon om H. filipjevi som presenteres er morfologi av hode til hunnen, åser, punkter og porer i cysteskallet, distribusjon av bullae, og morfologi av lateralfelter i 2. juvenil stadium. Proteinvariasjon i 27 populasjoner av korncystenematoder var studert med hjelp av isoelektrisk fokusering (IEF). Biotest av 16 norske populasjoner ble gjort. IEF har indikert at ni norske populasjoner tilhører H. avenae sensu stricto. To norske populasjoner tilhører H. filipjevi. Dette ble bekreftet i biotest. Forekomsten av populasjoner som avviker fra de til nå kjente artene i H. avenae-komplekset er registrert. IEF har vist at fire norske populasjoner ligner Våxtorp populasjon fra Sverige. Disse populasjonene kan tilhøre en ubeskrevet art fordi deres proteinprofiler er forskjellig fra H. avenae og H. filipjevi. I tillegg kan en norsk populasjon fra Brekstad også tilhøre an ny art, da den har forskjellige proteinprofiler, morfologi og virulence i pathotypetest. Sopp som er parasitter til H. avenae forekommer naturlig i områder hvor det dyrkes korn i monokultur. I dette studiet ble den jordboende sopp parasitten Verticillium chlamydosporium Goddard (synonymous Pochonia chlamydosporia) isolert fra H. avenae, H. filipjevi og Heterodera spp. i Østfold, Vestfold og Sør Trøndelag. Det er det første rapporterte funn av jordboende sopp som parasitterer korncystenematoder i Norge.

Sammendrag

Several species of cyst nematodes in the genus Heterodera attack cereals. The most common, and maybe the most important species, is the cereal cyst nematode (CCN) H. avenae, which was first reported in Norway in 1925. The dominant cereal in Norway is barley, followed by oats and wheat. The acreage grown under wheat has increased by 70% during 1985 to1995. Field damage by cereal cyst nematode is shown as patches with uneven growth, which is most clearly seen in oats; in addition to cereals several species of grass are hosts of some cereal cyst nematodes. This report gives a background to some problems related to cyst nematodes on cereals, and is the result of a recent survey of the genus Heterodera in cereals in Norway. The results are based on the analysis of 220 samples for the years 1995-1998. Nematodes in the genus Heterodera are common in Norwegian cereal fields and have been recorded from the county of Agder in the county of Nordland. In this survey the highest frequencies of occurrence were found in oats and wheat. Earlier studies have demonstrated Ha51 to be the dominant pathotype of H. avenae in Norway. The observed increase in damage may relate to the lack of resistance of Ha51 in current cultivars, and a shift in pathotype frequency of CCN. The increased acreage of wheat and the cultivation of susceptible cereals when used as a pre-crop to oats and wheat could also contribute to the increase in damage. Knowledge of the occurrence and distribution of different species and pathotypes of cyst nematodes on cereals in Norway also needs to be developed. Screening the current cultivars for resistance against cereal cyst nematodes, and finding effective nematode pest control strategies is also urgently needed.

Sammendrag

Cereal cyst nematodes (CCN), Heterodera spp., are common pests of cereal crops in Norway. Fifteen populations were investigated morphologically, through biotests, and through electrophoretic studies, using isoelectric focusing and silver staining of proteins. In the biotest the populations were grouped by their virulence on barley differentials (resistance genes) Varde (Rha), Emir (Rha"E"), Ortolan (Rha1), KVL 191 (Rha2), Siri (Rha2) and Morocco C.I. 3902 (Rha3). Eleven populations expressed themselves as H. avenae pathotype Ha11. These were all fairly similar morphologically and electrophoretically. The biotest further suggested two populations belonging to pathotype Ha12. One of them was morphologically and electrophoretically similar to H. avenae; the other different in both respects, indicating a possible undescribed species. Two other populations appeared to be H. filipjevi, pathotype `West". One population under study was different in all aspects, morphologically, in the biotest and biochemically. Earlier studies in Norway have also indicated the occurrence of CCN pathotype Ha51. Thus, the situation in Norway regarding the CCN is very complicated.

Sammendrag

Integrert bekjempelse av nematoder har som mål å stabilisere populasjonen av viktigere planteparasittære nematoder i en akseptabel populasjonsnivå som i langsiktig perspektiver bidrar til en positiv økonomi og en sundt miljø.

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Meloidogyne chitwoodi may be introduced into Norway through plant material and soil. The nematode may easily establish on common crop plants. During the growing season two generations are expected to develop in southern Norway, while conditions in the central parts would allow for the development of one generation. M. chitwoodi starts to develop at 5ºC. Planting and sowing in Norway starts when soil temperatures reach around 4ºC. The use of plastic tunnels to increase soil temperature is a common practice in early potatoes and vegetables, and would enhance nematode development. M. chitwoodi requires 600-800 degree days (DD) to complete one generation from the time of planting, and 500-600 DD for subsequent generations. These temperature sums are commonly recorded in potato growing areas of Norway. Qualitative damage on potato tubers would require the reinfection and development of the second generation, and is expected in the southern areas. Qualitative damage on carrots does not require reinfection, and is expected also in central parts. The possibility that the nematode could cause damage to other vegetables and to cereals is an additional concern that supports its status as a quarantine pest organism.

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Service in Wageningen, The Netherlands. The smooth elongated galls, included several males, swollen adult females with protruding small egg masses and hatching second-stage juveniles. Males and second-stage juveniles also were isolated from adhering soil. The root-knot nematode was identified as Meloidogyne ardenensis Santos. Identification was based on female, male and second-stage juvenile morphology and female isozyme electrophoresis with malate dehydrogenase and esterase. Meloidogyne ardenensis is parasitizing on several dicotyledonous hosts, mostly herbaceous and woody plants and distributed throughout Europe with Scotland as the most northern report so far. To our knowledge this is not only the first published report of Meloidogyne ardenensis in Scandinavia, but also the first report of this species on lady"s mantle.

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Potetcystenematodene (PCN) Globodera spp. er opprinnelig fra fjelltrakter i Peru og Bolivia. PCN er en av de mest avanserte og fremgangsrike planteparasitter. PCN ble påvist i Europa av Kühn i 1881, og i 1923 erklærer Wollenweber den som egen art. Stone i 1973 skiller PCN i to arter. Gul PCN (Globodera rostochiensis) og hvit PCN (G. pallida). I Norge ble PCN først påvist 1955 i Agderfylkene. PCN har spredt seg raskt og i1993 ble de første funn gjort i Nord-Trøndelag. På verdensbasis er PCN funnet utbredt i 23 land og har en begrenset forekomst i 42 land, og i tillegg er det 130 land det ikke er blitt påvist enda. Både gul og hvit PCN er klassifisert som karanteneskadegjørere i 106 respektive 55 land. I de siste årene har PCN blitt påvist i Australia, Canada og USA, som på nytt satt fokus på hvor lett PCN kan spres og hvilke nasjonale konsekvenser PCN har. De plantesanitære og økonomiske konsekvensene av PCN er betydende. I EU vil PCN bli regulert i det nye EU direktivet 2007/33/EC som implementeres nå. Formålet med direktivet er å begrense og kontrollere spredningen til PCN. I direktivet gjøres det ingen forskjell mellom gul og hvit PCN, det nevnes at arealer for settepotet og planter til videre dyrking må ha en offisiell dokumentasjon om PCN status, det skal årlig gjennomføres offisiell prøvetaking av 0,5 % av arealet av felt for produksjon av annen potet enn settepotet. Smittede felt får ikke brukes til produksjon av settepotet eller planter til videre dyrking. Bekjempelsestiltak iverksettes på smittede felt som skal brukes til produksjon av annen potet enn settepotet. Ved resistensbryting skal PCN populasjonen rase testes. Det skal sendes en årsrapport til EU om tiltak som iverksettes i hvert land. I dag benyttes nematicider for å kontrollere PCN, og samtidig disponeres mye resurser for å foredle sorter med resistens. Potetprodusenter i England bruker ca. Nok. 584 mill. pr år for å sikre sin potetproduksjon. Etter siste oppdagelse av PCN i Australia har mye ressurser blitt benyttet for å utrydde PCN, da det er blitt estimert at det vi koste ca. Nok 216 milliarder i en periode av 20 år hvis PCN blir utbredt i landet. I tillegg til Australia har land som Israel, USA og Canada investert store ressurser for å utrydde PCN, da de mener at på lang sikt er dette billigere enn å leve med PCN. For å gjøre dette mulig har disse land satt i verk strenge restriksjoner. Disse restriksjonene omfatter forbud mot å dyrke potet og andre vertsplanter, benytte store menger nematicider, og prøvetaking. I USA har det 2006-2009 blitt analysert 257 700 prøver, etter påvising av hvit PCN i 9 felt i Idaho. USA har som målsetting å utrydde PCN på 7 år. Som resultat av EU:s direktiv (EC) No 1107/2009 om begrensning av giftige kjemikaler som forårsaker som forårsaker helse- og miljøproblem forventes bruket av de fleste nematicidene å være forbudt i 2015. For å imøtekomme disse utfordringene har forskere i Storbritannia startet sekvensering av hvit PCN. Det er ledet av University of Leeds, i samarbeid med Rothamsted Research, SCRI, og Sangers Institute, og har et budsjett av Nok 15 mill. Det forventes at dette kan gi nye bærekraftige alternativer til bekjempelse av PCN. I tillegg bruker andre Europeiske land ressurser på å finne alternativer for bekjempelse med fangevekster og biofumiganter. I det fleste land omfatter bekjempelse i dag bruk av nematicider, bruk av sertifisert settepotet, og kontrollert bruk av resistente sorter for å unngå oppformering av resistensnedbrytende raser. I tillegg har de et karanteneregelverk. Dette bidrar til en lønnsom potetproduksjon.

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Flere arter cystenematoder (rundormer) i slekten Heterodera angriper korn. Den vanligste og kanskje viktigste arten er havrecystenematoden H. avenae (CCN) som har vært kjent i Norge siden 1925. Korndyrkingen i Norge domineres av bygg fulgt av havre og hvete. Hvetearealet har i perioden 1985-1995 økt med 70%. Feltskader av CCN vises som flekker med ujevn vekst, hvilket er særlig tydelig i havre. I tillegg til korn er flere arter av gras også vertsplanter til CCN. Det presenterte arbeidet gir en bakgrunn for problematikken omkring cystenematoder i korn, og rapporterer om utbredelsen av slekten Heterodera i kornfelt i Norge. Resultatene bygger på 218 prøver analysert i perioden 1995-1998. Nematoder i slekten Heterodera er registrert fra Rogaland til en posisjon 65,5oN i Nordland. Havre og hvete viser de høgste forekomstene. Det er notert et økt skadeomfang de senere årene. Tidligere studier har vist at CCN patotype Ha 51 har dominert i Norge. Et økt skadeomfang kan skyldes at resistensen mot Ha 51 ikke er vedlikeholdt i nyere sorter, og at det er en forskyving av patotype-spektret innen CCN. Et økt hveteareal og dyrking av mottakelig korn før havre eller hvete kan også være medvirkende årsaker. Kunnskapen om dagens art- og patotype-spekter blant korncystenematodene i Norge må økes. Det er viktig å kartlegge forekomst av resistens mot cystenematoder i dagens kornsorter, og utvikle strategier for en effektiv bekjempelse.

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Nematodes (roundworms) are microscopic vermiform animals. Most nematodes live in soil or in fresh water and marine sediments. Nematodes (Phylum Nematoda) has experienced more than 600 million years of evolution and form 80% of the multicellular animals on planet earth. The population densities of nematodes often reach several million individuals per m2. Most species are free-living, feeding on microorganisms, microscopic plants and animals. Numerous species, however, are parasites of humans, animals and plants. Nematodes may be beneficial to man as regulators of nutrient cycling or as parasites of insect pests. The study of plant parasitic nematodes, nematology, is a young scientific dicipline. Although, the first plant parasitic nematode, i.e. the wheat seed-gall nematode Anguina tritici, was observed as early as in 1743, nematology as a science did not develop until the second half of the 19th century. The economic impact of nematodes as parasites of agricultural crops was recognised as late as in the 1940:ties, and was a consequence of the increased use of chemicals. The economic loss caused by nematodes to world agriculture may amount to 80 billion US$ annually. Plant parasitic nematodes are of particular importance in tropical and subtropical regions of the world. At present the full importance of these parasites may be much underestimated due to the frequent use of nematicides. However, as a result of future restrictions in the use of chemical treatments against nematodes, the damage caused by these parasites can be expected to increase dramatically. Future successful management of both harmful and beneficial nematodes would require increased knowledge of nematode biology. This can only be achieved by an increased research and education in nematology.

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Cereal cyst Nematodes Heterodera spp. are pests of cereal crops, and their occurrence is known for many years both in Europe and in Norway. This group of nematodes forms a complex of species referred to as the "Heterodera avenae-complex", this includes H.avenae Wollenweber (CCN), H. bifenestra Cooper, H. mani Matthews, H. iri Matthews, H. hordecalis Andersson, H. latipons Franklin and H. filipjevi Krall. The host status of cereal cultivars differs between and within different species of the H. avenae-complex, and several pathotypes occur in several species. The border lines for species and pathotypes of the Heterodera avenae-complex are diffuse. Several pathotypes of CCN are found in Europe, and two pathotypes Ha51 and Ha11 are reported from Norway, Symptoms of damage by cyst nematodes in cereals are usually shown as patches of pale and stunted plants. The effects on the aerial parts of plants are identical with symptoms of severe nitrogen and other mineral deficiencies. Plants attacked by the nematodes wilt readily in dry weather. This reflects the nematode damage to the root system. In our experience most modern commercial varieties of cereals are equally susceptible to CCN. The aim of the project is to study the occurrence and distribution of the species within H. avenae-complex, to clarify the pathotype spectrum and to investigate the possible occurrence of microbial antagonists in Norway. The project is expected to be completed in 2001.

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Soil samples from a growth depression in potato (cv. Saturna) yielded large numbers of root lesion nematodes Pratylenchus penetrans. Growth was greatly reduced in the center of the patch, but improved gradually towards the margins. Transect-sampling showed plant growth to be negatively correlated with densities of P. penetrans. The nematode density in the central part of the patch was 900/250g of soil, compared to 49/250 g of soil in the margins, where plant growth seemed unaffected. Our data suggest a threshold for damage of 100-250 P. penetrans per 250 g of soil. P. penetrans was present in roots, underground stems, stolons and tubers. In tubers nematodes occurred in the outermost 0.5 mm of the tissue. Common scab (Streptomyces spp.) occurred frequently, and P. penetrans was also present in tubers with scab. The nematodes were found around and inside cross-fissure lesions considered typical of Streptomyces. Saturna has a relatively high degree of tolerance against common scab. The high frequency of scab, and close association of the nematodes with the symptoms could indicate an interaction. This study suggests that Norway may have a new problem in potato production. Our study confirms that P. penetrans survives storage of seed potatoes, from which new infestations develop. Hence, tubers do appear to be an important means for the spread of P. penetrans to new areas.

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I forbindelse med prosjektet «Internasjonal handel med grøntanleggsplanter og spredning av skadegjørere» ble det gjort undersøkelser for planteparasittære nematoder. Totalt ble 110 planteprøver fra Danmark, Nederland, Polen, Tyskland, Ungarn og Norge undersøkt med hensyn til nematoder som er nevnt på A- og B-liste, og i «Forskrifter for statskontrollert produksjon». Rotgallnematoder og cystenematoder ble ikke funnet i prøvene. Bladnematodene Aphelenchoides fragariae ble funnet på Astilbe, A. rizemabosi på Saxifraga og A. blastophthorus på Saxifraga og Hermerocallis. Rotsårnematoden Pratylenchus penetrans ble funnet i prøver med Astilbe, Calluna, Rosa, Saxifraga og Thuja. Dolknematoder Xiphinema ble funnet på Mahonia. Stubbrotsnematoder fam. Trichodoridae ble funnet på Cavanga Chamecyparis, Juniperus, Mahonia, Phlox, Picea, Rhododendron, Rosa, Taxus og Thuja. Nålnematoder Longidorus ble funnet på Thuja. Andel prøver smittet med blad-nematoder viste ikke noen forskjell mellom utenlandsk og innenlandsk materiale. For rotsår-nematoder hadde Norge en høgre andel smittede prøver enn andre land totalt. Prøver med funn av virusvektorer (Xiphinema, fam. Trichodoridae og Longidorus ) utgjorde en høgre andel av det impoterte materialet enn av det norske. Resultatene viser at planteparasittære nematoder følger plantskoleplanter, både norske og utenlandske, og at det dermed er et betydelig potensiale for også å spre nye arter og raser av skadegjørende nematoder med plantskolevarer. Langsiktighet og sikkerhet i produksjonen krever bevissthet om, og forståelse for, nematodeproblematikk blandt såvel produsenter som i omsetningsledd. Jevnlig prøve-taking for å analysere for nematoder er viktig for å oppretholde nødvendig sikkerhet.