Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2008
Forfattere
Sonja KlemsdalSammendrag
Det er ikke registrert sammendrag
Forfattere
Ricardo Holgado Anette Stryken Christer Magnusson Irene Rasmussen Kari-Ann Strandenæs Bonsak HammeraasSammendrag
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.
Forfattere
Ricardo Holgado Anette Stryken Christer Magnusson Irene Rasmussen Kari-Ann Strandenæs Bonsak HammeraasSammendrag
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.
Forfattere
Peder LombnæsSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Sonja KlemsdalSammendrag
The detection and quantification of plant pathogens in soil can be used to predict the risk to develop disease in the crop. Knowledge of the presence of such pathogens can also be used to plan control strategies for plant disease. The detection of carrot pathogens will be used as and illustrating example. Quality of carrots is influenced by several pathogens. In Norway the carrots are usually harvested in October, and while some carrots are used for immediate consumption, most carrots are stored shorter or longer periods in cold storage. During this storage there may be up to 70% loss due to carrot-rot caused by fungal diseases. The most important of these diseases are liquorice rot caused by the fungus Mycocentrospora acerina and crater rot caused by Fibularhizoctonia carotae. A standard PCR-based assay has been developed that enables us to detect the pathogens in the soil attached to the carrots at harvest. The results from this assay can be used to decide whether the harvested carrots can be stored or rather should be consumed immediately. Another disease, cavity spot, is worldwide considered to be one of the most economically important diseases of carrot. Multiple Pythium species are the cause of cavity spot and the importance of each species have been found to differ from one country to another. Five species of Pythium are the most important in causing cavity spot in Norway: P. violae, P. sulcatum, P. sylvaticum, P. intermedium and what is believed to be a new species, given the preliminary name P. "vipa". We have established standard PCR assays for the detection of all these five Pythium species in soil. These diagnostic assays have also been further developed to allow quantitative detection of these same pathogens by real-time TaqMan PCR. Such a test can potentially be used to analyze fields in order to avoid cropping carrots where the corresponding pathogens are found and the consequent risk of developing cavity spot is high. Another potential benefit for such a test might be to use the test result from a growing field of carrots to predict the need to spray this field with pesticides. The general experience is that it is difficult to extract "good" DNA from soil samples, and inhibition of the PCR reaction is often observed. DNA extraction protocols often need to be optimized to reduce the amount of compounds that otherwise would inhibit PCR, e.g. humic acid, as much as possible. Additional purification steps, dilution of the DNA samples and an adjusted mastermix might reduce the problems. Strategies to improve the PCR-based detection of plant pathogens in soil will be discussed.
Forfattere
Arvid Steen Turid Strøm Aksel BernhoftSammendrag
Background Selenium is part of the antioxidant defence system in animals and humans. The available selenium concentration in soil is low in many regions of the world. The purpose of this study was to evaluate the effect of organic versus inorganic selenium supplementation on selenium status of ewes, their lambs, and slaughter lambs. Methods Ewes on four organic farms were allocated five or six to 18 pens. The ewes were given either 20 mg/kg inorganic selenium as sodium selenite or organic selenium as selenized nonviable yeast supplementation for the two last months of pregnancy. Stipulated selenium concentrations in the rations were below 0.40 mg/kg dry matter. In addition 20 male lambs were given supplements from November until they were slaughtered in March. Silage, hay, concentrates, and individual ewe blood samples were taken before and after the mineral supplementation period, and blood samples were taken from the newborn lambs. Blood samples from ewes and lambs in the same pens were pooled. Muscle samples were taken from slaughter lambs in March. Selenium concentrations were determined by atomic absorption spectrometry with a hydride generator system. In the ANOVA model, selenium concentration was the continuous response variable, and selenium source and farm were the nominal effect variables. Two-sample t-test was used to compare selenium concentrations in muscle samples from the slaughtered lambs that received either organic or inorganic selenium supplements. Results In all ewe pens the whole blood selenium concentrations increased during the experimental period. In addition, ewe pens that received organic selenium had significantly higher whole blood selenium concentrations (mean 0.28 "g/g) than ewe pens that received inorganic selenium (mean 0.24 "g/g). Most prominent, however, was the difference in their lambs; whole blood mean selenium concentration in lambs from mothers that received organic selenium (mean 0.27 "g/g) was 30% higher than in lambs from mothers that received inorganic selenium (mean 0.21 "g/g). Slaughter lambs that received organic selenium had 50% higher meat selenium concentrations (mean 0.12 mg/kg wet weight) than lambs that received inorganic selenium (mean 0.08 mg/kg wet weight). Conclusion Organic selenium supplementation gave higher selenium concentration in ewe and newborn lamb blood and slaughter lamb meat than inorganic selenium supplementation.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Veikanter langs dyrka mark er ofte svært næringsrike. En del gjødsel vil alltid havne i kanten, enten på grunn av unøyaktig spredning eller ved tilsig og avrenning fra det dyrka arealet. Planteartene som vokser i slike veikanter er ofte problematiske ugras, slik som hundekjeks. Forsøk med slåttetiltak som kan redusere innslaget av hundekjeks og andre problematiske arter i næringsrike veikanter har blitt gjennomført siden 2004 på Fosen i Sør-Trøndelag. Prosjektet er finansiert av Statens vegvesen og flere kommuner på Fosen. Prosjektet gjennomføres i et samarbeid mellom Fosen Forsøksring og Bioforsk Midt-Norge og avsluttes i 2009. Prosjektet "Slått av næringsrik veikant" ble starta opp i 2004.
Sammendrag
Rapporten beskriver bevaringsmål og metodikk for overvåkning av restaurerings og skjøtselseffekter i Rinnleiret naturreservat, Levanger kommune i Nord-Trøndelag. Rapporten gir også foreløpig status og resultater av overvåkningen.