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.
2011
Forfattere
Gunda Thoeming H. Saucke Geir Kjølberg KnudsenSammendrag
The pea moth Cydia nigricana (Lepidoptera: Tortricidae) is a major pest in pea growing areas. Alternative pest control techniques are needed since efficient control options are scarce. A strong correlation between the seasonal flight period of C. nigricana and the phenology of the pea plant Pisum sativum (Fabaceae) has been shown in field studies in Northern Hesse, Germany, in the years 2006 – 2008. In continuative studies we are investigating the olfactory space between pea moth and pea plant, intending the identification of volatile cues encoding host recognition and host finding in pea moth females, and the use of these volatile compounds for the pest management of the pea moth. In two-choice experiments in insect cages the preference between potted pea plants of different phenological development stages were tested, using male and female C. nigricana (mated and non-mated). Mated females clearly prefer flowering pea plants, whereas, non-mated females and males showed no preference. In wind tunnel experiments the upwind orientation of C. nigricana towards the odour of pea plants of different phenological development stages were tested, using potted pea plants (A) and headspace collections of pea plants (B) as odour source. In both wind tunnel set ups (A and B), the preference of mated females for the pea flower has been confirmed and additionally, high attraction of mated females for the late bud stage was recorded. Overall, the flower and the late bud stage of P. sativum seem to be the most important phenological development stage for the host finding behaviour of C. nigricana. In ongoing studies we are identifying and characterising the behavioural active volatile compounds of the pea plant, using GC-MS (coupled gas chromatography – mass spectrometry) and GC-EAD (coupled gas chromatography – electroantennographic detection).
Forfattere
Christer MagnussonSammendrag
In the Nordic countries the total forest area is 67 million hectars, with conifers covering 38 milllion hectars. The Nordic standing crop of conifer wood is about 5 million m3, with an almost equal share of pine (Pinus sylvestris) and spruce (Picea abies). Because of this large and precious forest resource, the recent spread of pinewood nematode (PWN) Bursaphelenchus xylophilus in Europe is of great concern to Nordic countries. The expression of pine wilt disease requires summer temperatures higher than normal for Scandinavia. However, in the area of the recent outbreak in Galicia in Spain, temperatures seem modest, with mean values for July and August at or just above 20oC. Climate change may push the Nordic area into warmer conditions. Available models suggest that damage to Nordic forests is expected to be small in a 50 years perspective. Long-term models are scarce, but in view of pine tree production cycles of up to 120 years, mortality may occur more frequently within one or a few forest generations. Since PWN may exist in trees free of wilt symptoms its distribution in Europe becomes unclear. Monitoring of the pest in Nordic forests requires sampling of cutting waste with signs of activity from vector insect in the genus Monochamus. In the Nordic area more than 9000 samples have so far been analyzed from risk areas and risk commodities. A recent simulation PWN spread in Norwegian forests indicates that 14 years may elapse before detection by the present level of 400 samples annually. We are convinced that large sampling volumes and strict import regulations are vital strategies for keeping the Nordic area free from PWN.
Forfattere
Ricardo Holgado Christer MagnussonSammendrag
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
Organic fields are often assumed to have less pests and more beneficials than conventionally managed fields. We monitored 12 Norwegian strawberry fields, six organic and six conventional, by sampling leaves two times per year in 2002-2003. Young folded leaflets were visually inspected for eggs and adult females of strawberry mite (Phytonemus pallidus fragariae), and mature leaves were used for extraction of mobile stages of two-spotted spider mite (Tetranychus urticae). The spider mites were examined for infection of the mite-pathogenic fungus Neozygites floridana. Predatory mites (Phytoseiidae) were recorded on both leaf types, and the females mounted and identified. Soil was also sampled from each field, to study the natural occurrence of entomopathogenic nematodes. All samples were taken 0-13 metres from the border vegetation. Both pest mites tended to be more abundant in conventional than in organic fields, while the number of phytoseiid mites was very low in both growing systems. Nevertheless, three phytoseiid species were recorded for the first time in Norway: Amblyseius rademacheri Dosse, Neoseiulus kodryensis (Kolodochka) and Neoseiulus reductus (Wainstein). N. floridana infection found in T. urticae females varied from 0-19%, and was higher in 2002 than in 2003. The fungus was recorded at least once in all 12 fields, and there was no consistent difference between the two growing systems. In 2002 there was a significant negative correlation between % T. urticae with N. floridana hyphal bodies found in the first sampling and the number of T. urticae present in the second sampling about four weeks later. Beneficial nematodes (mostly Steinernema) tended to occur in more of the organic than in the conventional soil samples. To sum up, both pests (T. urticae and P. pallidus) and one of the beneficial groups (entomopathogenic nematodes) seemed to conform to the expected difference between organic and conventional fields. There are many possible mechanisms related to the differences in pesticide and fertilization regimes that could lead to such a pattern. For the two remaining beneficials (N. floridana and Phytoseiidae) we could not find a consistent correlation between abundance and growing system.
Forfattere
Harald Volden Harald VoldenSammendrag
Fôropptaket hos storfe er i hovedsak bestemt av: 1) dyrets inntakskapasitet (IC), kvaliteten på grovfôret og 3) samspillet mellom grovfôr og kraftfôr. Det sistnevnt er først og fremst best av substitusjonseffekten, dvs. hvordan kraftfôrmengden reduserer opptaket av grovfôr. Hos voksende storfe er IC regulert av dyrets vekt og tilvekst. Egenskaper ved grovfôret er først bestemt av egenskaper som fordøyelighet, fiber innhold (NDF), gjæringskvalitet og partikkelstørrelse. I NorFor er surfôrets potensiale for foropptak bestemt av fylleverdien (FV) som er beregnet ut fra fordøyeligheten av organisk stoff (OMD), NDF innholdet og innholdet av gjæringsprodukter, bestemt som totale syrer og ammoniakk. I Norge er timotei den viktigste grasarten og den kjennetegnes ved god smaklighet, og høy fordøyelighet og god fiberkvalitet når den høstes ved et tidlig til middels utviklingsstadium. En svakhet ved timotei er imidlertid at den har dårlig holdbarhet ved et intensivt driftsystem dvs. flere høstinger. Raisvingel er et interessant alternativ til timotei i et intensivt driftsystem da den bedre tåler flere høstinger og har en næringsverdi som ser ut til å være på høyde med timotei. Raisvingel sorten Felina har i tidligere studier vist seg å være en interessant fôrvekst basert på dens overvintringsevner. Imidlertid har det vært reist spørsmålstegn ved smakeligheten til raisvingel. Ut fra det vi kjenner til er det ikke gjennomført fôringsforsøk med okser hvor timotei og ulike sorter av raisvingel er sammenlignet for å studere effekten på tilvekst og fôropptak. Formålet med denne undersøkelsen var å sammenligne timotei (Phleum pratense ) sorten Vega, med X-Festulolium sortene Felina (Lolium multiflorum x Festuca arundinacea) og Felopa (Lolium multiflorum x Festuca pratensis ).
Sammendrag
Tracers can be used to monitor emisions of leachate from landfills, in order to detect hydrological pathways and to evaluate environmental pollution. We investigated the occurrence of the stable carbon isotope ratio (13C measured in dissolved inorganic carbon, or d13C-SCO2) and tritium (3H), in addition to parameters commonly found in relatively high concentrations in leachate such as chloride (Cl), organic matter (COD), nitrogen (Total and NH4-N), iron (Fe), electrical conductivity and pH. The sampling was performed at seven landfills in the south-eastern part of Norway during a period of 5 years. The objective was to evaluate the potential for tracing leachate in the environment with emphasis on groundwater pollution. By analyzing the d13C-SCO2 ratio in leachates, ground waters and surface waters the influence of leachate can be identified. The content of d13C-SCO2 varied from -5.5 to 25.9‰ in leachate, from -25.4 to 14.7‰ in groundwater, and varied between -19.7 to -13.1‰ in creeks. A comparison of the content of carbon isotope ratio with the concentrations of the compounds COD, electrical conductivity, Total- and NH4-N, Cl and Fe showed that d13C-SCO2 is a good tracer for leachate due to higher sensitivity compared to other parameters. The mean concentration of all the studied parameters was higher in the leachate samples, however, only the carbon isotope ratio showed significant differences between all of the groups strongly and weakly polluted and unpolluted samples, showing that it can be used as a practical tracer for lechate in groundwater and surface water. The carbon isotope ratioshowed strong correlation between nitrogen and electrical conductivity, and bicarbonate, but not with pH. Tritium was only found sporadically in low concentrations and is considered not suitable as a tracer at the sampled locations.
Forfattere
Marianne StenrødSammendrag
Pesticides in Norwegian streams and rivers have been monitored since 1995 through JOVA - the Norwegian Agricultural Environmental Monitoring Program. During these years the regulatory authorities have implemented measures to minimize the risk for pesticides entering the water bodies. Streams and rivers in selected agricultural drainage basins in intensively cropped areas have been sampled (volume proportional mixed samples and/or point samples) through the period withoutsoil frost and analysed for pesticide residues. Trend analyses of the monitoring data have been done to establish whether there have been reductions in the retrieval of pesticides. The indicators used include: (1) Frequency of pesticides detection, (2) Sum concentration of all individual pesticides in each sample, (3) Environmental risk by weighing the concentration of each pesticide against the environmental maximum residue limits (MRL). Monitoring results and trend analyses for the time period 1995-2010 will be presented at the conference. Preliminary interpretations of the results indicate that developments in streams and rivers show both positive and negative trends regarding the different parameters studied. Through the monitoring period there have been shifts in the trends in some of the drainage basins, from an initial positive trend to a slightly negative trend. None of the study areas do however show an increase in pesticide loads to rivers and streams, which is good considering the increase in number of pesticides analysed for and the reduction in detection levels. In total, the monitoring results indicate reduced pesticide loads, but variations in climatic conditions govern the use and retrieval of pesticides.
Sammendrag
Luserne (Medicago sativa L.) er ein fôrvekst med stort avlingspotensial, og tilpassa sortar greier seg godt i låglandet i Sør-Norge. Luserne krev god jordstruktur og høg pH i jorda for å trivast, og frøet må smittast med rett type bakteriekultur før såing. Nitrogenfikseringa kan bli høg der arten trivst. Fôrverdien er høgast på ungt stadium, og energiverdien går raskt ned med aukande stengelutvikling. Proteinverdien er generelt høg. Norsk foredlingsmateriale er meir hardført enn utanlandsk plantemateriale, og nye foredlingslinjer (LøLu9822, LøLu9823) har gjort det betre i forsøk enn sorten "Live". Linja LøLu9821 ser ut til å vera mest hardfør. I forskingsrådprosjektet "Engbelgvekstar - dyrking - klima" blir ulike lusernelinjer prøvt i utkanten av mulig dyrkingsområde, og dyrkingsteknikk til luserne blir nærmare undersøkt på Bioforsk-stasjonane Apelsvoll, Løken og Tjøtta.
Forfattere
Susanne Friis PedersenSammendrag
Tomat (Lycopersicon esculentum) tilhører søtvierfamilien, Solanaceae, sammen med andre planter som paprika, potet, aubergine og chili. Navnet “lycopersicon” er gresk og henviser til lukten og til det røde fargestoffet, lycopen, som tomaten utvikler, når den modnes. Tomaten kom til Norden for ca. 300 år siden og har vært dyrket i Norge i godt og vel 100 år. Det er god grunn til å dyrke tomat: Tomat inneholder mye vitaminer, særlig C-vitamin, men også A-, B- og E-vitamin. Den er kilde til mineraler som kalium og fosfor. Dessuten har innholdsstoffer, som lycopen og flavonoider, en forebyggende helseeffekt. Dyrking kan starte med eget oppal av småplanter eller det kan kjøpes småplanter til utplantning. Utover oppstarten er det nødvendig å vite noe om klimastyring, gjødsling og vanning, stell av planter og plantevern. Disse temaene beskrives kort her. Avslutning av kulturen med høst og lagring er det siste punktet, som også er vesentlig i tomatdyrking. Det kan man lese om her.
Forfattere
grete h m jørgensen K. M. BøeSammendrag
Housing of horses in Norway - an overview Grete H.M. Jørgensen1 and Knut E. Bøe2 1Bioforsk, National Institute for Agricultural and Environmental Research, Tjøtta Norway2Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, UMB, ås Norway Corresponding author: +47 40 76 67 69 e-mail grete.jorgensen@bioforsk.no Similar to the National regulations for cattle, poultry and pigs the Norwegian regulation for the welfare of horses also states that horse owners should facilitate social contact for their horses. Nevertheless, it is quite common that horses are kept individually or even isolated from others throughout the year. Chronic obstructive pulmonary diseases are an increasing problem in the horse population and bad air quality in stables may contribute largely to this disease. Stables with fewer than ten horses do not have to register with the National Food Safety Authorities, and a public register of stables is not available. The aim of this study was therefore to provide an overview of the current management and living conditions for trotting horses in Norway. We wanted to focus both on the outdoor and indoor environment and investigate which ventilation systems that are commonly used in stable buildings. With help from the National Trotting Association (DNT) we sent out a questionnaire to members of their local branches in order to ensure answers from all areas of Norway. In each local branch we selected four to five stables after the following criteria: one small stable with 1-2 horses, to or three medium sized stables with 3-10 horses and the largest stable in that area. The questionnaire consisted of 32 questions divided into four subcategories: management, stable environment, ventilation and outdoor areas and paddocks. 275 (61%) of the 442 initial questionnaires were returned. Seven of these were however disregarded due to incomplete answers. The results were therefore finally based on 268 stables, 38 small stables (1-2 horses), 164 medium sized stables (3-10 horses) and 60 large stables (>10 horses). The data included over 2400 horses. More than half of the stable buildings had earlier been used for other purposes (56.4%). The majority of the stable buildings were insulated (83.6%), while a few had non-insulated stables (10.1%) or shelters with three walls and a roof (1.1%). Most stables had mechanical ventilation with a fan (49.6%), while 38.4% indicated that their stable had natural ventilation. Among the stable owners that indicated having natural ventilation in the stable, only 23.1% (8.9% of all stables) had non-insulated buildings and ventilation through adjustable openings, while 76.9% (29.8%) had insulated buildings and ensured airflow through opening doors and windows. A total lack of ventilation was indicated by 4.9% of the stable owners while 0.4% did not know what type of ventilation the stable had. In addition to this, 2.6% of the stable owners had most of their horses in 24 hour loose housing outdoors with open shelters and a ventilation system was therefore not necessary. Individual housing in boxes indoors dominated (84% of all stables), while very few horses were kept in outdoor boxes (1.1%). Other housing methods were tie-stalls 1.5%), 24 hour loose housing outdoors (3.4%), both tie-stalls and individual boxes (6.0%) and tie-stalls or boxes combined with group housing or several horses in the same box (1.1%). Six of the 38 small stables had only one horse which consequently was kept alone, while 34% of the small stables kept their horses in separate paddocks. Only 15% of the medium sized stables kept the horses in individual paddocks and 80.4% kept two or more horses together during turn-out. Ninety percent of the large stables indicated that they allowed two or more horses to share paddocks during turn-out. In conclusion, Norwegian trotting horses are mainly housed in individual boxes indoors and many stables have a ventilation system that does not work properly. Most trotting horses have access to a paddock or pasture on a daily basis. Housing and management of horses in other disciplines should also be investigated.