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.
2005
Sammendrag
Kombinasjonen av Stratego og Stereo i hel og halv dose og til forskjellige sprøytetider er prøvd ut. De høyeste avlingene ble oppnådd ved to gangers behandling, men det var én behandling ved BBCH 45 som gav det beste økonomiske utbyttet både i 2004 og i sammendrag over to år og Stratego var et hakk bedre enn Stereo. Brutto avlingsresultat var litt bedre ved å bruke en hel dose, men en halv dose gav likevel et bedre økonomisk utbytte. En hel dose Stereo alene ved BBCH 32 gav negativt utbytte for sprøyting.
Forfattere
Helge Bonesmo Anne Kjersti BakkenSammendrag
Morphology and phenology, including stolon disintegration, of white clover were studied at two sites during three years after sowing. The plants reached their maximum size in late summer in the first year after sowing, and the populations contained at that time mainly taprooted plants. The later fragmented plants were smaller in most of the investigated characteristics. A function for daily transition rate from taprooted to fragmented plants related to daily mean temperature is presented. Deviations between the recorded and the calculated proportion taprooted plants were small; the overall root mean square error was 5.7 % units. Our data indicated that there is a low temperature requirement that must be met prior to onset of transition. We also suggest that in further modelling of white clover temperature responses, the effect of day length should be accounted for, especially if the data are collected from sites with a considerable latitudinal spread.
Forfattere
Christian E. MongSammendrag
The strategy for genetic conservation in Norway aims to manage existing adaptions and thus secure each species\" ability to adapt to environmental change and to evolve. The main aims of this report are three-fold:register the regeneration of lime/linden Tilia cordata Miller in three regions of Southern Norwayidentify factors influencing regenerationsuggest means to secure a sustainable management of this species. A total of 27 sites were studied in the eastern, southern, and western regions of South-Norway. Environmental variables were sampled from 217 genets of lime. The topography was categorised, shoots (shorter than 137 cm above grond) counted, and the diameters of all stems (taller than 137 cm) measured. A search was made for seedlings at every site.Of the adult limes, 53% were rooted in ground sloping more than 30 in topography classified as scree or precipice. There was a positive assosiation between clonal regeneration, expressed as number of stems per genet, and steep terrain. The populations of lime in Southern Norway may thus be the survivors after more extensive forests 5-6000 years before present.By looking at frequencies of stems per diameter class, after an approach by Leak (1965), one may evaluate population dynamics based on data collected from one season only. According to this approach the populations for all three regions are evaluated as stable or growing in the sense that the density of stems per genet may be increasing.Only 11 seedlings of lime were found. These were all found in the climatically warmest parts of the country, in southern Vest Agder and inner parts of Oslofjorden. Most of them had established in dense vegetation on relatively level ground. Hence, different factors may govern sexual and clonal regeneration - and steep terrain does not seem to be a part of the regeneration niche of seedlings.A series of studies from Great Britain demonstrate that lack of sexual regeneration in lime is attributable to low temperatures. Fruits collected in northern England and Scotland are unfertilise because the pollen tube does not grow into the stigma in the prevailing climate of that region.Many parts of South-Norway have comparable temperatures during the flowering season of lime. Based on fruit collections from three years in Sogn og Fjordane, in 1994, 1995, and 2004, there is evidence that at least some years fertilisation takes place and some embryos develop. Still, temperature is the most plausible factor that may limit the sexual regeneration of lime in South-Norway - many of the embryos have not ripened properly, indicating a too short growing season.The importance of this factor should be further studied by germination experiments. In addition to germination tests, mapping of genetic variation both at the within and at the between stand level of lime is recommended to ensure a sustainable management can be given to lime in Norway.
Forfattere
Marcel van Oijen Mats Høglind Hans Martin Hanslin Nick CaldwellSammendrag
Previously, the literature on the growth of timothy (Phleum pratense L.) in Scandinavia was reviewed and a simple process-based model was developed to explain and predict the response of this species to different environments and management regimes. The model could not be tested in detail, because only biomass data were available at the time. However, recent experimental work has generated a large (n = 633) and uniquely detailed dataset on the growth and underlying physiology of timothy and its response to cutting at different growth stages. The present study aimed to use this dataset to test the model, and to use the model to identify the key physiological and morphological mechanisms that determine the regrowth rate of timothy after cutting. Model testing consisted of comparing simulations and measurements for eight variables: biomass, leaf area index (LAI), tiller and leaf density, rates of leaf appearance and elongation, carbohydrate concentration, and specific leaf area. Although the new data referred to a different cultivar, a different site, and different years from those used in the original model parameterization, the model was still able to account for nearly half the variation in the dataset [r2 = 0.468, normalized root mean squared error (RMSE) = 0.631]. This suggested that the key assumptions of the model (i.e., dependence of growth and allocation on the source-sink balance of the plants and a dose link between tillering and leaf area dynamics were plausible. However, the original model was not able to account for the observation that cutting at early heading tended to be followed by a longer lag phase than cutting at anthesis. We identified six mechanisms, not previously incorporated in the model, that improved its behavior: (1, 2) dependence of tillering and leaf appearance rate on carbohydrate concentration, (3, 4) dependence of leaf appearance and leaf elongation rate on plant phenological stage, (5) sprouting of new tillers from decapitated generative tillers, and (6) proportionality of the number of elongating leaves with tiller size. Incorporation of these mechanisms, followed by reparameterization using a Metropolis-Hastings Monte Carlo method, improved performance statistics (r2 = 0.521, normalized RMSE = 0.415) and explained the long duratjon of slow growth after early cutting. These mechanisms may thus be keys to understanding timothy regrowth.
Sammendrag
Plant production in northern countries is hampered by a short growing season. In Norway, waterpower provides relatively cheap and renewable energy that can be used for artificial lighting. Light is often the limiting factor for plant growth and productivity in greenhouses, and the use of artificial radiation became already early last century an important subject for investigation in Norway. Development of different lamp types gave rise to investigations of light quality on plant performance. Artificial irradiation was primarily confined to plant propagation. Large-scale irradiation of entire crops started in Norway in 1989 and has given rise to a marked increase in winter production of flowers and vegetables. The Norwegian Crop Research Institute performs applied research in all chains of plant production. Research on greenhouse production is coordinated from Særheim Research Centre. Særheim is located in the southwest of Norway where 80% of tomatoes and 50% of the Norwegian cucumbers are produced. Research on the use of artificial light for cucumber production started here in 1990. After that, production systems for lettuce, herbs, strawberry, tomato and sweet pepper were developed. Growers that nowadays use our system for year-round production of cucumbers have increased their yield from 40 to 160 kg/m2. In 2004, we were the first to reach an annual yield of 100 kg/m2 in tomato. In our applied research, consumer and wholesaler demands define the quality aspects of food to be produced. Consumers increasingly demand save and healthy food of high quality. At Særheim Research Centre, effects of environmental conditions (light, temperature, CO2, air humidity, nutrients, growth media) and cultural practices (training, irrigation, harvesting) on size, colour, shelf life, taste and biochemical compounds are being quantified. It could be shown how light intensity and light quality effects the contents of chlorophyll, anthocyanins, ascorbic acid and nitrate in lettuce, shelf life and taste in herbs, taste and antioxidant activity in strawberry, titratable acidity and the contents of phenolics, ascorbic acid, lycopene and soluble solids in tomato. Results will be presented at the workshop. The favourable ratio between light and temperature in our region offers an opportunity to produce high quality products year-round. Norway is known as a healthy country, with little problems with pests and diseases, with an availability of renewable energy, organic growth media and organic fertiliser and with a high water quality. This gives rise to a development of organic production. Research on organic production of greenhouse vegetables started at Særheim in 2003. By now, a rational growing system for organic production of tomato is developed and a system for cucumber production is on trial. Preliminary trials show differences in the content of phenolic compounds, ascorbic acids and antioxidant activity in fruits and plants grown on organic growth media when compared to rockwool. Results will be presented at the workshop.
Sammendrag
In field experiments, clones of Norway spruce [Picea abies (L.) Karst.] showed different degrees of resistance against pathogenic fungi inoculated into the bark that correlate with differences in polyphenolic parenchyma (PP) cells of the bark. Cells of spruce callus cultures, particularly towards the callus surface, resemble PP cells and this study looks at changes in callus cells during infection and the relative resistance of cultures from clones of low (weak) or high (strong) resistance to fungal infection. Callus cultures, initiated from trees with different resistance, were co-inoculated with Ceratocystis polonica (Siem.) C. Moreau and Heterobasidion annosum (Fr.) Bref. Callus cells from strong clones resemble PP cells of bark tissue from strong clones, having more polyphenolic bodies, while callus cells from weak clones are more similar to PP cells from those clones, which have less extensive phenolic bodies. Callus cultures from trees with weak resistance were more quickly overgrown by both species of pathogenic fungi than cultures from trees with strong resistance. Callus cells of infected cultures showed changes similar to activated PP cells of bark, including enhanced accumulation of polyphenolics. Phenolic bodies were more numerous and more extensive (larger and denser) in callus cells of strong versus weak clones under all conditions. Thus, callus cells may perform similar functions in defense as PP cells in the bark. Callus from trees of varying resistance seem to reflect the relative resistance of the trees from which they are derived, and this study indicates that some mechanisms of resistance can be studied using callus from trees of different resistance.
Forfattere
Marit Almvik Ole Martin Eklo Randi Bolli Marianne Stenrød Christophe Moni Jens Kværner Tore Sveistrup Espen HauglandSammendrag
Glyfosat er det mest brukte ugrasmiddelet i Norge. I 2003 ble det omsatt over 200 tonn glyfosat her til lands og bruken er økende. Glyfosat brukes hovedsakelig mot løvtrær i skogbruket og mot kveke i kornåkeren etter innhøsting. Tradisjonelt har glyfosat blitt regnet som lite miljøskadelig sammenlignet med andre sprøytemidler, fordi det brytes raskt ned og fordi det binder seg hardt til jordpartiklene. En har hatt den oppfatning at glyfosat ikke havner i vassdragene. I takt med utviklingen av bedre analysemetoder, har glyfosat de senere årene blitt påvist i grunnvannet i flere europeiske land (Tyskland, Wales, Spania, Hellas og Danmark). Danmark henter 99% av drikkevannet sitt fra grunnvann og har nå innført forbud mot sprøyting med glyfosat på leirjord i soner nær vassdrag og risikoutsatte områder. I Norge bruker vi nesten bare overflatevann som drikkevann. Statens næringsmiddeltilsyn initierte i 1997 en undersøkelse av overflatevann som benyttes til drikkevann i Norge. Lave konsentrasjoner av glyfosat og AMPA ble da påvist i 6 drikkevannskilder (Fonahn 2002). Glyfosat er altså mer mobilt enn man hittil har trodd. I prosjektet "Plantevernmidler i miljøet - Strategisk instituttprogram for redusert miljøbelastning ved bruk av plantevernmidler" har vi undersøkt hvordan klimaet påvirker nedbrytning og transport av glyfosat her til lands. Feltforsøk med glyfosat har blitt utført på to felt: Grue i Hedmark og Målselv i Troms. Resultatene fra disse feltforsøkene hjelper oss å avdekke hvilke mekanismer som styrer skjebnen til glyfosat i norsk jord.
Forfattere
Anders Baudin Lars Eliasson Åsa Gustafsson Lina Hagström Klara Helstad Anders Qvale Nyrud Jon Bingen Sande Erlend Y. Haartveit Rune ZiethénSammendrag
Det er ikke registrert sammendrag
Forfattere
Tron Eid Kåre HobbelstadSammendrag
I Del diskuteres generelle utfordringer ved utvikling og bruk av dataprogrammer for langsiktige investerings-, avvirknings- og inntektsanalyser i skog. I tillegg til problemstillinger relatert til feil og usikkerhet i takstgrunnlaget og modellgrunnlaget, er også betydningen av samsvar mellom forutsetninger for skogbehandling i prognosen og faktisk skogbehandling gjennomført i marka tatt opp. I Del 2 er det gjort følsomhetsanalyser for å kartlegge konsekvenser av feil for middeldiameter og treantall. Tilfeldige feil for middeldiameter i intervallet 20 % til 40 % vil føre til en systematisk undervurdering av volum/ha for en skogeiendom eller et større skogområde som varierer fra 1 % til 5 % etter en framskrivning. For planlegging vil en undervurdering av potensielt avvirkningskvantum i denne størrelsesorden ha liten praktisk betydning. Ved verdsetting for større eiendommer vil en undervurdering av nåverdien som følge av for lavt beregnet avvirkningskvantum kunne utgjøre forholdsvis store kronebeløp. For enkeltbestand kan undervurderingen av volum/ha og nåverdi bli betydelig, og en bør derfor ved verdsetting av enkeltbestand registrere treantall i felt. I Del 3 er Avvirk-2000 testet ut fra intensive takster og nøyaktige oppgaver for skogbehandling over tid for en skogeiendom. Forskjeller i potensiell avvirkning for perioden 2001-2010 basert eksempelvis på 2000-data og 1970-data på 3,6 %, og tilsvarende forskjeller mellom i stående volum på 2,6 % og årlig tilvekst på 5,2 % må betraktes som små, og innenfor det som må forventes i beregninger av denne typen. Datagrunnlaget er imidlertid begrenset og resultatene kan derfor ikke betraktes som en endelig "validering" av programmet. Del 4 gir en kort beskrivelse av Avvirk-2000 slik programmet fungerer i dag. Hovedvekten i beskrivelsen er lagt på den nye funksjonaliteten som er utviklet. Dette gjelder i første rekke framskrivninger for selektive hogster, men også endringer knyttet til livsløpstrær, tilpasninger av programmet slik at det kan gjøres treslagsvise forutsetninger for skogbehandling og nye muligheter til å beregne bruttoverdier for bestand på basis av ulike spesialsortimenter av tømmer.
Forfattere
Anne Kari Bergjord Arne Oddvar SkjelvågSammendrag
God overvintring er avgjørendel for å lykkes med dyrking av høsthvete (Triticum aestivum L.). For å kunne utføre risikoberegninger for høsthvete-dyrking i et klima i endring, og på nye lokaliteter, er en avhengig av redskaper som overvintringsmodeller som kan kvantifisere forhold mellom klimatiske faktorer og plantenes evne til å overleve vinteren. Som en del av forskningsprogrammet WINSUR, der effekter av klimaforandringer blir studert, ble det utført feltforsøk med høsthvete i to vintre på tre ulike steder. To ulike sorter med høsthvete, Bjørke og Portal, ble benyttet i forsøkene. Alle plantene stod i Sjørdal fra såing og fram til midten av november for at de skulle få like herdingsforhold. I november ble de distribuert til tre ulike steder; Stjørdal, Selbu og Oppdal. Planter ble hentet inn fra felt en gang i måneden fra november til april for test av frosttoleranse og studier av fenologisk utvikling. Jordtemperatur og snøforhold påvirket plantenes nivå av frosttoleranse gjennom høst og vinter. Fenologisk utvikling ble studert både like etter inntak av planter fra felt, og etter at plantene hadde fått vokse i tre uker ved 18 C, enten ved kort (7.5 t) eller lang (18 t) dag. Lang dag ble gitt i form av fullt lys (120 mikromol/m2/s) i 18 timer den første vinteren, og lang dags-plantene mottok dermed 2.4 ganger så mye lysenergi som kort dags-plantene. Lang dags-plantene gikk over fra vegetativ til generativ utvikling mye tidligere enn kort dags-plantene. Vinteren etter, da alle planter fikk fullt lys i kun 7.5 timer, og lang dags-plantene bare fikk dagforlengingslys (4 mikromol/m2/s) etter dette, var det ingen signifikant forskjell i utviklingshastighet mellom planter fra kort og lang dag. Plantene som ble studert like etter inntak fra felt viste ingen utvikling i fenologisk utvikling i perioden november til mars. Men utviklingen gikk raskt når snøen smeltet og temperaturen begynte å stige i mars/april. Resultatene fra disse forsøkene vil, sammen med andre resultat fra feltforsøkene, bli brukt i den videre utviklingen av en overvintringsmodell for høsthvete.