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.
2007
Forfattere
Tor Håkon SivertsenSammendrag
A few ideas connected to the scope of scientific work in agronomy and agro meteorology and the scope of the scientific principle is first outlined. Then the concepts of `sustainability" and `sustainable agriculture" is presented, and the content of different definitions of these concepts is discussed. General ideas of using quantitative parameters, indices, to measure sustainability is presented. Then different ways of defining indices is discussed.A concept connected to `subsistence farmimg" called `tiny orchard" is presented and discussed, and the possible use of this concept `tiny orchard" as a referenc system for measuring and definig `sustainable agriculture" is discussed. The actual life cycle of a commercial agricultural product , an apple to be consumed fresh, is outlined; and this is compared to what is happening in a `tiny orchard" with and apple on an apple tree. Some importantant cycles connected to sustainable agriculture is mentioned, the fresh water cycle and the cycles of nitrogen and phosphorous. The following idea is discussed:"The idea of changing the focus in agricultural production from maximizing the crop yield to keeping the ecolological system of the farming and the local area sound and in order". Man is an organism like other organisms. He ought to take care of his surroundings and the other species, to take care of a ttallity of biological systems on the Eatth. probaly no god or gods will take care of him if does not succed in doeng this.The content of the concepts of adaption and mitigation connected to clobal change is also finally mentioned. References and biblography: Leane, M., 2005, The quest for an Environmental Metric: gazing at weather systems, a ground-breaking scientist spawned on ecological accounting standard the Wall Street might one day embrace ( http:// www.cfo/printable/article.cfn/530007?f=options), CFO Publishing Maine, T., 2005, Towards a Metric of Sustanability ( http://www.isoconference.org.au/ papers/ Maine.pdf), CSIRO Publish Jain, R., 2005, Sustainability metrics, specific indicators and preference index (http://www.springerlink.com/media/h4d4779uuq0yynfhktb6/contributions/t/2/2/5/t22524055312t88.pdf), Clean Techn. Environ. Polocy /:71-72
Forfattere
Trygve S. Aamlid Peter LandschootSammendrag
Spent mushroom substrate (SMS) is used by the turf industry in the northeastern United States for soil improvement. When tilled into soil at high rates, some turfgrass managers claim that SMS inhibits turf seed germination. Our objectives were 1) to determine if fresh SMS inhibits turf seed germination and, if so, which species are most adversely affected; 2) to evaluate whether any inhibition caused by SMS is due to osmotic effects or toxicity of compounds in SMS extracts; 3) to determine if any negative effect of SMS on germination can be eliminated by leaching the SMS-amended soil before seeding; and 4) to assess the performance of SMS on seedling emergence in the field. Germination of nine turfgrass species was evaluated in mixtures made from fresh SMS [electrical conductivity of saturated paste extract (ECe) = 11.9 dS m-1] and a loamy sand soil. Germination inhibition due to SMS was most pronounced in the following order: Colonial bentgrass (Agrostis capillaris L.) > sheep fescue (Festuca ovina L. ssp. hirtula [Hackel ex Travis] Wilkinson) > Kentucky bluegrass (Poa pratensis L.) > hard fescue (Festuca trachyphylla [Hackel] Krajina]) > creeping bentgrass (Agrostis stolonifera L.) > Chewings fescue (Festuca rubra L. sp. commutata [Thuill.] Nyman) = strong creeping red fescue (Festuca rubra L. ssp. rubra Gaud.) > slender creeping red fescue (Festuca rubra L. sp. litoralis [Meyer] Auquier) > perennial ryegrass (Lolium perenne L.). SMS had a stronger negative effect on germination rates (GRs) than on final germination percentages (FGPs). Germination of perennial ryegrass and Kentucky bluegrass on blotter paper moisted with SMS-extracts or polyethylene glycol of equivalent osmotic potentials showed that the inhibition was primarily due to osmotic effects. In an experiment with a 50% soil / 50% SMS (v/v) mixture, Kentucky bluegrass germinated better in pots that had been watered with 133 or 167% of the evaporation rate for ten days prior to seeding than in unleached pots. Although the negative effect of SMS on seed germination was not confirmed in a field study where ECe values never exceeded 4.1 dS m-1, we conclude that incorporation of high rates of SMS represents a potential problem for turfgrass establishment.
Sammendrag
The Skjønhaug constructed wetland (CW) is a free surface water (FSW) wetland polishing chemically treated municipal wastewater in southeastern Norway and consists of three ponds as well as trickling, unsaturated filters with light weight aggregates (LWA). Fluxes of nitrous oxide (N2O) and methane (CH4) have been measured during the autumn, winter and summer from all three ponds as well as from the unsaturated filters. Physicochemical parameters of the water have been measured at the same localities. The large temporal and spatial variation of N2O fluxes was found to cover a range of -0.49 to 110 mg N2O-N m-2 day-1, while the fluxes of CH4 was found to cover a range of -1.2 to 1900 mg m-2 day-1. Thus, both emission and consumption occurred. Regarding fluxes of N2O there was a significant difference between the summer, winter and autumn, with the highest emissions occurring during the autumn. The fluxes of CH4 were, on the other hand, not significantly different with regard to seasons. Both the emission of N2O and CH4 was positively influenced by the amount of total organic carbon (TOC). The measured fluxes of N2O and CH4 are in the same range as those reported from other CWs treating wastewater. There was an approximately equal contribution to the global warming potential from N2O and CH4.
Sammendrag
Several models for prediction of infection periods for lettuce downy mildew (Bremia lactucae) are based on the assumption that spores are produced at night and released in the early morning. The divergent light conditions at Nordic latitudes might affect both sporulation and spore release. Therefore, during the period 2001 to 2005 a total of 13 field trials were established in late season lettuce fields to evaluate efficacy of fungicide applications made according to the models PlantPlus (PP) and Modell-Analys (MA) in Norway. Disease severity varied from 0 to 89.4 % in unsprayed control plots at harvest. Fungicide treatments had a significant effect compared to untreated control in all but two of the field trials with disease incidence over 1 % at harvest. Fungicide applications at 10-day intervals and according to PP and MA resulted in an average of 3, 2.5 and 3.3 applications, respectively. There were no significant differences in disease severity at harvest between treatments according to 10-day interval, PP and MA for any of the field trials. Epidemics were created at two field locations that had no previous lettuce production, and a total of 59 days of spore trapping permitted the study of spore release under natural conditions. Spore production events predicted by MA were correct at 66 % of the days. However, when adjusting the criteria for spore production, 78 % of the days were correctly predicted.
Forfattere
W.G Flier L.P.N.M Kroon Arne Hermansen H.M.G van Raaij B. Speiser L. Tamm J.G. Fuchs J. Lambion Jafar Razzaghian D. Andrivon S. Wilcockson C. LeifertSammendrag
Genetic variation and pathogenicity of Phytophthora infestans isolates collected from organic potato crops of the susceptible cv. Bintje and the moderately resistant cv. Santé were assesed in France, Norway, and the United Kingdom in 2001 and in Switzerland in 2001 and 2002. Population structures differed considerably between the four P. infestans populations. Those from France, Switzerland and the UK were mainly clonal populations showing restricted levels of genetic diversity, whilst those from Norway were mixed A1 and A2 mating type populations with high levels of genetic diversity, suggesting periodical sexual reproduction. Isolates collected from cv. Bintje were on average more aggressive than or comparable to isolates from cv. Santé. Race complexity varied considerably between the regional P. infestans populations with isolates from France and Switzerland showing the highest number of virulence factors. In all pathogen samples but the French, isolates collected from cv. Santé were more complex than isolates collected from cv. Bintje. No directional selection towards increased aggressiveness towards the more resistant cultivar Santé was observed. This suggests that there is no shift towards increased level of pathogenicity in P. infestans populations following the large-scale introduction of more resistant potato varieties in organic production systems in Europe.
Sammendrag
Poinsettia (Euphorbia pulcherrima Willd. Ex Klotzsch), is a contemporary symbol of Christmas in most parts of the world. Today, Europe and North America represent the largest volume of production and sales, but demand is growing quickly in the other regions as poinsettia becomes more popular each year. In Norway, poinsettia is one of the most important pot plants, with a yearly production close to 6 million plants. Its ornamental value and innovation potential have laid the foundation for extensive research in Norway and elsewhere. Two viruses i.e. poinsettia mosaic virus (PnMV) and poinsettia cryptic virus (PnCV) can cause diseases in modern poinsettia cultivars. PnMV gives visible symptoms in poinsettia during parts of the growing season. Growers show great interest in the potential benefits of growing PnMV-free poinsettias. Traditionally, PnMV-free poinsettia plants were obtained by in vitro culture of apical meristems. However, this is a time-consuming method and the regenerated new PnMV-free poinsettia has sometimes lost the branching characteristic which is important for poinsettia. We have therefore developed an Agrobacterium-mediated transformation approach for poinsettia. Using this method, we have produced transgenic poinsettia with improved resistance against PnMV by expressing three hairpin (hp) RNA gene constructs which targeted various regions of the virus genome. Molecular analyses have confirmed the stable integration of transgenes into the poinsettia genome. This is the first report describing Agrobacterium-mediated transformation of poinsettia. The PnMV resistant transgenic poinsettia lines produced are of commercial potential. The methodology developed could also facilitate the further improvement of this ornamental plant with the aims of enhancing its disease resistance, quality traits, desirable colour and ornamental value. We have also transformed N. benthemiana to reveal the relationship of different vector constructs and the RNA silencing mediated PnMV resistance. This result will imrpove our understanding of RNA silencing mediated resistance through genetic engineering.
Forfattere
Astrid Johansen Mats HøglindSammendrag
Herbage intake (HI), milk production and sward utilisation of Norwegian Red Cattle dairy cows in mid-lactation, rotationally grazing grass/white clover swards at low, medium and high allowances (HA), were examined in three experiments (I, II and III). The daily target allowances per cow were 18 and 36 kg DM in Experiment I and 12, 18, and 24 kg DM in Experiment II and III. The cows were grazing in groups of seven (Experiment II and III) to ten (I) individuals. The proportions of white clover in the swards averaged 12 %, 40 % and 46 % in Experiment I, II and III, respectively. In addition to pasture, the cows were fed concentrate mixtures in varying amounts (0-6.8 kg) with the highest amounts offered to the highest yielding cows. HI was estimated using the n-alkane technique. No effect of HA on HI was obtained in Experiment I. In Experiment II, and for II and III combined, there was a significant positive effect of HA on HI. The average increase in HI was 0.24 kg DM per extra kg DM on offer. The utilisation of the sward (measured at 3 cm above ground level) decreased from 72 % at the lowest HA to 51 % at the highest HA in Experiment II and III. HA did not affect milk yield or milk composition significantly (P>0.05).
Sammendrag
Målet med rapporten er å kunne: " Beskrivelse av bestandsforholdene for hjort med kjønns- og alderssammensetning og antallsmessige bestandsestimat før jakt 2007. " Vise scenarier på hvordan bestandene vil endre seg ved ulike avskytingsmønster framover i tid. " Komme med anbefalinger for framtidig forvaltning av hjort i Eid. Rapporten viser sammenstillinger over ulike typer materiale fra Eid kommune. For modellering av bestand, og som grunnlag for utarbeiding av scenarier, har vi brukt en deterministisk bestandsmodell og definert et utgangspunkt for antall dyr i bestanden fordelt på ulike aldersklasser og kjønn. Tallmaterialet tyder på at hjortebestanden i Eid kommune har vært i vekst fram til om lag 1998. Etter dette har bestanden trolig hatt liten endring antallsmessig. Tallmaterialet ser ut til å indikere en liten økning i andelen bukk i bestanden de senere år, og det ser også ut til at rekrutteringa til bestanden er god, men varierer noe mellom år. Ut i fra de modellforutsetningene beskrevet ovenfor med kun små endringer i bestandsstørrelse i løpet av de siste åra (endringer på 0-1 % årlig) har vi beregna at Eid har en sannsynlig bestandsstørrelse (jaktbestand) 1900 ± 200 dyr før jakt i 2007. Denne bestandsstørrelsen vil kunne være grunnlag for et årlig uttak av 425-485 ± 40 dyr i åra framover avhengig av mål og strategier som blir lagt (se nedenfor). Vi anbefaler kommunen i det videre å gjennomføre slik avskytingsstrategi framover: " Kjønnsnøytral eller liten overvekt av hanndyr dersom man har mål om nullvekst i bestanden. " Kjønnsnøytral eller liten overvekt av hodyr i uttaket dersom man har mål om reduksjon i bestanden. " Kjønnsnøytral eller liten overvekt av hanndyr dersom man har mål om en liten vekst i bestanden. Eid kommune har trolig en bestand før jakt 2007 på 1900 ± 200 dyr, og viser at Eid kommune i 2007 kan felle fra 425-485 ± 40 hjort årlig avhengig av mål for bestandsutvikling framover. Rapporten inneholder i tillegg noen anbefalinger for Eid kommune sin hjorteforvaltning framover.
Sammendrag
The effects of photoperiod (12, 13, 14, 15 or 16 h), day-temperature (12, 15, 18, 24 or 27"C) and night-temperature (6, 9 or 12 oC) and their interactions on flower and inflorescence emergence were investigated by exposing 4 week old runner planst of strawberry cvs. Korona and Elsanta during a period of 3 weeks. A daily photoperiod of 12 or 13 h resulted in the highest numbers of plants with emerged flowers. A photoperiod of 14 h or more strongly reduced this number, while no flowers emerged at a photoperiod of 16 h. Plants exposed to photoperiods of 12 or 13 h flowered earlier and had longer flower trusses. A day-temperature of 18 oC and a night temperature of 12 oC were optimal for plants to emerge flowers and resulted in shortest time to flowering. A night temperature of 6 oC strongly reduced the number of plants that emerged flowers, especially when combined with lower day-temperatures. Photoperiod and temperature had no effect on the number of inflorescences, all flowering plants produced on average one inflorescence. The number of flowers on the inflorescence increased with decreasing day temperature and when photoperiod was raised fra 12 to 15 h. In general, `Korona" was more sensitive to photoperiod and temperature than `Elsanta", and had a lower optimal day-temperature for flower emergence. Results of this experiment may be used to produce high quality plant material or to define optimal conditions when combining flower induction and fruit production.
Sammendrag
To avoid problems with seed borne diseases in organic cereal production, seed health testing should be compulsory in certification of organic seed. In general, significantly lower infection frequencies of seed borne diseases are recorded on seedlings than on seed. Thresholds for the amount of seed borne inoculum that can be accepted for organic production are therefore needed. The aim of the work presented is to compare transmission rates of Drechslera on barley and oats under organic and conventional conditions, to be able to decide if existing thresholds used to assess the need of chemical seed treatment, can be applied for acceptance of organic seed lots, or for recommendation of alternative treatments. Field experiments were carried out in 2005 in conventional and organic fields situated close to each other at each of three locations (south/east-Norway, east-Norway and mid-Norway). 10 seed lots of barley and 10 lots of oats, with a range of seed infections (barley: 0-94 % Drechslera teres, average 31.4 %; oats: 0-66 % Drechslera avenae, average 22.0 %) were planted in rows of 100 seeds with 8 replicates in each location/`growing system". Percent emergence and seedlings with primary infections were recorded at BBCH 12-13. On average in the three locations 2.5 % and 1.8 % barley seedlings were infected when grown in conventional and organic fields, respectively. In oats, 2.0 % and 0.9 % infected seedlings were recorded in conventional and organic fields, respectively. Similar experiments will be carried out in 2006 and results from this will also be presented.