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
Reidun PommerescheSammendrag
Hva kan man forvente seg når man legger om fra konvensjonell til økologiske melkeproduksjon? Endringer i produksjonen, økonomien på økologiske melkebruk etter omlegging og kunnskap om hva som motiverte bøndene til å legge om er blitt undersøkt av NILF (Norsk institutt for landbruksøkonomisk forskning). Regnskapet til 32 økologiske melkebruk fordelt over hele landet og en spørreundersøkelse blant 23 av brukerne ligger til grunn for resultatene. Den gjennomsnittlige økologiske melkebonden er 49 år, mann, gift/samboer og har landbruksutdanning. De fleste la om produksjonen gradvis og har økt det totale arealet med i gjennomsnitt 116 dekar ved å leie jord. Utfordringer bøndene møtte i starten av omlegginga: Praktisk løsning for lufting av dyra o.l Byhets og negative naboer Janteloven Mange regler å sette seg inn i Psykiske hindringer, det vil si egne holdninger Frykt for dårlige avlinger Holdninger fra Tine og kjøttsamvirket Bygningsmessige løsninger Les mer om hele saken på Agropub, og NILF sin hjemmeside hvor også hele notatet kan lastes ned.
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
Michelle Fountain Jerry Cross Gunnhild Jåstad David HallSammendrag
Three mirids of horticultural importance in the UK have been studied to ascertain the chemicals involved sexual attraction of males to females. Lygus rugulipennis, the European tarnished plant bug, is an important pest of strawberries and raspberries causing malformation of fruit. Lygocoris pabulinus, the common green capsid, is primarily of concern on blackcurrant, but increasingly damaging on raspberry shoots. Finally, Liocoris tripustulatus, the nettle capsid, causes surface scaring on peppers and aubergines. Ordinarily mirids are controlled with sprays or chlorpyrifos. However, increasing demand for zero residues fruit and the eradication of effective pesticides from IPM programmes is rendering crops more susceptable to attack from mirids. The aim of this project is to develop a long-lived, practical lure, attractive to these species, in order to monitor populations so that effective timings of spray applications can be made to control the pests in fruit crops. It has been demonstrated that adult male L. rugulipennis are attracted to traps baited with live virgin females. Volatiles produced by virgin female L. rugulipennis have been identified as, hexyl butyrate, (E)-2- hexenyl butyrate, and (E)-4-oxo-2-hexenal and elicit electroantennographic (EAG) responses from males in analyses by linked gas chromatography"electroantennography (GC-EAG). We will report results of laboratory and field experiments with blends of the three compounds released from a range of dispensing systems including microcapillary tubes and a piezoelectric dispenser. We have also investigated the effects of various host-plant volatiles on attractiveness and made improvements to trap design and laboratory bioassay procedures.
Forfattere
M Vaarst C Leeb P Nicholas S Roderick Smolders G M Walkenhorst J Brinkman S March E Stöger E Gratzer C Winckler V Lund Britt I.F. Henriksen Berit Hansen M Neale L WistanceSammendrag
Good animal health and welfare is an explicit goal of organic livestock farming, and will need continuous development and adjustment on the farms. Furthermore, the very different conditions in different regions of Europe calls for models that can be integrated into local practice and be relevant for each type of farming context. A European project with participants from seven countries have been established with the aim of developing principles for animal health and welfare planning in organic dairy farming, based on a process where knowledge about the status within a given herd will be included as background for taking decisions and planning future improvements. An important part of the planning process is communication with other farmers as well as animal health and welfare professionals (veterinarians and advisors). Other principles such as systematic evaluation of how the improvements work in the farm ensure the continuity of the planning process. This presentation gives an overview over the current animal health and welfare planning initiatives in the participating countries and lines up the principles which are being gradually implemented in partner countries in collaboration with groups of organic farmers and organisations.
Sammendrag
Over the last decades the forestry sciences have been opened for new topics and methods. In addition to traditional forestry topics they have participated in environmental and ecosystem research. So far this type of research has been perceived as “applied”. From the modelling perspective there has been a misunderstanding among the participating disciplines of the character of knowledge being applied. Here we introduce two types of models of forest utilization and discuss their possibilities and limits for forestry sciences. The first perspective of forests is the one dominating in modelling today and in forestry sciences. It has been adopted from physics. The second perspective of forests has implicitly been adopted in the past for pragmatic reasons.
Forfattere
Nina Hovden Sæther Øystein Havrevoll Odd VangenSammendrag
Possible differences in gross and net feed balance and feed efficiency between two cattle breeds were studied. The “old” Black Sided Trønderfe and Nordlandsfe (STN) breed has hardly been selected for production traits the last decades due to a small population (800) while and the modern Norwegian Red (NR) breed (230 000) has been bred according to a modern breeding programme with genetic improvements in milk, growth, health and fertility. The study was done on lactating cows in three indoor feeding periods; ten cows in each breed group, fed roughage ad-lib and an adjusted level of concentrates. Feed intake, milk yield and -quality were recorded every week, and live weight was recorded every month. The gross energy balance was defined as energy intake subtracted by energy in produced milk, while the gross energy efficiency was computed by dividing energy in produced milk by energy intake. At the net energy level it was adjusted for energy loss or release from body tissue gain or loss. The results show that in spite of the large difference in production level, there were no breed differences in energy balance, neither at the gross nor at the net level. However, the NR was significantly more efficient when comparing gross feed efficiency, but there were no breed differences in net feed efficiency.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Øystein Johnsen Igor A. Yakovlev Daniel Kwaku A. Asante Anne Eskild Nilsen Harald Kvaalen Carl Gunnar FossdalSammendrag
In forest trees, environmental conditions during the reproduction can greatly influence progeny performance. We here suggest that temperature during zygotic embryogenesis and seed maturation regulates an “epigenetic memory” in the progeny, involving differential expression of genes that may regulate bud phenology, cold acclimation and embryogenesis in Norway spruce. Conditions colder than normal advance the timing whilst temperatures above normal delay the onset of these processes. The altered performance lasts for many years. The seedlings actually remember the temperatures and photoperiod prevailing during zygotic embryogenesis and seed maturation. We show for the first time that regenerated plants, cloned through somatic embryogenesis, express a memory of the temperatures applied during embryo development whilst growing in a common greenhouse environment. The warmer the in vitro temperature applied, the later the regenerated plants formed terminal buds in the common environment the second growth season. The differences were very large, and similar in size to a provenance separation of 4 – 6 degrees of latitude. To study a molecular mechanisms of a memory from embryo development identical crosses were performed, seed were produced in different temperature regimes (cold and warm embryonic history) and seedling were grown under long day (LD = continuous light) and short day (SD = 12 h night) conditions. We have prepared two subtracted cDNA libraries, forward and revers, representing genes predominantly expressed in plants growing from seeds obtained after embryogenesis in cold environment (CE) and warm environment (WE) after short day treatment (going to bud set). Annotation reveals considerable differences in studied transcriptomes. More than 50% of contigs were unknown. So obtained subtracted libraries is a good source of candidate genes. We used quantitative RT–PCR to study the expression patterns of 34 chosen candidate genes. Just two putative genes among them with no matching in the Database and one reverse transcriptase show constitutively differential expression in progeny from CE and WE
Forfattere
Igor A. Yakovlev Daniel Kwaku A. Asante Carl Gunnar Fossdal Jouni Partanen Olavi Junttila Øystein JohnsenSammendrag
The initiation of growth and dormancy represents critical ecological and evolutionary trade-offs between survival and growth in most perennial plants and represents one of the most basic adaptations of trees to their environment. It is likely that they regulates differently: apical bud set and dormancy induction regulates by perception of short-day signal, but bud burst regulates mostly by temperature signals. We tried to dissect these processes on phenotypical and molecular levels. Seedlings for dormancy analysis were grown under long day (LD = continuous light) and short day (SD = 12 h night) conditions. We have prepared two SSH cDNA libraries, forward and reverse, representing genes predominantly expressed in plants after short day (SD) treatment (going to bud set) and continue growing at LD. Subtracted libraries had been partially sequenced for candidate genes seeking. Annotation reveals considerable differences in studied transcriptomes. More than 50% of contigs in LD library were represented by photosynthesis related genes and just nearly 6% in SD library. High differences were found in RNA synthesis and RNA processing, protein degradation, defense and transporting genes and also in transposable elements. Each library contains large number of unknown genes (mostly in SD). So obtained subtracted libraries is a good source of candidate genes, differently expressed during regulation of bud set. Bud burst initiation was studied on grafts from 15- and 30-year old Norway spruce within 3 time-points during autumn in natural (outdoor) and “forcing” (1 week, 12 h light and 20°C constant) conditions using earlier developed candidate genes (Yakovlev et al., 2007). We used quantitative RT–PCR to study the expression patterns of 58 chosen genes related for bud set and 34 genes – for bud burst. By the experiment conditions we could study only delayed genes and constitutively expressed early genes. Among the candidate genes found, the most interesting ones were the transcription factors, calcium censors, signaling, cold- and water stress related genes. The putative role of the studied genes in development regulation bud set and bud burst is discussed.