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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.

2016

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Sammendrag

Satisfactory seed yield of red clover (Trifolium pratense L.) cultivars is crucial for the availability of seeds on the market. Many breeders and researchers have used seed yield components to measure, compare, and explain differences in seed yield between diploid and tetraploid red clover cultivars and populations; however, the relative importance of each component varies between studies. In 2011 and 2012, single-plant trials with several tetraploid and one diploid red clover cultivar were established at the Norwegian plant breeding station at Bjørke. The goal was to study the impact of different seed-yield components on the seed yield of tetraploid plants. Seed weight per flower head was the seed-yield component that correlated best with the seed yield plant−1 (r = 0.91 and r = 0.68 in 2011 and 2012, respectively). Path coefficient analysis has also shown that the seed weight per flower head had the highest direct impact on seed yield plant−1 (direct path coefficients were 0.867 and 0.783 in 2011 and 2012, respectively). In comparison, the direct path coefficients for calculated number of flower heads, which was previously highlighted as the most important seed-yield component, were lower and more variable (0.739 and 0.392 in 2011 and 2012, respectively). Since previously seed yield per flower head was also identified as the most important seed-yield component in dense plant canopy, this component might have the potential to select for improved seed yield of new cultivars based on single plants. However, further studies are required to confirm this conclusion.

Sammendrag

In this study we present Our initial results on the assessment of Genetic diversity among Wild Bulgarian berry accessions (Rubus idaeus L. Fragaria vesca L. Vaccinium vitis-Idaea L. Vaccinium myrtillus L.)using Random Amplified Polymophic DNA (RAPDs) markers. Leaves and fruits were collected from two Natural habitats - the Balkan Mountain and the Mountain of Orpheus - Rhodope Mountain. All asseccions were screened for their polymorphism using five RAPD primers. The phylogenetic distance calculated from RAPD data ranged from0.29 to 0.82 thus indicating that a high Level of gene diversity is present in the selected genotypes. In order to characterize further the structure and grouping of berry accessions a dendrogram deriving from UPGMA cluster analysis based on the basic similarity (GS) coefficient Matrix was designed. RADP analysis provided to be efficient for discrimination of accessions within the same species With similar morphological characters.

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The production of accurate and reliable data on copper ecotoxicology of marine algae depends on the use of trace metal clean techniques during experimentation. We reviewed the methodologies used in the literature on copper ecotoxicology of marine macro- and microalgae, specifically the use of trace metal clean procedures such as the labware used (glassware vs. plasticware), methods of cleaning the labware (acid soaking and ultrapure water rinsing), stock solution preparation (copper source and acidification), and measurement and reporting of dissolved copper concentrations. In terms of taxonomic classification, the most studied algal groups were the Phyla Ochrophyta, Bacillariophyta, Rhodophyta, and Chlorophyta. In terms of methodology, ∼50% of the articles did not specify the labware, ∼25% used glassware, and ∼25% plasticware; ∼30% of the studies specified cleaning protocols for labware to remove trace metal impurities; the copper form used to prepare the stock solutions was specified in ∼80% of studies but acidification to stabilise the dissolved copper was performed in only ∼20%; and the dissolved copper concentration was measured in only ∼40% of studies. We discuss the importance of following trace metal clean techniques for the comparison and interpretation of data obtained on copper ecotoxicology in algae.

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In this paper, we estimate the cost-effectiveness of tillage methods as a measure to reduce phosphorus loss. The study was based on real-world information on costs. Data on phosphorus loss for different soil tillage methods were modelled. The cost-effectiveness of various soil tillage methods were related to autumn ploughing. The results showed large variation in cost-effectiveness related to erosion risk. Furthermore, spring harrowing was the most cost-effective method to reduce phosphorus loss, followed by autumn harrowing and spring ploughing in spring cereals. Implementation of changed tillage methods showed lower costs for spring cereals compared to winter wheat. The differences in costs between areas were most evident for spring tillage due to differences in yields and agronomic management. Cost-effectiveness is an important criterion in selecting mitigation methods, but due to large variations in the effect of changed tillage, these should be locally adapted to the high risk areas of erosion.

Sammendrag

The two-spotted spider mite, Tetranychus urticae, is a serious pest of numerous crops worldwide. Sustainable management solutions for T. urticae include predators and entomopathogens. Neozygites floridana is a naturally occurring obligate fungal pathogen of T. urticae and can cause declines in T. urticae populations. The purpose of this study was to determine whether releasing the predatory mite Phytoseiulus persimilis into T. urticae populations has the potential to increase transmission of N. floridana and accelerate the development of an epizootic. This is the first study quantifying the effect of P. persimilis on transmission of N. floridana to T. urticae in a controlled microcosm study. Our results show that introducing P. persimilis into T. urticae, populations increased the proportion of T. urticae infected with N. floridana. By the final sampling occasion, the number of T. urticae in the treatment with both the predator and the pathogen had declined to zero in both experiments, while in the fungus-only treatment T. urticae populations still persisted. We suggest that releasing P. persimilis into crops in which N. floridana is naturally present has the potential to improve spider mite control more than through predation alone.

Sammendrag

We assessed milk production with 24 mid-lactation Norwegian Red dairy cows on a spring pasture dominated by timothy (Phleum pratense) for a period of 21 days using three pasture allocation techniques (n=8). Cows received weekly allowances at once (7 day-set-paddocking; 7SP), grazed 1/7 of 7SP allowance each day (daily-strip-grazing; 1SG), or grazed like 1SG but also had access to the previously grazed part of the paddock (daily-forward-grazing; 1FG). We hypothesized that 7SP would deteriorate sward quality and quantity over the grazing days whilst the other two treatments would provide balanced pasture quality and intake. These changes were expected to result in differences in milk yield and its components. However, changes in sward chemical composition (e.g. neutral netergent fiber, crude protein) over the grazing days in each week were not different among treatments (treatment × grazing day; P>0.05). Furthermore, no effect of treatments on milk yield and its components was observed. Nonetheless, the effects of grazing days over a week on milk yield and components were different among treatments (treatment × grazing day; P<0.05). These treatment by grazing day interaction effects, in the absence main effect of treatment, could be due to fluctuations in daily DMI among treatments over the grazing days in each week.

Sammendrag

Finding new ways to simultaneously account for monetary and non-monetary goals in ecosystem services is needed in order to establish a new modelling framework for the facilitation of trade-offs between competing stakeholder interests. The socioecological sustainability of an ecosystem service is dependent on the consent of the people in the area of the ESS. An important reason is that a given ecosystem service may have highly different value in different stakeholder cultures. In this aspect is also the understanding of disservices and hidden services. The kind and level of conflict tend to differ with location and the operational level of decision-making. It is crucial work to identify all linked subservices and organise them into a common framework for evaluation. In our research group (MULTIESS) we try to develop multi-criteria tools to assess the implications of prioritizing different interests on ecological, sociological and economic output. Similarly, changes in the human population and environment will interact and influence on the services and their values, demanding such parameters to be evaluated for the whole range of potential scenarios. We maintain that in order to make multi-criteria analyses (MCA) successful, service outputs and externalities must and can be measured in familiar terms (e.g. money, biomass) without the use of direct or stated pricing of non-commodities such as welfare, recreation or biodiversity.

Sammendrag

Artikkelen presenterer resultater fra analyser av fosforinnhold i sediment i elvekanter, samt ut­ testing av fem ulike metoder for å kvanti sere kanterosjon i to leirelver på Østlandet. Gjennom­ snittlig innhold av totalfosfor i kantsedimentet var om lag 700 mg/kg. Fosforinnholdet i kant­ sedimentet var noe lavere enn i åkerjorda, men denne forskjellen kunne forklares med en lavere andel leirfraksjoner og organisk materiale i kant­ sedimentet. Metodene som ble testet ut for å kvanti­ sere kanterosjon, omfattet gjentatte befaringer og fotografering av elvekantene, erosjonspinner, fotogrammetri (3D­fotografering), sammenlig­ ning av elveløpsform med historiske yfoto, samt kjemisk sporing av sedimentet. Konklusjonen var at ingen av de utprøvde metodene er optimale, men at erosjonspinner kombinert med fotogra­ fering under befaringer kan gi et grovt estimat av erosjonen. Av 13 lokaliteter var det re hvor det ikke ble påvist erosjon, og ni lokaliteter hvor beregnede erosjonsrater utgjorde fra 100 til mer enn 1500 kg sediment pr. lengdemeter elvebredde og år. Den mest omfattende erosjonen ble funnet ved en lokalitet hvor trær langs elvekanten var kuttet ned.