Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2019
Abstract
No abstract has been registered
Authors
Daniel J. Sargent Matteo Buti Nada Surbanovski May Bente Brurberg Muath K Alsheikh Matthew Peter Kent Jahn DavikAbstract
Strawberry powdery mildew (Podosphaera aphanis Wallr.) is a pathogen which infects the leaves, fruit, stolon and flowers of the cultivated strawberry (Fragaria ×ananassa), causing major yield losses, primarily through unmarketable fruit. The primary commercial control of the disease is the application of fungicidal sprays. However, as the use of key active ingredients of commercial fungicides is becoming increasingly restricted, interest in developing novel strawberry cultivars exhibiting resistance to the pathogen is growing rapidly. In this study, a mapping population derived from a cross between two commercial strawberry cultivars (‘Sonata’ and ‘Babette’) was genotyped with single nucleotide polymorphism (SNP) markers from the Axiom iStraw90k genotyping array and phenotyped for powdery mildew susceptibility in both glasshouse and field environments. Three distinct, significant QTLs for powdery mildew resistance were identified across the two experiments. Through comparison with previous studies and scrutiny of the F. vesca genome sequence, candidate genes underlying the genetic control of this trait were identified.
Abstract
Precipitation has generally increased in Norway during the last century, and climate projections indicate a further increase. The growing season has also become longer with higher temperatures, particularly in autumn. Previous studies have shown negative effects of high temperatures and, depending upon temperature conditions, contrasting effects of waterlogging on hardening capacity of timothy. We studied effects of waterlogging on seedlings of timothy (Phleum pratense, cv. Noreng) under three pre‐acclimation temperatures: 3°C, 7°C, 12°C, and in autumn natural light in a phytotron at Holt, Tromsø (69°N). After temperature treatments, all plants were cold acclimated at 2°C for three weeks under continued waterlogging treatments. Freezing tolerance was determined by intact plants being frozen in pots at incremental temperature decreases in a programmable freezer. Waterlogging resulted in a higher probability of death after freezing, and a significantly reduced regrowth after three weeks at 18°C, 24 hrs light in a greenhouse. Increasing pre‐acclimation temperatures also had a clear negative effect on freezing tolerance, but there was no interaction between temperatures and waterlogging. The results indicate that waterlogging may have negative implications for hardening of timothy and may contribute to reduced winter survival under the projected increase in autumn temperatures and precipitation.
Authors
Valentina Picchi Roberto Lo Scalzo Elisabeth Kurze Marta Fibiani Eivind Vangdal Wilfried SchwabAbstract
The present work studied the effect of the year of harvest, the genotype and the cultivation method on the nutritional quality and the allergen content of three plum cultivars. The common quality parameters and the phytochemical content strongly varied with the year and the cultivar, while the system of cultivation had a minor influence. In particular, ascorbic acid greatly decreased in 2016 compared to 2015, while polyphenols were higher in 2016. The health-promoting compounds, and particularly phenolics, were significantly correlated with the antioxidant capacity. Finally, the allergen content was strongly dependent on the content of flavan-3-ols, suggesting that this class of phenolics is determinant in influencing the allergen content in plums. Results showed that the major factor affecting the quality and the concentration of natural metabolites of plum, in addition to the diversity among genotypes, is the year-to-year variation, whereas the system of cultivation plays a marginal role.
Authors
Cornelya Klutsch Vetle Schwensen Lindgren Simo Maduna Natalia Polikarpova Tommi Nyman Paul Eric Aspholm Kristin Forfang Per-Arne Amundsen Thrond Oddvar Haugen Hans Geir Eiken Snorre HagenAbstract
No abstract has been registered
Abstract
Increasing populations of large carnivores are leading to tension and conflicts with livestock production, a situation that potentially might escalate. In Norway the objective of the large carnivore policy is two-folded: to ensure viable carnivore populations and to secure a sustainable grazing industry. The main instrument is zonation, with carnivore management zones (CMZs) prioritized for reproduction of the large carnivore species separated from other areas prioritized for grazing livestock. The objective of this paper is to describe current knowledge about the impact of the zoning management strategy on the grazing industry. This is done by documenting status and changes in sheep production, losses of livestock to predating carnivores, and the use of grazing areas inside and outside the CMZs. CMZs offering protection for lynx, wolverine, bear and wolf cover 55% of the Norwegian mainland. 30% of the sheep and 50% of the Sami reindeer grazing areas are found inside the CMZs. Livestock (semi-domestic reindeer excluded) is using 59% of the available natural pasture areas outside the CMZs, but only 26% inside the CMZs. The lowest use of available grazing areas was found inside zones for wolves (12%) and brown bears (6%). Livestock in these zones are confined to fenced enclosures, mostly on the farm itself, or moved to pastures outside the management zone for summer grazing. Livestock losses increased in the affected regions during the period when carnivores were reestablished. Later, losses declined when CMZs were established and mitigation efforts were implemented in these zones. The bulk of sheep and reindeer killed by carnivores are now found in boundary areas within 50 km off the CMZs, where sheep are still grazing on open mountain and forest ranges. Therefore, instruments to protect livestock in areas close to the CMZs are also needed. The number of sheep declined inside the CMZs from 1999 to 2014, but increased outside the zones. The reduction in the absolute number of sheep in the CMZs is balanced by a similar increase outside, thus the total sheep production in Norway is maintained. We conclude that although of little consequence for the total food production in Norway, the economic and social impact of the large carnivore management strategy can be serious for local communities and individual farmers who are affected. There is a need for more exact carnivore population monitoring to quantify the carnivore pressure, better documentation of reindeer losses, and a clearer and stricter practicing of the zoning strategy. Increased involvement of social sciences is important in order to understand the human dimension of the carnivore conflicts.
Authors
Wiktoria Kaczmarek-Derda Marit Helgheim Jan Netland Hugh Riley Kjell Wærnhus Samson Øpstad Liv Østrem Lars Olav BrandsæterAbstract
The abundance of Juncus effusus (soft rush) and Juncus conglomeratus (compact rush) has increased in coastal grasslands in Norway over recent decades, and their spread has coincided with increased precipitation in the region. Especially in water‐saturated, peaty soils, it appears from field observations that productive grasses cannot compete effectively with such rapidly growing rush plants. In autumn–winters of 2012–2013 and 2013–2014, a four‐factor, randomised block greenhouse experiment was performed to investigate the effect of different soil moisture regimes and organic matter contents on competition between these rush species and smooth meadow‐grass (Poa pratensis). The rush species were grown in monoculture and in competition with the meadow‐grass, using the equivalent of full and half the recommended seed rate for the latter. After about three months, above‐ and below‐ground dry matter was measured. J. effusus had more vigorous growth, producing on average 23–40% greater biomass in both fractions than J. conglomeratus. The competitive ability of both rush species declined with decreasing soil moisture; at the lowest levels of soil moisture, growth reductions were up to 93% in J. conglomeratus and 74% in J. effusus. Increasing water level in peat–sand mixture decreased competivitiveness of meadow‐grass, while pure peat, when moist, completely impeded its below‐ground development. These results show that control of rush plants through management may only be achieved if basic soil limitations have been resolved.
Abstract
Diffuse phosphorus loss from agricultural fields is an important contributor to the eutrophication of waterbodies. The objective of this study was to evaluate a pilot project for the implementation of mitigation measures to reduce P losses. The pilot project is situated in southwestern Norway and, covers a 14-year period (2004–2018). It included data on the implementation of mitigation measures and water quality monitoring for six small catchments. The mitigation measures consisted of no tillage in autumn, reduced P fertilizer application, grassed buffer zones, and sedimentation ponds. Extra efforts were made to reduce diffuse P losses during the period from 2008 to 2010. The project comprised economic incentives, an information campaign, and farm visits. Data from 2004 and 2010 showed that the use of P fertilizer during this period decreased by 80% and the area of no-till in autumn increased in all six catchments and covered 100% of the area in three of the six catchments in 2010. However, with decreased economic incentives after 2010, the degree to which the mitigation measures were implemented was reversed; P-fertilization increased, and no-till in autumn decreased. No significant effects of mitigation measures on total P and suspended sediment concentrations were detected. We conclude that economic incentives are necessary for the comprehensive implementation of mitigation measures and but that it is not always possible to show the effect on water quality.
Authors
Isabella BørjaAbstract
No abstract has been registered
Abstract
Deforestation influences surface properties such as surface roughness, resulting in changes in the surface energy balance and surface temperature. Recent studies suggest that the biogeophysical effects are dominated by changing roughness, and it remains unclear whether this can be reconciled with earlier modeling studies that highlighted the importance of a reduction of evapotranspiration in the low latitudes and a reduction of net shortwave radiation at the surface in the high latitudes. To clarify this situation, we analyze the local effects of deforestation on surface energy balance and temperature in the MPI‐ESM climate model by performing three separate experiments: switching from forest to grass all surface properties, only surface albedo, and only surface roughness. We find that the locally induced changes in surface temperature are dominated by changes in surface roughness for the annual mean, the response of the diurnal amplitude, and the seasonal response to deforestation. For these three quantities, the results of the MPI‐ESM lie within the range of observation‐based data sets. Deforestation‐induced decreases in surface roughness contribute substantially to winter cooling in the boreal regions and to decreases in evapotranspiration in the tropics. By comparing the energy balance decompositions from the three experiments, the view that roughness changes dominate the biogeophysical consequences of deforestation can be reconciled with the earlier studies highlighting the relevance of evapotranspiration.