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.
2016
Authors
Mallikarjuna Rao Kovi Mats Höglind Hans Martin Hanslin Jeevan KA Samy Torben Asp Odd Arne RognliAbstract
No abstract has been registered
Authors
Ari HietalaAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
The Eurasian spruce bark beetle Ips typographus is a major forest pest in Europe, capable of mass-attacking and killing mature Norway spruces over extensive areas during outbreaks. Recurring outbreaks over the last few centuries have affected Central and Northern Europe. Outbreaks tend to be periodic and are in many cases triggered by large wind-felling events. For example in Scandinavia several large outbreaks have been triggered by storm disturbances in the last 50 years. In Europe I. typographus is widespread where spruce hosts are found except for in the British Isles. Here we review the identification and biology of this insect and present information about its invasiveness and the potential of success in early detection and control of outbreaks. There are indications that a warmer climate will increase the risk for outbreaks in the northern range of spruce in Europe, where outbreaks so far have been rare. More outbreaks are also expected at the southern margin of the spruce distribution in Europe, where lower than average precipitation seems to generally favor infestations. Establishments outside Eurasia have not been found despite frequent interceptions at ports of entry. Our experiments showed that North American spruce species may be suitable hosts and we conclude that it cannot be ruled out that future establishment can result from repeated imports. The most efficient control option of storm-triggered outbreaks is removal of wind-felled trees before the new generation beetles emerge.
Authors
Bjørn ØklandAbstract
No abstract has been registered
Authors
Åshild Ergon F Volaire P Korhonen Perttu Virkajärvi G. Seddaiu Marit Jørgensen Gianni Bellocchi Liv Østrem D* Reheul Joost BaertAbstract
No abstract has been registered
Abstract
Uncoated wood is increasingly used in building façades in Northern Europe. The benefits can be both low maintenance and low environmental impact. An even, grey color of the façade is often the intention, but in several cases, an uneven pattern of light, grey and dark/black areas is the result. The effect of weathering and the influencing factors have to be considered when designing and building uncoated and coated wooden façade to avoid unwanted weathering effects. Wood weathering is commonly described to be caused by: accumulation of extractives on the surface, photo-degradation of lignin, staining by dark colored mould fungi, checking, cracking and splitting due to moisture fluctuation and erosion. This paper reviews, analyzes and exemplifies weathering as a finishing system and design option for uncoated wood. Furthermore, it also discusses and exemplifies the main influencing factors and weathering effects on coated wood in facades.
Abstract
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.
Authors
Yordanys R. González Orelvis Portal Erik Lysøe Annarella Chea Luis Rojas Nicolai Meyling Ingeborg KlingenAbstract
The aim of this study was to evaluate the effect of conventional versus organic common bean (Phaseolus vulgaris) production on natural occurrence of Beauveria spp. as entophytes in bean plant tissue, from soil and as infections in stink bugs (Hemiptera: Pentatomidae), an important pest of bean in Cuba. Twenty-four organic and conventionally managed bean fields were sampled from September 2014 to April 2015 and Beauveria spp. were isolated and DNA extracted. PCR amplification of the intergenic Bloc region was performed for the identification of Beauveria species. Eighty-seven isolates were obtained from the soil samples by using the Galleria mellonella baiting technique. Further, 45 isolates were obtained from endophytic tissues of bean plant parts and 18 isolates were acquired from stink bugs. Only Beauveria bassiana was identified by DNA sequencing in this material. B. bassiana was more prevalent in soil, plant and stink bugs sampled from organic fields (41% soil, 22% plant, 9% bugs) compared to conventional fields (17% soil, 8% plant, 2% bugs). All plant parts were colonized by B. bassiana, but a significantly higher occurrence of this fungus was found in roots (9%) compared to stems (6%), leaves (4%) and pods (2%) in organic fields. In conventional fields there was a significantly higher occurrence of B. bassiana acquired from root (4%) and stem (3%) compared to leaves (1%) and pods (1%). Mating type PCR assays revealed that each of the isolates carried single mating types, with frequencies of 146/150 (MAT1) and 4/150 (MAT2), indicating limited potential for recombination. Our findings show that B. bassiana occur naturally as endophytes in bean fields in Cuba and contribute to a better ecological understanding of B. bassiana in agriculture.
Abstract
Grassland and the associated ruminant livestock production is the backbone of Norwegian agriculture, as ruminant products contribute nearly 50% of the gross income of the agricultural sector. About 2/3 of the agricultural area is used for temporary and permanent grassland, and a large proportion (40%) of the arable land is used for producing cereals that are included in concentrate mixtures fed to ruminants. The huge variation in climatic conditions, caused by the wide range in both latitude and altitude as well as in the distance to the coast, determines the land use and choice of species and varieties used in grassland. However, the dominating ley grassland species used in in almost all parts of the country are timothy (Phleum pratense L.), meadow fescue (Festuca pratensis Huds.) and red clover (Trifolium pratense L.). The use of perennial ryegrass (Lolium perenne L.) is increasing, particularly in the southwestern parts of the country. The grassland yields and forage feed quality have remained very much the same during the last decade, while the intensity in ruminant production, e.g. milk yield per cow, has increased considerably. Factors that have contributed to grassland yield stagnation are probably the increasing proportion of rented farmland by larger farm units, the increasing price ratio between livestock products and feed concentrates and the increasing cost of producing forage relative to the price of concentrates