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.
2023
Abstract
Taper models, which describe the shape of tree stems, are central to estimating stem volume. Literature provides both taper- and volume models for the three main species in Norway, Norway spruce, Scots pine, and birch. These models, however, were mainly developed using approaches established over 50 years ago, and without consistency between taper and volume. We tested eleven equations for taper and six equations for bark thickness. The models were fitted and evaluated using a large dataset covering all forested regions in Norway. The selected models were converted into volume functions using numerical integration, providing both with- and without-bark volumes and compared to the volume functions in operational use. Taper models resulted in root mean squared error (RMSE) of 7.2, 7.9, and 9.0 mm for spruce, pine, and birch respectively. Bark thickness models resulted in RMSE of 2.5, 6.1, and 4.1 mm, for spruce, pine, and birch respectively. Validation of volume models with bark resulted in RMSE of 12.7%, 13.0%, and 19.7% for spruce, pine, and birch respectively. Additional variables, tree age, site index, elevation, and live crown proportion, were tested without resulting in any strong increase in predictive power.
Abstract
Little is known about the environmental control of growth and flower bud initiation (FBI) in commercial blackberries. We studied the processes in the cultivars ‘Lock Ness’, ’Ouachita’ and ‘Sweet Royalla’ at 12, 16 and 20 °C in a daylight phytotron under naturally decreasing autumn daylength at Ås, Norway (59°40′ N). Growth rate increased with increasing temperature but was much lower at all temperatures in the erect ‘Ouachita’ than in the trailing cultivars ‘Lock Ness’ and ‘Sweet Royalla’. In all cultivars, FBI occurred earliest at 16 °C, whereas little or no FBI took place in ‘Ouachita’ and ‘Lock Ness’ at 12 °C. Growth cessation was earliest at 16 °C where it occurred in early September in all cultivars, suggesting a critical daylength of approximately 14 h. At variance from earlier statements, FBI started in lateral buds situated several nodes below the apex and progressed in both acropetal and basipetal directions as previously reported for red raspberry. Winter chill at 0 °C enhanced flowering in spring in marginally induced plants of all cultivars except ‘Ouachita’ grown at 12 °C, which remained vegetative in spring. The results suggest that temperature is as important as daylength for FBI in biennial-fruiting blackberry, and that winter chilling may enhance flowering and yield potential in partially induced plants.
Authors
Jorunn Elisabeth Olsen Marcos Viejo Torstein Tengs Igor A. Yakovlev Hugh Cross Paal Krokene Carl Gunnar FossdalAbstract
No abstract has been registered
Abstract
This report shows results from an experiment where it was investigated whether a powder of freeze-dried microalgae (Phaeodactylum tricornutum) had a biostimulating effect on the growth and content of nutrients and antioxidants in basil (Ocimum basilicum). The effect of the microalgae powder was tested as a supplement to either mineral fertilizer or a commercial organic fertilizer. We found no significant effect on the yield of applied microalgae powder, but there was a tendency for a higher yield with added microalgae powder for the treatment with organic fertiliser. This may be due to additional nitrogen supply with the microalgae powder. With mineral fertiliser, there was the opposite tendency, highest yield without microalgae powder. The only statistically significant effect of the microalgae powder was an increase in the concentration of boron for the treatment with organic fertiliser. This was probably an effect of a significant additional supply of boron with the microalgae biomass. There was a tendency for an increased concentration of copper with the addition of microalgae powder with both mineral and organic fertiliser, although the additional copper supply with the microalgae powder was small. With organic fertiliser, there was also a tendency towards increased phosphorus and potassium concentrations with the addition of microalgae powder. This could be a biostimulating effect as the additional phosphorus and potassium supply with the microalgae powder was small, but as mentioned, the effect was not statistically significant. We found no significant differences between the treatments for total antioxidant content.
Authors
Lampros LamprinakisAbstract
No abstract has been registered
Authors
Xiande Li Zhilu Sun Giovanna Ottaviani Aalmo Fangfang Cao Divina Gracia P. Rodriguez Chen Qian Yongxun Zhang Knut ØistadAbstract
Agricultural extension services are integral to technology adoption where they play a key role in delivering relevant agricultural information and technologies to farmers. In China, agricultural extension services are provided through experimentation, demonstration, training, and consulting. In Norway, agricultural extension is focused on collecting, developing, and coordinating agricultural knowledge to farmers. This chapter focuses on why agricultural extension is needed, how it is developed, and what services agricultural extension provides to its clients. It discusses experiences from China and Norway where agricultural extension has led to or is necessary for boosting agricultural productivity, increasing food security and safety, and improving the well-being of farmers.
Authors
Gunnhild SøgaardAbstract
No abstract has been registered
Authors
Iva Franić Michelle Cleary Ayse Gülden Aday Kaya Helena Bragança Guro Brodal Thomas L. Cech Anne Chandelier Tuğba Doğmuş-Lehtijärvi René Eschen Asko Lehtijärvi Michael Ormsby Simone Prospero Katharina Schwanda Katarzyna Sikora Hanna Szmidla Venche Talgø Miłosz Tkaczyk Anna Maria Vettraino Ana Pérez-SierraAbstract
Purpose of Review Because tree seeds have been considered a low-risk pathway for the spread of plant pathogenic fungi, their international movement is not subject to strict phytosanitary regulation. However, recent studies have provided scientific evidence that the biosecurity risk of seed trade may not be as negligible as assumed. This review summarises current knowledge about seed trade activity across the world and seed-borne plant pathogenic fungi and highlights knowledge gaps that need to be filled to mitigate the risk of spreading tree pathogens via seeds. Recent Findings Several outbreaks of severe tree diseases in natural forests and plantations worldwide have been linked to fungal pathogens spread by seed trade. Indeed, recent studies based on modern sequencing technologies have shown that tree seeds harbour highly diverse fungal communities, including well-known pathogens and fungal taxa belonging to unknown species. While it has become clear that even apparently healthy seeds can carry potentially pathogenic fungi, the likelihood of seed-borne pathogens being introduced and becoming established, spreading and causing impact in the new environment is still unclear which challenges the assessment of the phytosanitary risk posed by seed trade. Summary Our analyses show that large amounts of tree seeds have been traded among countries and continents. Based on published literature, the risk of spreading pathogenic fungi via tree seed movement is high. However, the role of the taxonomically and functionally diverse fungal communities associated with seeds is still poorly understood. In particular, more research is needed to assess the likelihood of seed-borne fungi being transmitted to the seedlings and spreading and causing impact in the new environment.
Abstract
No abstract has been registered
Abstract
No abstract has been registered