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
Authors
Paal Krokene Isabella Børja Elena Carneros Toril Drabløs Eldhuset Nina Elisabeth Nagy Daniel Volařík Roman GebauerAbstract
Drought-induced mortality is a major direct effect of climate change on tree health, but drought can also affect trees indirectly by altering their susceptibility to pathogens. Here, we report how a combination of mild or severe drought and pathogen infection affected the growth, pathogen resistance and gene expression in potted 5-year-old Norway spruce trees [Picea abies (L.) Karst.]. After 5 weeks of drought, trees were inoculated with the fungal pathogen Endoconidiophora polonica. Combined drought–pathogen stress over the next 8 weeks led to significant reductions in the growth of drought-treated trees relative to well-watered trees and more so in trees subjected to severe drought. Belowground, growth of the smallest fine roots was most affected. Aboveground, shoot diameter change was most sensitive to the combined stress, followed by shoot length growth and twig biomass. Both drought-related and some resistance-related genes were upregulated in bark samples collected after 5 weeks of drought (but before pathogen infection), and gene expression levels scaled with the intensity of drought stress. Trees subjected to severe drought were much more susceptible to pathogen infection than well-watered trees or trees subjected to mild drought. Overall, our results show that mild drought stress may increase the tree resistance to pathogen infection by upregulating resistance-related genes. Severe drought stress, on the other hand, decreased tree resistance. Because drought episodes are expected to become more frequent with climate change, combined effects of drought and pathogen stress should be studied in more detail to understand how these stressors interactively influence tree susceptibility to pests and pathogens.
Authors
Quentin Lardy Mohammad Ramin Vibeke Lind Grete H. M. Jørgensen Mats Höglind Emma Matilda Ternman Mårten HettaAbstract
This study compared animal performance and enteric methane (CH4) emissions from dairy cows in a part-time grazing (PTG) system in northern Sweden. Twenty-four Nordic Red dairy cows were allocated to one of two treatments: DAY (10 h daytime pasture access) or NIGHT (12 h night-time pasture access). The cows in each treatment received the same ad libitum partial mixed ration (PMR) indoors and ad libitum herbage allowance. Methane was recorded using two linked GreenFeedTM emissions monitoring (GEM) units, on pasture and indoors. Day or night grazing showed no statistical differences in estimated grass or PMR intake, milk production or daily enteric CH4 emissions. There was a rapid decrease in diurnal CH4 emissions (28%) when the cows were moved from indoors to pasture in both grazing treatments. Using two GEM units (indoor, outdoor) in combination improved the diurnal assessment of enteric CH4 emissions during PTG conditions in the mixed feeding system.
Authors
Mélanie Spedener Karen Marie Mathisen Marie Vestergaard Henriksen Anders Nielsen Gunnar Austrheim Barbara ZimmermannAbstract
No abstract has been registered
Authors
Mathias Amundsen Kjersti Aaby Laura Jaakola Gesine Schmidt Inger Martinussen Anne Linn HykkerudAbstract
Lingonberries (Vaccinium vitis-idaea L.) have received much positive attention due to their exotic taste and high phenolic content. These small red fruits grow across Norway, a country with large variations in abiotic and biotic growth conditions. The large variations in abiotic and biotic growth conditions have potential to influence quality and availability of lingonberries. A three-year study (2019-2021) with 64 field plots across Norway have therefore been set up, with the aim of studying the effect of climate and growth conditions on lingonberries. Here, anthocyanin content in berries from the first growth season is presented. Eight locations across Norway (58 to 69°N) with supposed high production potential of lingonberries were selected. Within each location, eight stands (250 m2) with different biotic conditions were chosen. Berries from each sector were lyophilised and extracted with 70% methanol. Phenolic compounds were analysed by HPLC-DAD-MSn, with quantification of anthocyanin at 520 nm and MS used for identification. The three major anthocyanins in Norwegian lingonberries were cyanidin-3-galactoside (69-90%), -arabinoside (6-23%) and -glucoside (2-10%). Additionally, small quantities of three other cyanidin glycosides were preliminarily identified. The total content of anthocyanins in lingonberries ranged from approximately 320 to 790 mg 100 g‑1 dw. There appears to be a variation in anthocyanin concentration linked to latitude. However, as the variation was as large within the stands of each location as they were between the locations, different growth factors would also play key parts in synthesis of anthocyanins in lingonberries. Results from analysis of berries collected in 2020 and 2021 are necessary to have the basis to draw a conclusion on how biotic and abiotic factors influence anthocyanin content of lingonberries.
Authors
Martha Irene Grøseth Linda Karlsson Håvard Steinshamn Marianne Johansen Alemayehu Kidane Egil PrestløkkenAbstract
A continuous production experiment was conducted in Norway with 48 Norwegian Red dairy cows in early- to mid-lactation, to investigate the effect of grass silage with lactic acid bacteria (LAB) or formic acid (FA) additives, on milk yield (MY) and milk protein yield (MPY). Grass wilted to 250 g dry matter (DM)/kg was inoculated with homofermentative LAB to obtain LAB silage, whilst FA silage was produced adding a FA-based additive. The two silages were fed ad libitum and supplemented with an average 10.3 kg of either high (H) or low (L) metabolizable protein (MP) concentrates, in a 2 ✗ 2 factorial arrangement of treatments. The treatments were LAB silage and L concentrate, LAB silage and H concentrate, FA silage and L concentrate and FA silage and H concentrate. The use of FA resulted in lower levels of residual water-soluble carbohydrates (WSC), and higher levels of ammonia nitrogen (NH3single bondN), compared to LAB. In situ results for FA silage showed lower rumen degradability of crude protein (CP), while gas in vitro results showed lower utilizable CP (uCP), compared to LAB silage (782 vs. 750 g/kg DM and 128 vs. 119 g/kg DM, respectively). The purine over creatinine (PDC) index did not indicate any effects on the microbial protein synthesis (MPS) from any of the treatments. The higher daily intake of FA silage (12.5 vs.13.7 kg DM for LAB and FA, respectively, P < 0.001), did not result in significant differences in daily MY (31.0 vs. 30.2 kg, P = 0.208), nor MPY (1.08 vs.1.07 kg/day, P = 0.878) for LAB and FA, respectively. Feeding H concentrate gave higher MPY (P = 0.036), higher urea in milk (P < 0.001), plasma (P < 0.001) and urine (P = 0.008) and tended to give higher MY (P = 0.063) for both silages. For amino acids (AA) in plasma, alanine was higher for FA silage than for LAB silage (P = 0.030), while histidine (P = 0.001), leucine (P = 0.015) and glutamine (P = 0.007) were higher for both silages when cows were fed H concentrate. In conclusion, the FA and LAB additives did not affect MY or MPY any differently. Feeding H concentrate resulted in higher MPY for both silages, but reduced nitrogen (N) efficiency.
Abstract
Appropriate weed control measures during the renewal phase of temporary grasslands are critical to ensure high yields during the whole grassland lifecycle. The aim of this study was to determine which integrated grassland renewal strategy can most effectively control annual weeds in the sowing year and delay perennial weed re-establishment. Four split-plot trials were established at three sites dominated by Rumex spp. along a south-north gradient in Norway. The annual and perennial weed abundance was recorded during the sowing year and two or three production years. Main plots tested seven renewal strategies: 1. Spring plowing, 2. Spring plowing+companion crop (CC), 3. Summer cut+plowing, 4. Summer glyphosate+plowing, 5. Summer glyphosate+harrowing, 6. Late spring glyphosate+plowing, 7. Fall glyphosate+spring plowing+CC. Strategies 1–4 were tested in all four trials, strategy 5 in three trials, strategy 6 in two trials and strategy 7 in one trial. Plowing was performed at 20–25 cm depth, rotary harrowing at 15 cm depth, and glyphosate was applied at 2160 g a.i. ha-1. CC was spring barley (Hordeum vulgare). Subplots tested selective herbicide spraying (yes/no) in the sowing year. Results showed that effects of renewal strategies were often site-specific and differed between the sowing year and production years. Spring renewal resulted in higher perennial weed abundance than summer renewal in two out of four trials (by 3 and 12 percentage points, over all production years), and glyphosate followed by harrowing drastically increased Rumex spp. in one out of three trials (by 18 percentage points over all production years). CCs only significantly reduced perennial weed abundance in one trial (by 8 percentage points over all production years). In comparison, the selective herbicides had a strong effect on annual and perennial weeds in the sowing year in all trials. Selective herbicides reduced the weed cover from 32% to 7% cover, and averaged over the production years and sites, the perennial weed biomass fraction was 6 percentage points lower where herbicides had been applied. We conclude that while the tested renewal strategies provided variable and site-specific perennial weed control, selective herbicides were effective at controlling Rumex spp. and other perennial dicot weeds in the first two production years.
Authors
Mounir TakritiAbstract
No abstract has been registered
Abstract
To compensate for higher production costs in winter, tomato cultivars with better taste and flavor characteristics and higher selling price are often cultivated. Tomato taste and flavor is reduced during cold storage, however the reduction is often cultivar dependent. Little is known how postharvest storage conditions affect flavor and taste quality of tomatoes cultivated in greenhouses during wintertime at high latitudes. This study was aimed to analyze how postharvest storage conditions affect composition of flavor-related volatile organic compounds (VOCs) and taste quality of tomato fruits. Tomato cultivars ‘Brioso’, ‘Flavance’, ‘Piccolo’, ‘Sweetelle’, ‘Sweeterno’ were grown in greenhouses with artificial lightning in southwestern Norway during wintertime and were collected ripe. Experimental set up was simulating shortest postharvest chain for southwestern Norway, including harvest day (18°C for one day, in darkness), packaging and transport (12°C for 3 days, in darkness), retail (18°C for 2 days, with light) and consumer storage in either a refrigerator (4°C for 4 days, in darkness) or a kitchen counter (20°C for 4 days, with light). VOC composition of tomato fruits was analyzed using HS-SPME-GC-MS. Fruit quality parameters including sugars, titratable acidity (TA), dry matter content, firmness and pigments were analyzed. Laboratory results were compared to responses from a taste panel. Firmness and TA were lower for fruits after storage at both conditions compared to fresh fruits. Relative concentrations of the most flavor-related VOCs were lowest for fruits after storage at both conditions. The reduction was higher when fruits were stored at 4°C. Fruits from cultivars ‘Sweeterno’ and ‘Piccolo’ showed the lowest difference in relative VOC concentration at 4°C. Perceived overall tomato taste generally decreased after storage. Overall, storage at 20°C is favorable for preserving flavor of most winter-produced tomato cultivars, but disadvantageous for maintaining their firmness and TA.
Abstract
No abstract has been registered
Authors
Arne Verstraeten Nicolas Bruffaerts Fabiana Cristofolini Elena Vanguelova Johan Neirynck Gerrit Genouw Bruno De Vos Peter Waldner Anne Thimonier Anita Nussbaumer Mathias Neumann Sue Benham Pasi Rautio Liisa Ukonmaanaho Päivi Merilä Antti-Jussi Lindroos Annika Saarto Jukka Reiniharju Nicholas Clarke Volkmar Timmermann Manuel Nicolas Maria Schmitt Katrin Meusburger Anna Kowalska Idalia Kasprzyk Katarzyna Kluska Łukasz Grewling Małgorzata Malkiewicz Lars Vesterdal Morten Ingerslev Miklós Manninger Donat Magyar Hugues Titeux Gunilla Pihl Karlsson Regula Gehrig Sandy Adriaenssens Agneta Ekebom Åslög Dahl Marco Ferretti Elena GottardiniAbstract
The effects of tree pollen on precipitation chemistry are not fully understood and this can lead to misinterpretations of element deposition in European forests. We investigated the relationship between forest throughfall (TF) element fluxes and the Seasonal Pollen Integral (SPIn) using linear mixed-effects modelling (LME). TF was measured in 1990–2018 during the main pollen season (MPS, arbitrary two months) in 61 managed, mostly pure, even-aged Fagus, Quercus, Pinus, and Picea stands which are part of the ICP Forests Level II network. The SPIn for the dominant tree genus was observed at 56 aerobiological monitoring stations in nearby cities. The net contribution of pollen was estimated as the TF flux in the MPS minus the fluxes in the preceding and succeeding months. In stands of Fagus and Picea, two genera that do not form large amounts of flowers every year, TF fluxes of potassium (K+), ammonium-nitrogen (NH4+-N), dissolved organic carbon (DOC), and dissolved organic nitrogen (DON) showed a positive relationship with SPIn. However- for Fagus- a negative relationship was found between TF nitrate-nitrogen (NO3−-N) fluxes and SPIn. For Quercus and Pinus, two genera producing many flowers each year, SPIn displayed limited variability and no clear association with TF element fluxes. Overall, pollen contributed on average 4.1–10.6% of the annual TF fluxes of K+ > DOC > DON > NH4+-N with the highest contribution in Quercus > Fagus > Pinus > Picea stands. Tree pollen appears to affect TF inorganic nitrogen fluxes both qualitatively and quantitatively, acting as a source of NH4+-N and a sink of NO3−-N. Pollen appears to play a more complex role in nutrient cycling than previously thought.