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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.

2021

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Abstract

Nursery-grown Norway spruce Picea abies seedlings are often heavily attacked by the pine weevil Hylobius abietis on clear-cuts the first years after planting. Because the seedlings are not resource-limited during the growing phase in the nursery they are expected to invest less in defence than naturally regenerated seedlings already present on the clear-cuts. The latter have had to cope with various environmental stressors that could make them invest more in defence. We tested if naturally regenerated plants have stronger chemical defences than nursery-grown plants. Nursery-grown plants were planted in-between naturally regenerated plants on fresh clear cuts, and phenolic and terpene compounds in the stem bark were measured after one growing season. To test both constitutive and inducible defences, plants were either wounded, painted with methyl jasmonate (MeJA) to induce defences, or given a combination of both treatments. Growth and pine weevil attacks of the plants were registered. Nursery-grown plants had higher total concentrations of phenolic compounds and lower concentrations of terpenes than naturally regenerated plants. These opposite responses were reflected in very different compound profiles in the two plant types. We suggest the differences between plant types to be results of differences in plant age, stress level, genetic origin or possibly a combination of these factors. Most compounds showed no response to wounding, MeJA-treatment or wounding and MeJA-treatment combined, but the terpenes 3-carene, eucalyptol, limonene and para-cymene had higher concentrations in MeJA-treated nursery-grown plants than in control plants. These compounds are known to be effective in conifer resistance against weevils and bark beetles. Overall, 27% of our 400 study plants had signs of pine weevil damage after 3 ½ months in the field. However, treatment or plant type had no significant effect on whether plants were attacked or not and this might have been a result of the relatively low overall level of attacks in this study. Further studies are needed to disentangle the importance of plant age, stress level, genetic origin and resource availability for chemical defence mechanisms of young Norway spruce plants, as strengthening the natural resistance of nursery plants may be increasingly important in a future with less pesticide use.

Abstract

Methyl jasmonate (MeJA) treatment elicits induced resistance (IR) against pests and diseases in Norway spruce (Picea abies). We recently demonstrated using mRNA-seq that this MeJA-IR is associated with both a prolonged upregulation of inducible defenses and defense priming. Gene expression can be regulated at both a transcrip-tional and post-transcriptional level by small RNAs, including microRNAs (miRNAs). Here we explore the effects of MeJA treatment and subsequent challenge by wounding on the Norway spruce miRNA transcriptome. We found clusters of prolonged down- or upregulated miRNAs as well as miRNAs whose expression was primed after MeJA treatment and subsequent wounding challenge. Differentially expressed miRNAs included miR160, miR167, miR172, miR319, and the miR482/2118 superfamily. The most prominent mRNA targets predicted to be differentially expressed by miRNA activity belonged to the nucleotide-binding site leucine-rich repeat (NBS- LRR) family. Among other predicted miRNA targets were genes regulating jasmonic acid biosynthesis. Our re-sults indicate that miRNAs have an important role in the regulation of MeJA-IR in Norway spruce.

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Abstract

Late blight caused by Phytophthora infestans is a serious, worldwide disease on potato (Solanum tuberosum). Phytophthora infestans normally reproduces in a clonal manner, but in some areas, as the Nordic Countries, sexual reproduction has become the major determinant of the population structure. To improve the late blight forecasting in Norway, the process-based Nærstad model was developed. The model includes the structure of the underlying processes in the disease development, including spore production, spore release, spore survival and infection of P. infestans. It needs hourly weather records of air temperature, precipitation, relative humidity, leaf wetness and global radiation. The model contained 19 uncertain parameters, and from a sensitivity analysis, 12 were detected as weakly sensitive to model outputs and fixed to a nominal value within their prior boundaries. The remaining seven parameters were detected as more sensitive to model outputs and were parameterized using maximum a'posteriori (MAP) estimates, calculated through Bayesian calibration. The model was developed based on literature combined with field data of daily observed number of lesions on trap plants of the Bintje cultivar (late blight susceptible) at Ås during the seasons 2006-2008 and 2010-2011. It was further tested on daily observed number of lesions on trap plants of the cultivars Bintje, Saturna (medium susceptible) and Peik (medium resistant) at Ås during the seasons 2012-2015. For all three cultivars, the Nærstad model improved with a higher model accuracy compared to the existing HOSPO-model and the Førsund rules that both have shown relatively good correlation with blight development in field evaluations in Norway. The best accuracy was found for Bintje (0.83) closely followed by Saturna (0.79), whereas a much lower accuracy was detected for Peik (0.66).

Abstract

Many greenkeepers and authorities are concerned about the environmental risks resulting from pesticide use on golf courses. We studied leaching and surface runoff of fungicides and metabolites during two winter seasons after fall application of boscalid, pyraclostrobin, prothioconazole, trifloxystrobin and fludioxonil in field lysimeters at NIBIO Landvik, Norway. The applications were made on creeping bentgrass greens (5% slope) that had been established from seed or sod (26 mm mat) on USGA‐spec. root zones amended with Sphagnum peat or garden compost, both with 0.3‐0.4% organic carbon in the root zone. The proportions of the winter precipitation recovered as surface and drainage water varied from 3 and 91% in 2016‐17 to 33 and 55% in 2017‐18 due to differences in soil freezing, rainfall intensity and snow and ice cover. Detections of fungicides and their metabolites in drainage water were mostly within the Environmental Risk Limits (ERLs) for aquatic organisms. In contrast, concentrations in surface runoff exceeded ERLs by up to 1000 times. Greens established from sod usually had higher fungicide losses in surface runoff but lower losses in drainage water than greens established from seed. Presumably because of higher microbial activity and a higher pH that made prothioconazole‐desthio more polar, fungicide and metabolite losses in drainage water were usually higher from greens containing compost that from greens containing peat. Leaching of fungicides and metabolites occurred even from frozen greens. The results are discussed in a practical context aiming for reduced environmental risks from spraying fungicides against turfgrass winter diseases.

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Abstract

Rapporten dokumenterer utvalgte eksempler på bruk av stordata (engelsk: big data) teknologi og metode i NIBIO. Det første eksemplet er knyttet til oppdatering av arealressurskartet AR5, hvor det undersøkes om stordata-tilnærming kan benyttes for å identifisere lokaliteter der kartet må oppdateres. De neste eksemplene er hentet fra fagområdet plantehelse og tar for seg mulighetene for å bruke stordata-metode for å bedre prediksjonsmodeller og gjenkjenning av for skadegjørere.

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Abstract

The demand for animal protein has increased considerably worldwide, especially in China, where large numbers of livestock and poultry are produced. Antibiotics have been widely applied to promote growth and prevent diseases. However, the overuse of antibiotics in animal feed has caused serious environmental and health risks, especially the wide spread of antimicrobial resistance (AMR), which seriously affects animal and human health, food safety, ecosystems, and the sustainable future development of animal protein production. Unfortunately, AMR has already become a worldwide challenge, so international cooperation is becoming more important for combatting it. China’s efforts and determination to restrict antibiotic usage through law enforcement and effective management are of significance. In this review, we address the pollution problems of antibiotics; in particular, the AMR in water, soil, and plants caused by livestock and poultry manure in China. The negative impact of widespread and intensive use of antibiotics in livestock production is discussed. To reduce and mitigate AMR problems, we emphasize in this review the development of antibiotic substitutes for the era of antibiotic prohibition.

Abstract

No abstract has been registered

Abstract

Due to an EU directive making integrated pest management (IPM) mandatory, European farmers are expected to reduce their use of chemical pesticides, which may potentially increase production costs and risk of harvest loss. Less pesticide use is appreciated by many consumers and may generate a higher willingness to pay (WTP). However, IPM is a wide concept and it is difficult for consumers to distinguish between products with high and low risk of pesticide residues. As a result, consumers might use other characteristics, such as country of origin, for the identification of safer products. In this study, we investigate if a higher WTP for Norwegian strawberries is associated with a belief that they contain less pesticide residues than imported berries. We use regression analysis to estimate to what extent the difference in WTP for Norwegian and imported strawberries is correlated with various perceptions about strawberries. The analyses reveal that the stronger the belief that Norwegian strawberries have less pesticide risk than imported ones, the higher the WTP for Norwegian strawberries. This means that if consumers believe domestic farmers use little pesticides, domestic products might be able to sell at considerably higher prices than imports. Hence, it may be economically beneficial for farmers to keep pesticide use at a minimum. Furthermore, we find that consumers have a higher WTP for strawberries produced with less use of pesticides, although not pesticide-free, indicating that IPM is appreciated.