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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.

2020

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Sammendrag

Paleo-environmental data show that the distribution of African rain forests was affected by Quaternary climate changes. In particular, the Dahomey Gap (DG) – a 200 km wide savanna corridor currently separating the West African and Central African rain forest blocks and containing relict rain forest fragments – was forested during the mid-Holocene and possibly during previous interglacial periods, whereas it was dominated by open vegetation (savanna) during glacial periods. Genetic signatures of past population fragmentation and demographic changes have been found in some African forest plant species using nuclear markers, but such events appear not to have been synchronous or shared across species. To better understand the colonization history of the DG by rain forest trees through seed dispersal, the plastid genomes of two widespread African forest legume trees, Anthonotha macrophylla and Distemonanthus benthamianus, were sequenced in 47 individuals for each species, providing unprecedented phylogenetic resolution of their maternal lineages (857 and 115 SNPs, respectively). Both species exhibit distinct lineages separating three regions: 1. Upper Guinea (UG, i.e. the West African forest block), 2. the area ranging from the DG to the Cameroon volcanic line (CVL), and 3. Lower Guinea (LG, the western part of the Central African forest block) where three lineages co-occur. In both species, the DG populations (including southern Nigeria west of Cross River) exhibit much lower genetic diversity than UG and LG populations, and their plastid lineages originate from the CVL, confirming the role of the CVL as an ancient forest refuge. Despite the similar phylogeographic structures displayed by A. macrophylla and D. benthamianus, molecular dating indicates very contrasting ages of lineage divergence (UG diverged from LG since c. 7 Ma and 0.7 Ma, respectively) and DG colonization (probably following the Mid Pleistocene Transition and the Last Glacial Maximum, respectively). The stability of forest refuge areas and repeated similar forest shrinking/expanding events during successive glacial periods might explain why similar phylogeographic patterns can be generated over contrasting timescales.

Sammendrag

The open landscapes produced over centuries by small-scale farming in Norwegian coastal and fjord areas are threatened by agricultural abandonment, raising public concern for maintenance of the species-rich and valuable coastal grasslands. Semi-natural grasslands, traditionally grazed in the spring and fall and mown in summer, are most affected. Two linear programming models, one for small-scale sheep and one for small-scale mixed dairy and meat farms, both described in a separate method article, were developed. In the models is studied effects on production, grazing and land utilization, of altering government financial support among leys on arable land, enclosed farm pasture, grazing animals, and altering the (regulated) prices farmers pay for concentrate feed at the farm level. Sheep grazing can be expanded by intensification through increased fertilization and purchase of concentrate feed. Raising steers instead of bulls on dairy and beef farms with a milk quota would result in more mixed grazing by both sheep and steers, which is advantageous for the landscape. Steers are currently quite rare in Norway and their numbers can be increased with more subsidies for grazing, (Grazing Support (GS)) or by increasing the Regional Environmental Support (RES), a policy instrument targeting local projects for more grazing in specific areas. The current Agriculture and Cultural Landscape (ACL) subsidy payment places a higher value on arable land compared to the more biodiverse farm pastures, resulting in weaker incentives for keeping farm pasture in production. Raising the rate for farm pasture relative to that of arable land in the ACL scheme would result in stronger incentives for keeping such farm pasture in production, and likely increase biodiversity and landscape values. Increased GS for sheep might lead to more purchase of concentrate to keep more animals through the winter and eventually needs to be counteracted with higher prices for concentrated feedstuffs.

Sammendrag

Norway spruce (Picea abies) is a widely used Christmas tree species in the Nordic countries. Postharvest needle retention is an important characteristic for Christmas trees and compared to many fir (Abies) species, Norway spruce has poor postharvest needle retention. This trait is one of the most important qualities in choice of natural versus plastic trees. In this study, current year shoots were cut from 30 Norway spruce seedlot sources, including the most widely used Norwegian Christmas tree provenances, and tested to identify genetic variation in postharvest needle retention. Current year shoots were collected from one field in November and December 2018, and from three fields in October, November and December 2019. The current year shoots were displayed indoors under controlled conditions and allowed to dry. Differences in postharvest needle retention were seen between seedlots, harvesting dates and locations. Our study indicates possibilities of selecting for improved postharvest needle retention in Norway spruce seed sources. Furthermore, postharvest needle retention should be considered as one characteristic to add in the ongoing Norway spruce Christmas tree breeding program.

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Sammendrag

Potato cyst nematodes (PCN), such as Globodera rostochiensis and Globodera pallida, are quarantine restricted pests of potato causing major yield and financial losses to farmers. G. rostochiensis was first reported from Kenya’s key potato growing area in 2015. We sought to determine the diversity, prevalence and distribution of PCN species across the country by conducting a country-wide survey between 2016 and 2018, which included a more focused, follow-up assessment in three key potato growing counties. A total of 1,348 soil samples were collected from 20 potato growing counties. Information regarding local potato farming practices, potato cultivar use, their diversity and availability was also recorded. PCN cysts were obtained from 968 samples (71.8%) in all the counties surveyed, with Nyandarua County recording the highest PCN field-incidence at 47.6%. The majority of PCN populations, 99.9%, were identified as G. rostochiensis, while G. pallida was recovered from just one field, in a mixed population with G. rostochiensis. Inconsistencies in PCR amplification efficiency was observed for G. rostochiensis using the recommended EPPO primers, compared with ITS primers AB28/TW81, indicating that this protocol cannot be entirely relied upon to effectively detect PCN. Egg density in Nyandarua County varied between 30.6 and 158.5 viable eggs/g soil, with an average egg viability of 78.9 ± 2.8% (min = 11.6%, max = 99.9%). The PCN-susceptible potato cultivar named Shangi was the most preferred and used by 65% of farmers due to its shorter dormancy and cooking time, while imported cultivars (Destiny, Jelly, Manitou, and Markies) with resistance to G. rostochiensis were used by 7.5% of farmers due to unavailability and/or limited access to seeds. Thus, most farmers preferred using their own farm-saved seeds as opposed to purchasing certified seeds. Establishing the distribution and prevalence of PCN and elucidating the local farming practices that could promote the spread of PCN is a necessary precursor to the implementation of any containment or management strategy in the country and ultimately across the region.

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En har i denne studien undersøkt potensialet for å erstatte fossilt drivstoff med elektrisk energi fra batterier og/eller hydrogenbrenselceller i traktorarbeidet på norske gårder. Dette ble gjort med utgangspunkt i seksten små og store modellgårder på Østlandet, i Trøndelag og i Rogaland. Disse var korngårder med og uten husdyr, og melkeproduksjonsbruk. Det årlige dieselforbruket i alle traktordrevne arbeidsoperasjoner ble beregnet og videre tidfestet og fordelt gjennom året. For alle brukstyper var det høye topper med mye traktorarbeid knyttet til pløying og/eller spredning av husdyrgjødsel om våren og til innhøsting og pløying om høsten...

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Sammendrag

Nordic water bodies face multiple stressors due to human activities, generating diffuse loading and climate change. The ‘green shift’ towards a bio-based economy poses new demands and increased pressure on the environment. Bioeconomy-related pressures consist primarily of more intensive land management to maximise production of biomass. These activities can add considerable nutrient and sediment loads to receiving waters, posing a threat to ecosystem services and good ecological status of surface waters. The potential threats of climate change and the ‘green shift’ highlight the need for improved understanding of catchment-scale water and element fluxes. Here, we assess possible bioeconomy-induced pressures on Nordic catchments and associated impacts on water quality. We suggest measures to protect water quality under the ‘green shift’ and propose ‘road maps’ towards sustainable catchment management. We also identify knowledge gaps and highlight the importance of long-term monitoring data and good models to evaluate changes in water quality, improve understanding of bioeconomy-related impacts, support mitigation measures and maintain ecosystem services.

Sammendrag

This is a report on the potential of NanoPro™ to reduce the rate of two commonly used fungicides for control of Microdochium patch (Microdochium nivale), the economically most important turfgrass disease in Scandinavia. The experiment was conducted from 14 Sept. 2018 to 1 May 2019 on an annual bluegrass golf green at the NIBIO Turfgrass Research Center Landvik. Use of NanoPro™ at a rate of 292 ml/ha in tank mixture with the systemic fungicide Delaro® SC 325 or/and the contact fungicide Medallion® TL produced the same level of disease control with a 30-60% reduction in fungicide dosage as with full fungicide dosage without additive. NanoPro™ was more effective with Medallion® TL than with Delaro® SC 325. We conclude that NanoPro™ may have a big potential in Scandinavia and other countries where authorities require reduced fungicide use. The experiment should be repeated one more year before giving final recommendations.