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.
2022
Authors
Mekjell Meland Milica Fotiric-Aksic T Tosti U Gasic Nikola Horvacki Radoslav Cerovic Z TesicAbstract
No abstract has been registered
Abstract
Denne rapporten omhandlar resultat frå kartlegging av næringsstatusen i norske eplehagar. Jord,- blad og fruktprøvar vart samla inn frå ulike eplehagar på Aust- og Vestlandet med variasjon i jordart, innhald og type organisk materiale i åra 2018-2020. Føremålet var å studera samanhengane mellom plantefysiologiske sider i epletreet relatert til jorda, treveksten, avling og fruktkvalitet. Resultat frå det treårige studiet om verknaden av gjødselpraksisar på opptak av mineral i blada, avling og fruktkvallitet hjå ulike eplesortar frå fire regionar er samla i denne rapporten. This report is summarizing results from a survey analyzing the nutrient levels in fruit trees and soil in four fruit growing regions in Norway during the seasons 2018-2020. The aim was to study the relationship between main plant physiological principles in the tree, related to the soil, tree growth, yield, fruit quality, and fruit storage. The results of a three-year study of apple tree fertilization practices on orchard soil fertility, leaf mineral composition, apple tree yields and fruit quality of several apple cultivars in four main apple producing regions in Norway are compiled in this report.
Abstract
This study evaluated the effective pollination period (EPP) in four European plum (Prunus domestica L.) cultivars (‘Mallard’, ‘Edda’, ‘Jubileum’, and ‘Reeves’) during two years (2018–2019) under the environmental conditions in western Norway. The pollination of plum cultivars was carried out one, three, five, seven, and nine days after anthesis (DAA) with a pollen mix of two compatible cultivars (‘Victoria’ and ‘Opal’). Initial, middle-season, and final fruit set was recorded after one month and two months after pollination and just before the harvest, respectively. On average from both years cultivar ‘Jubileum’ had the highest fruit set when pollinated one, three, five, seven, and nine DAA (33.23%, 30.83%, 8.47%, 3.08%, and 1.15%, respectively), which was more than two folds higher fruit set than in the other studied cultivars. Cultivar ‘Jubileum’ showed significantly reduced fruit set between pollination on five and nine DAA, while cultivars ‘Mallard’, ‘Edda’, and ‘Reeves’ had markedly reduced fruit set if pollinated three to five DAA, implying that the EPP in ‘Jubileum’ was five days while in the rest it was three days. Variation of weather conditions during the flowering period in both years did not have a major effect on the receptivity of stigmas in the studied plum cultivars, which means that the existing differences in the length of EPP is maternal-genotype dependent.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Compatibility and synchrony between specialized tissues of the pistil, female gametophytes and male gametophytes, are necessary for successful pollination, fertilization, and fruit set in angiosperms. The aim of the present work was to study the development and viability of embryo sacs, as well as fertilization success, in relation to the fruit set of the cultivars ‘Mallard’, ‘Edda’, ‘Jubileum’, and ‘Reeves’, under specific Norwegian climatic conditions. Emasculated, unpollinated, and open-pollinated flowers were collected at the beginning of flowering, and on the 3rd, 6th, 9th, and 12th days after flowering, from all four plum cultivars over two years (2018/2019). Ovaries were dehydrated, embedded in paraffin wax, sectioned, stained, and observed under a light microscope. Results showed the existence of synchronization between successive phases in the development of the embryo sac and individual phases of flowering. All plum cultivars had higher percentages of viable embryo sacs, fertilized embryo sacs, and fruit set in 2018 than in 2019. These differences may be related to the very low temperatures during the post-full-flowering period in 2019, and to the low adaptation of some studied cultivars to unfavorable conditions. In our study, the cultivar ‘Jubileum’ showed the highest percentage of viable embryo sacs, fertilized embryo sacs, and fruit set compared to other cultivars, i.e., the best low-temperature adaptation.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
The worldwide decline in bees and other pollinating insects is a threat to biodiversity and food security, and urgent action must be taken to stop and then reverse this decline. An established cause of the insect decline is the use of harmful pesticides in agriculture. This case study focuses on the use of pesticides in Norwegian apple production and considers who among farmers, consumers and public authorities is most responsible for protecting bees against harmful pesticides. The extent to which these three different groups consider themselves responsible and the degree to which they are trusted by each of the other groups are also studied. This empirical study involves both qualitative interviews with Norwegian apple farmers, consumers and public authorities and survey data from consumers and farmers. The results show that consumers consider public authorities and farmers equally responsible for protecting bees, while farmers are inclined to consider themselves more responsible. Farmers, consumers and public authorities do not consider consumers significantly responsible for protecting bees, and consumers have a high level of trust in both farmers and public authorities regarding this matter. This study also finds that a low level of consumer trust in farmers or public authorities increases consumers’ propensity to purchase organic food, suggesting that those who do not trust that enough action is adopted to protect the environment take on more individual responsibility. This paper adds to the existing literature concerning the allocation of responsibility for environmental outcomes, with empirical evidence focusing specifically on pesticides and bees.
Authors
Ali Hosseini Hans-Christian Teien Till Seehusen Merete Myromslien Marit Nandrup Pettersen Justin Brown Brit Salbu Deborah Helen OughtonAbstract
A series of 131I tracer experiments have been conducted at two research stations in Norway, one coastal and one inland to study radioiodine transfer and dynamics in boreal, agricultural ecosystems. The hypothesis tested was that site specific and climatological factors, along with growth stage, would influence foliar uptake of 131I by grass and its subsequent loss. Results showed that the interception fraction varied widely, ranging from 0.007 to 0.83 over all experiments, and showing a strong positive correlation with biomass and stage of growth. The experimental results were compared to various models currently used to predict interception fractions and weathering loss. Results provided by interception models varied in the range of 0.5–2 times of the observed values. Regarding weathering loss, it was demonstrated that double exponential models provided a better fit with the experimental results than single exponential models. Normalising the data activity per unit area to remove bio-dilution effects, and assuming a constant single loss rate gave weathering half-times of 22.8 ± 38.3 and 10.2 ± 8.2 days for the inland and coastal site, respectively. Whilst stable iodine concentrations in grass and soil were significantly higher (by approximately a factor of 5 and 7 times for grass and soil respectively) at the coastal compared to the inland site, it was not possible to deconvolute the influence of this factor on the temporal behaviour of 131I. Nonetheless, stable iodine data allowed us to establish an upper bound on the soil to plant transfer of radioiodine via root uptake and to establish that the pathway was of minor importance in defining 131I activity concentrations in grass compared to direct contamination via interception. Climatological factors (precipitation, wind-speed and temperature) appeared to affect the dynamics of 131I in the system, however the decomposition of these collective influences into specific contributions from each factor remains unresolved and requires further study. The newly acquired data on the interception and weathering of radioiodine in boreal, agricultural ecosystems and the reparametrized models developed from this, substantially improve the toolbox available for Norwegian emergency preparedness in the event of a nuclear accident.