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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.

2012

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Abstract

In an attempt to find alternative products to classical fungicides, several products with low toxicity were tested against powdery mildew of roses. These products included resistance inducers (Bion, BABA, and ROS), potassium salts (Resistim, monopotassium phosphate), and seed extracts. The best results were obtained with acibenzolar-S-methyl (Bion). The utilization of Bion as prophylactic treatment, watered at a concentration 0.1–0.2 mg/ml, together with good cultural practices can be enough to effectively control powdery mildew on roses. Treatments with Resistim reduced the disease incidence, but not always significantly compared to the controls. None of the other products had effect on powdery mildew.

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Abstract

This document is the Accepted Manuscript version of a Published Work that appeared in final form in [Journal of Agricultural and Food Chemistry], copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jf302924m

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Abstract

Earlier research indicates that stallions may supress interactions of their harem members,leading to less stable hierarchies and friendship bonds in harems compared to non-stallion groups. In this paper, the effect of the presense of a stallion on the social behaviour of mares was studied by comparing six harems containing stallions to four mixed sex groups not containing stallions. Both temporary and permanent harems were studied, giving the possibility to investigate the effect of group stability on social interactions. A significant linear hierarchy was found in all non-stallion groups that were used for comparison, while the hierarchies were only found to be linear in three of the six harems containing stallions (Landaus h , p < 0.05). Aggression rate was lower (t-test, p < 0.05) and fewer friendship bonds (G-test, p < 0.0001) were found within the harems, compared to the groups without stallions. Stallions seldom intervene directly in interactions between harem members. Thus, our results give support to the hypothesis that stallions may suppress interactions of harem members, but in a more indirect way than with direct interference. In addition, our results give support for earlier findings that aggression rate may be affected by group stability. We found a higher aggression rate in the temporary harems compared to the permanent harems (Kruskal–Wallis, p < 0.05) and in the temporary non-stallion group compared to the permanent non-stallion group. The results have significance for further research on social structure of mammals, and may be applied in management of domestic animals.

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Abstract

During cold storage plums (Prunus domestica L.) are susceptible to developing internal disorders, such as jellying and internal browning. Time-resolved reflectance spectroscopy (TRS) is a promising method to detect internal disorders in fruit non-destructively. Experiments were performed with plums (‘Jubileum’) stored at 1 and 4°C for three weeks. Samples of 30 plums of uniform ripeness were measured during a 5 day shelf life period without storage or after 3 weeks of storage. In addition to TRS measurements (absorption coefficients and scattering coefficients at 670 and 780 nm) standard quality factors inlcuding colour, firmness, soluble solids content and titratable acidity were analyzed. The plums were cut in halves and the amount of internal disorders was evaluated from scale 0 (healthy) to 10 (all surface affected). The correlation between internal disorders and quality factors like firmness, soluble solids content and acidity indicated that more ripe plums were more susceptible to internal disorders. Colour parameters (L*, a* b*) showed significant and negative correlations with internal disorders. The absorption coefficients measured at 670 and 780 nm increased with the development of jellying and browning, which allowed distinguishing healthy fruit from those affected by internal disorders and the slightly browned fruit from those with medium and severe browning. Scattering coefficients were not influenced by chilling injury development

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Abstract

• Parasitism and saprotrophic wood decay are two fungal strategies fundamental for succession and nutrient cycling in forest ecosystems. An opportunity to assess the trade-off between these strategies is provided by the forest pathogen and wood decayer Heterobasidion annosum sensu lato. • We report the annotated genome sequence and transcript profiling, as well as the quantitative trait loci mapping, of one member of the species complex: H. irregulare. Quantitative trait loci critical for pathogenicity, and rich in transposable elements, orphan and secreted genes, were identified. • A wide range of cellulose-degrading enzymes are expressed during wood decay. By contrast, pathogenic interaction between H. irregulare and pine engages fewer carbohydrate-active enzymes, but involves an increase in pectinolytic enzymes, transcription modules for oxidative stress and secondary metabolite production. • Our results show a trade-off in terms of constrained carbohydrate decomposition and membrane transport capacity during interaction with living hosts. Our findings establish that saprotrophic wood decay and necrotrophic parasitism involve two distinct, yet overlapping, processes.

Abstract

During the picking season in the Norwegian plum production areas, the harvested plums are brought to cold storage in packing houses once or twice a day. Plums picked late in the afternoon may even not be cooled properly until the next day. The average time from picking until the plums are placed in a cold storage is approximately 8 hours. Previous reports have shown that delayed cooling of sweet cherries and apples reduced the fruits’ susceptibility to physiological or fungal decay. An experiment was performed in order to evaluate the impact of different delay-to-cold storage times (0, 5, 10, 15 and 25 hours) on quality and phenolic contents changes of Norwegian ‘Mallard’ plums during cold storage, transport, and retail in normal atmosphere (NA). The fruits (10 fruits in PE tray, n=3) were stored for 14 days at 1°C, followed by 3 days at 7°C and then for 4 days at 20°C. Fruit quality parameters (firmness, colour in CIE L, a*, b* colour space, weight, rot occurrence (%)) and total phenol and anthocyanin content were determined. Samples were analyzed just before cold storage and then after 14 days at 1°C, 3 days at 7°C, or 4 days at 20°C. Evaluation of results has shown that delay of cooling has a retarding effect on rot development during 20°C storage (post cold transport), weight loss and stimulates anthocyanin accumulation and colour changes to some extent. At the end of storage no effect on fruit firmness could be observed.

Abstract

The flavor of apples after storage is important to the consumers. Most often factors like decay, firmness and the contents of soluble solids and acidity are regarded as the limiting factors for storability of apples. The amount of volatile aroma compounds is less studied. Using head space analyses the amounts of 8 compounds known to be important to aroma of apples were studied during storage. Some compounds increased while others decreased during storage. Apples of three cultivars and from trees treated with foliar fertilization with nitrogen and calcium were included. The early ripening cultivar ‘Discovery’ had more aroma compounds in November and less in February. In the late ripening cultivar ‘Elstar’ the content of aroma compounds was low in November. However, the amounts were more than doubled in February. The foliar fertilization with nitrogen tended to reduce the amount of aroma compounds while the highest content was found in apples from trees treated with calcium. However, these tendencies were not statistically significant. In ‘Discovery’ the content of aroma compounds may be a limiting factor to the storability of this cultivar.