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.
2004
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No abstract has been registered
Abstract
The objective of this study was to provide empirical insight into dairy farmers goals, relative risk attitude, sources of risk and risk management responses. The study also examines whether organic dairy farming, leads to important risk sources not experienced in conventional farming and, if so, howthose extra risks are managed. The data originate from a questionnaire survey of conventional (n=373) and organic (n = 162) dairy farmers in Norway. The results show that organic farmers have somewhat different goals than conventional farmers,and that the average organic farmer is less risk averse. Institutional risk was perceived as the most important source ofrisk, independently of conventional or organic production system. Keeping cash on hand wasthe most important strategy to manage risk for all dairy farmers.
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No abstract has been registered
Abstract
Border cells from the seedling root tips were added to the conidium suspensions of two soilborne rootpathogens, Fusarium sp. and Cylindrocarpon sp. The presence of border cells in the suspension clearly stimulated germination of fungal conidia. Conidia of Fusarium sp. and Cylindrocarpon sp.started to germinate within 3 hours after inoculation.When border cells were washed off, the stimulating effect disappeared. Addition of malt extract caused similar stimulation as border cells. Germination of conidia was suppressed in Al-treated plants.
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No abstract has been registered
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Chitosan, a derivate of the natural amino polysaccharide chitin, has proven effective as a potential environmentally benign antimicrobial component. Few studies have focused on chitosan applied to wood against wood inhabiting and decaying fungi.In these screening studies several mycological experiments were performed to screen chitosan as a potential wood protecting agent. Growth studies on chitosan-amended media showed total inhibition of Poria placenta, Coriolus versicolor and Aspergillus niger using 1% w/v concentration.Chitosan with high average molecular weight (MW) was more efficient against mould and staining fungi than chitosan with low MW. Agar plate leaching tests showed only a small leaching effect using a 5% concentration on A. niger and P. placenta. Decay testing with P. placenta demonstrated efficacy using 5% and 2.5% concentrations in unleached samples. Leaching decreased the efficacy of chitosan and further investigations are needed to improve the fixation in wood.
Abstract
In this study modified linseed oils, rape oil and three waxes were screened on their efficacy as wood protecting agents. By testing all products when impregnated with high retentions in Scots Pine sapwood on water repellence qualities, additionally an accelerated weathering test, drying quality, accelerated brown rot and blue stain test, an indication is formed of the capability of these products as wood protecting treatments. All oil and wax treatments significantly improve the water repellency of untreated wood. In weathering resistance, maleinised and polymerised linseed oil showed the best results in improving untreated pine sapwood dimensional stability thus reducing crack formation and decolourization by UV-light. In accelerated brown rot and blue stain tests boiled linseed oil significantly reduced degradation and staining. In addition, maleinised linseed oil and a mixture of modified linseed- and mineral oil are very well performing in the blue stain test. Overall most promising products are the maleinised oils and boiled linseed oil. The maleinised oils have good potentials in long lasting water repellency, showed some fungal growth prevention, are colour stable in weathering tests and create a dimensional stable wood product. Boiled linseed oil is not exceptionally good as a water repellent, but the good drying qualities together with easy handling makes this oil a promising product.
Abstract
Tall oil is a by-product in pulping of resinous wood by the sulphate process. Tall oil contains a complex mixture of wood extractives. Some of these extractives act as natural protection against wood decaying fungi while other serve as nutrition for the fungi. This report describes a screening of the efficacy of four refined tall oils with different chemical composition on wood decaying fungi.Testing was performed as filter paper assay and mini-block assay. In the filter paper assay growth rates of the white rot fungus Coriolus versicolor and the brown rot fungus Poria placenta were inhibited by the tall oils. None of the oils caused total inhibition of the fungi but there was a clear pattern towards increased efficacy with increased portion of resin acids in the oils.Impregnated mini-blocks with approximately 200 kg/m3 retention of tall oil after leaching showed an evident effect against Coniophora puteana and Poria placenta compared to untreated control samples. However, using the criteria from EN 113 requiring less than 3% mass loss, tall oil failed.The results indicate that decay resistance of tall oil impregnated Scots pine sapwood to the retention level used in this study is comparable with the decay resistance of Scots pine heartwood. It was expected that the efficacy of the tall oils was related to chemical composition of the oils. This was confirmed for the filter paper assay where the efficacy increased with increasing amount of resin acids. However, this pattern was not found for the mini-block assay.The protective effect of the tall oils in wood seems therefore to be more related to their hydrophobic properties than to their fungicidal properties.
Authors
Tor J. JohansenAbstract
No abstract has been registered
Authors
Birger VenneslandAbstract
No abstract has been registered