Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2011
Forfattere
Anne Falk ØgaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Ricardo HolgadoSammendrag
In 1955 the potato cyst nematode was recorded for the first time in Agder. This detection produced the initial legislation of PCN control, and was implemented based on the statutory regulation of 1916. Since 1956 PCN was given quarantine status in infested agricultural land and home gardens. Official controls of certified seed potatoes started in 1939. Each year about 3000 soil samples are analyzed for PCN to clear areas for certified seed potato production. These areas are so far free of PCN. The total acreage with seed potatoes in 2009 was 813.7 Ha. Extensive surveys started in 1955; and were carried uninterrupted until the end of the 1990ties. These surveys included producing potato agricultural land and home gardens. In 2009 a new national survey program for the principal potato districts has started, the surveys is aimed to update the PCN occurrence. The surveys will continue during the subsequently years until all major potato areas will be cover. Statutory regulations for PCN from 1956-2010 to Support to Norwegian Food Safety Authority The regulations have without doubt contributed in preventing PCN infestations in the seed potato areas, and probably also prevented further spreading of wPCN and virulent yPCN as each the find has been placed under quarantine. Permanent grass as a statutory regulation in home garden plots may have contributed to reduce the spread of wPCN to commercial fields. The regulations have most probably made possible the early reduction in use of chemical fumigants, organophosphates or carbamate nematicides. These chemicals have not been used since the early 1970s. The domestic production of seed potato has been kept free of PCN by frequent inspections and analyses for more than 50 years. The fact that farmers are not allowed to import seed potatoes adds to the level of security. New project Studies on the biology of potato cyst nematodes (Globodera spp.) under Nordic conditions for improving management and regulation in Norway. To increase the scientific basis for amending the management system for PCN, Globodera spp under Nordic conditions.
Sammendrag
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Forfattere
Kjell AndreassenSammendrag
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Sammendrag
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Sammendrag
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Forfattere
Lone Ross Gobakken Olav Albert HøibøSammendrag
Mould growth on exterior coated cladding façades is an undesirable element and will often shorten the aesthetical service life. Mould growth on painted surfaces is influenced by type and concentration of film fungicides, the paint formulation and the wood substrate itself, and wooden cladding may experience exponential fungal deterioration caused by variation in the climatic factors, often within a small limited area. The objective of this study was to gain knowledge about which factors influence surface mould growth on coated and uncoated wooden cladding in an outdoor environment, with a special attention to modified wood substrates. The data are based on evaluation of mould growth coverage on outdoors exposed wood panels consisting of different combinations of wood substrates and surface finishes. Panels were exposed on three locations; Bogesund (Sweden), Birkenes and Sørkedalen (Norway). The panels were monitored up to 4.5 years. The analysis showed that coating typology and exposure time both had highly significant influences on mould growth. Furthermore, wood substrate, temperature and relative humidity had a significant influence on mould growth, but comparatively less than coating typology and exposure time. Siberian larch heartwood, copper-organic preserved Scots pine and Scots pine heartwood performed best among the wood substrates. Heartwood as wood type was less susceptible to mould growth than a mix of sapwood and heartwood wood and pure sapwood. Acetylated Scots pine as wood substrate and Aspen as wood species had lower resistance to mould growth than the other wood substrates and wood species, respectively. The physical surface structure of a paint film also influences the mould growth. A hard model paint was significantly more susceptible than the other model paints. A soft model paint performed best, with the least mould growth coverage. Aureobasidium pullulans (deBary) Arnaud was the dominating fungal species on all the wood substrates.
Forfattere
Alhaji S. Jeng A. Bationo B. Waswa J. M. Okeyo F. Maina J. KiharaSammendrag
Det er ikke registrert sammendrag
Forfattere
Alhaji JengSammendrag
An African Green Revolution cannot succeed without a secured supply of mineral fertilizers. This is particularly true of phosphorus, one of the key essential macronutrients. In most tropical soils, P is one of the main limiting plant nutrients and its deficiency is a major constraint for better crop production. This is mainly attributable to (i) the low total P content in soil, (ii) the relative unavailability of inherent soil P for plant uptake, and lastly (iii) the relative speed at which applied soluble sources of P such as inorganic P fertilizers and manures become fixed or changed to unavailable forms. It is clear that mining P minerals and spreading P fertilizers over the landscape is not sustainable in the long run. Cultural practices which can secure P sources and which conserve P should be made use of. Some of the measures necessary to adequately address the P problem can be listed as follows: nutrient cycling through the recycling of crop residues, green manures, animal manures, domestic and industrial wastes; the integration into the cropping system of Pmobilizing plant species which show the ability to improve P uptake even from less labile P forms and store P in the aboveground biomass even in excess of their needs; and biological means making use of mycorrhiza and other soil fauna to help extract fixed P from deep soils under low pH conditions.
Forfattere
Daniele Castagneri Ken Olaf StoraunetSammendrag
A long-term increase in radial tree growth has been reported in tropical (Lloyd & Farquhar 2008), temperate (Spiecker 1996, Voelker et al. 2006), alpine (Rolland et al. 1998) and boreal forests (Hofgaard et al. 1999) over the last decades. Variations in forest growth patterns have been ascribed to different causes, such as longer growing seasons due to climate warming (Hu et al. 2010), changes in land management practices (Hunter & Shuck, 2002), nitrogen deposition (Magnani et al. 2007), and atmospheric CO2 enhancement (Voelker et al. 2006). Tree-ring analyses provide detailed information on the past growth of forests. In order to assess the effect of climate change on forest growth, non-climatic variation should be removed from treering series. The effect of endogenous (inter-tree competition) and exogenous (insects attacks, fires, storms, human influence, etc.) disturbances on tree-ring series can be detected and reduced by considering trees from different sites. Furthermore, as tree-ring width generally decreases as trees grow older and larger, age-related growth trend should be removed, to preserve climatic lowfrequency variability of chronologies. Different detrending methods used to remove non-climatic variations need to be adapted to the objectives of a particular study....