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.
2010
Authors
Aruppillai Suthaparan Arne Stensvand Sissel Torre Maria Herrero Rolf Inge Pettersen David Gadoury Hans Ragnar GislerødAbstract
The effect of day length on production and germinability of conidia and severity of disease caused by Podosphaera pannosa, the causal agent of rose powdery mildew, was studied. Whole potted plants or detached leaves of Rosa interspecific hybrid 'Mistral' were inoculated with P. pannosa and exposed to 0, 12, 18, 20, 22, or 24 h of artificial light per day in growth chambers equipped with mercury lamps. Increasing duration of illumination from 18 to 20 to 24 h per day reduced production of conidia by 22 to 62%. Exposure to 24 h of illumination per day also strongly reduced disease severity compared with 18 h. Our results suggest that increasing day lengths from 18 h per day to 20 to 24 h may suppress the disease significantly and, thereby, reduce the need for fungicide applications against powdery mildew.
Authors
Morten Nitteberg Bruce Talbot Karl Stampfer Daniel KindernayAbstract
No abstract has been registered
Abstract
Docks are among the most important perennial weeds in grasslands throughout the world and the need for more effective control methods is especially crucial in organic forage production. To find more effective control methods, field trials over 2 years at 4 Norwegian locations, were carried out mainly as a full-factorial design, including factors expected to reduce docks significantly. (i) Date of grassland establishment: may be important for preventing/decreasing the flush of seedlings from seeds as well as shoots from root fragments.(ii) False seedbed preparation: to decrease soil seed bank. (iii) Use of nurse crop (cover crop) to increase competitiveness against Rumex seedlings. (iv) Cutting the taproot, using a rotary tiller before ploughing, or the "dock-plough" (a skimmer modified to cut roots in the entire furrow width at ca 7 cm depth): as new shoots mostly come from the neck and the upper 5 cm of the taproot. (v) Ploughing depth and skimming: to decrease shoots from root fragments. Weed development was assessed as the number of emerging Rumex seedlings and plants sprouting from root fragments. Results indicated that frequently more plants emerged from seeds than from root fragments. Neither renewing the grassland in summer, nor the use of the rotary tiller or the "dock plough" reduced the number of docks in the renewed grasslands. The use of the false seedbed and nurse crop, at some locations and years, reduced the number of docks in the renewed grasslands. Deep ploughing (24cm) reduced the number of Rumex plants from roots by 65% percent compared to shallow ploughing (16cm). Furthermore, the use of a skimmer reduced the number of docks sprouting from roots by 28%. Among the investigated factors, competitiveness, false seedbed and ploughing depth, as well as ploughing quality, seems to be the most promising factors for reducing the number of docks in renewed grassland.
Abstract
CORINE Land Cover (CLC) is a seamless European land cover vector database. The Norwegian CLC2000 was completed by the Norwegian Forest and Landscape Institute (Skog og landskap) in 2008 and was produced from existing national land cover datasets wherever available. CLC has a standardized nomenclature with 44 classes. 31 classes are represented in the Norwegian dataset. CLC is a small scale map showing built up areas, agriculture, forest and semi-natural areas, wetlands and water bodies. CLC has a minimum mapping unit of 25 ha. CLC2000 can be used for visualization of the general land cover patterns in Norway at a scale 1:250 000 or smaller. CLC2000 is representing the land cover situation close to year 20001. This report presents the Norwegian CLC2000 project and the methods and automatic generalization processes that were used in the project. CORINE Land Cover is one of four land cover maps (AR5, AR50, AR250 and CLC) published by Skog og landskap. CLC2000 was produced with support from the European Environmental Agency (EEA) who has joint ownership to the product....
Abstract
CORINE Land Cover (CLC) is a seamless European land cover vector database. The Norwegian CLC for the reference year 2006 (CLC2006) was completed by the Norwegian Forest and Landscape Institute (Skog og landskap) in 2009 and was produced according to CLC2006 technical guidelines (EEA 2007). CLC has a common nomenclature with 44 classes that is used throughout Europe. 31 of these classes are found in the Norwegian dataset. A coordinating Technical Team from the European Topic Centre on Land Use and Spatial Information (ETC-LUSI) is coordinating the mapping efforts ensuring that the classification is applied in a similar fashion in each country....
Abstract
All the Norwegian CLC2006 classes are documented through descriptive statistical “profiles” of the actual contents in each class. The CLC2006 profiles are worked through based on an overlay operation between CLC2006 and AR5 (under the timberline) and AR50 (above the timberline). Based on this dataset statistics are generated, that shows the percent distribution of AR5 and AR50 classes in each CLC2006 class. The study was carried out with funding from the Norwegian Space Centre.
Authors
Eivind Vangdal Sigrid FlatlandAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Scenarios of climate changes indicate longer and more frequent spells of mild weather during winter in northern latitudes. De-hardening in perennial grasses could increase the risk of frost kill. In this study, the resistance to de-hardening of different grass species and cultivars was examined, and whether the resistance changes during winter or between years, was tested. In Experiment 1, two cultivars of timothy (Phleum pratense L.) and perennial ryegrass (Lolium perenne L.) of contrasting winter hardiness were grown under ambient winter conditions, transferred from the field in January and April 2006 to the laboratory for 9 d with controlled de-hardening conditions of 3°C, 9°C and 15°C. The timothy cultivars were tested at 3°C, 6°C and 9°C in a similar experiment (Experiment 2) in January 2007. De-hardening, measured as decrease in frost tolerance (LT50), was less in timothy than in perennial ryegrass and increased with increasing temperatures. The northern winter-hardy cultivar Engmo of timothy de-hardened more rapidly than the less-hardy cultivar Grindstad, but had higher initial frost tolerance in both experiments, whereas there was less difference between cultivars of perennial ryegrass in Experiment 1. Cultivar Grindstad of timothy lost all hardiness in early spring at all temperatures, whereas cultivar Engmo maintained some hardiness at 3°C. Cultivar Engmo de-hardened at a lower rate in 2007 than in 2006, in spite of similar frost tolerance at the start of de-hardening treatment in both years. This indicates that the rate of de-hardening was controlled by factors additional to the initial frost tolerance and that autumn weather conditions might be important for the resistance to de-hardening.
Abstract
No abstract has been registered