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.
2008
Forfattere
Per StålnackeSammendrag
Det er ikke registrert sammendrag
Forfattere
Abdelhameed Elameen Siri Fjellheim Arild Larsen Odd Arne Rognli Leif Sundheim Susan Msolla Esther Masumba Kiddo Mtunda Sonja KlemsdalSammendrag
Sweet potato (Ipomoea batatas L.) is the fifth most important crop in the developing countries after rice, wheat, maize and cassava. The amplified fragment length polymorphism (AFLP) method was used to study the genetic diversity and relationships of sweet potato accessions in the germplasm collection of Sokoine University of Agriculture, Morogoro and Sugarcane Research Institute, Kibaha, Tanzania. AFLP analysis of 97 sweet potato accessions using ten primer combinations gave a total of 202 clear polymorphic bands. Each one of the 97 sweet potato accessions could be distinguished based on these primer combinations. Estimates of genetic similarities were obtained by the Dice coefficient, and a final dendrogram was constructed with the un-weight pair-group method using arithmetic average. AFLP-based genetic similarity varied from 0.388 to 0.941, with a mean of 0.709. Cluster analysis using genetic similarity divided the accessions into two main groups suggesting that there are genetic relationships among the accessions. Principal Coordinate analysis confirmed the pattern of the cluster analysis. Analysis of molecular variance revealed greater variation within regions (96.19%) than among regions (3.81%). The results from the AFLP analysis revealed a relatively low genetic diversity among the germplasm accessions and the genetic distances between regions were low. A maximally diverse subset of 13 accessions capturing 97% of the molecular markers diversity was identified. We were able to detect duplicates accessions in the germplasm collection using the highly polymorphic markers obtained by AFLP, which were found to be an efficient tool to characterize the genetic diversity and relationships of sweet potato accessions in the germplasm collection in Tanzania.
Forfattere
Ståle Størdal Gudbrand Lien Sjur BaardsenSammendrag
A sample selection framework that simultaneously takes into account the two-step decision-making of forest owners (first whether or not to harvest, second the level of harvesting) is applied on representative cross-sectional data for forest properties and owners in Norway. Forest management plans, property size, forested area and income from agriculture are found to increase both the propensity to harvest and the harvesting levels. Income from engagement in other outfield-related productions and debt burden increase the propensity to harvest only, while increased age impact negatively on the harvesting decision. Wage income affects both propensities to harvest and harvesting levels negatively. The results suggest that other on-property productions may stimulate harvesting decisions, while off-property income impact harvesting decisions and levels negatively. (C) 2007 Elsevier GmbH. All rights reserved.
Forfattere
M Vaarst C Leeb C Nicholas S Roderick G Smolders M Walkenhorst J Brinkman E Ströger C Winkler C Winkler E Gratzer E Gratzer V Lund Britt I.F. Henriksen Inger Hansen M NealeSammendrag
Livestock farming is an important part of organic farming systems, and it is an explicit goal of organic farming to ensure high levels of animal health and welfare (AHW) through proactive and appropriate management of breeding, feeding, housing and species specific husbandry. A goal in organic livestock farming is to minimise the use of veterinary medicines to improve food quality and protect the environment, and to do this by improving livestock living conditions rather than using alternative medical treatments. Key values influencing organic livestock production are naturalness, harmony at all levels of production, use and recirculation of local resources and adoption of the precautionary principle. The concepts of "positive health and welfare" are incorporated in EU Regulation 2092/91 on organic production. The farmer must ensure that farm animals can perform natural behaviours and live natural lives, but at the same time he/she must intervene when necessary and at first signs of disharmony in the herd. Based on various project experiences and results and research questions from different European countries, a research project entitled `Minimising medicine use in organic dairy herds through animal health and welfare planning" was initiated in mid-2007 with the aim as indicated in the title. This paper introduces the project. The first project meeting and workshop was held in Hellevad in Denmark on the 9th-12th October 2007. A summary of the outputs from the workshop is provided here. The anticipated project activities are also outlined. The project will adopt the name ANIPLAN.
Sammendrag
Anleggsfase E16 Wøyen - Bjørum. Overvåking av vannkvalitet i Isielva i 2007
Sammendrag
Bitterrote på søtkirsebær er rapportert frå Sveits, Ungarn og Norge. Det er lite publisert kunnskap om sjukdomen på søtkirsebær. Artikkelen gjev eit oversyn over arbeid gjort i Noreg.
Sammendrag
New restrictions draw governments, industry and research towards new and environmental benign wood protective agents. These agents often come from a natural source, and are also a waste product. One of these is chitosan. Chitosan is a derivative from chitin, mainly found in the exoskeleton of crustacean. Some research has been conducted on chitosan and wood. Chitosan has earlier proven good antifungal effectiveness, but to achieve a good protection, a 5 % concentration is needed, which makes the end product quite expensive. In recent research, a way to make chitosan treated wood hydrophobic has been invented. The objective of the research presented in this paper, is to describe the effectiveness of the following compounds: Chitosan, chitosan/copper, chitosan/boron and chitosan/Scanimp (a commercial wood preservative). Results show that chitosan works well alone, but has a fixation problem. Chitosan and boron give good fixation, and reduced amounts of chitosan and together give good protection against wood destroying fungi. The fire protection agents are promising, but needs higher concentration and/or better fixation to give a sufficient protection against wood destroying fungi
Sammendrag
The inhibitory effect of methanol bark extracts from six deciduous and three coniferous European tree species were bioassayed against eight fungi from the different damage categories, brown rot, white rot, canker and blue-stain. This is the first report providing data on the antifungal activity of several Europaen tree species against fungi within these damage categories. Generally the decay fungi were more inhibited by the bark extracts than the blue-stain fungi, while the lowest inhibition was found among the cancer fungi. The main pattern found between the fungal groups in relation to the bark extracts in this study is believed to be caused by the route of ingress. Acer platanoides bark extract proved to be the most effcient bark extract tested, significantly reducing the growth rate of all tested fungi. Betula pubescens bark extract generally gave the weakest reduction in growth rate. In this study, the conifer bark extracts were in general more active against the canker and blue stain ascomycete fungi than the deciduous trees extracts.
Forfattere
Alemayehu Chala May Bente Brurberg Anne Marte TronsmoSammendrag
Sorghum anthracnose caused by Colletotrichum sublineolum is one of the most destructive diseases of sorghum around the world. Owing to the production of sorghum in a wide range of agro-ecological zones with different farming systems since earlier times, diverse sorghum land races exist in Ethiopia that may be creating favorable conditions for the presence of diverse pathogen races. It is for the time being not possible to exploit the variations in the landraces to develop sustainable and affordable disease management strategies because information on the genetic diversity of both the plant and the pathogen are little or lacking in Ethiopian condition. Therefore the current project was developed with the objectives of studying the reaction of Ethiopian adapted sorghum germplasm to anthracnose infection and investigating the morphological and genetic variations among isolates of C. sublineolum from Ethiopia. Two separate experiments are being conducted to achieve these objectives. The first experiment deals with field screening of sorghum germplasm for resistance to anthracnose. More than 100 sorghum lines were screened in 2006 and 2007 cropping seasons at Alaba and Wolayta, Southern Ethiopia. Anthracnose severity at 140 days post planting, measured as the proportion of leaves covered by the disease, ranged from 11% to more than 50% over the 2 years. Results of this experiment revealed the existence of variations in the reaction of the tested lines to natural infection by anthracnose. Some of the lines appeared to possess a good level of stable resistance while others show differential reactions across experimental locations and years. This suggests not only the potential of Ethiopian adapted sorghum germplasm in serving as sources of resistance to anthracnose but also the impact environmental conditions may have on the genotype response to the disease. Furthermore this may suggest the presence of different pathogen pathotypes in the two experimental sites. The second experiment is aimed at investigating the morphological, pathogenic and genetic variations among C. sublineolum isolates from Ethiopia. To achieve this objective more than 90 leaf samples were collected from different parts of Ethiopia and brought to Norway for laboratory analysis. Single spore isolates are being grown on culture media and the genetic variations among the isolates will be analyzed using AFLP. Besides, the isolates will be characterized morphologically. In addition, selected isolates representing different genetic and morphological groups will be inoculated to sets of differential cultivars obtained from Texas, USA in a green house. The experiment will be arranged in CRD (completely randomized design) with 3 replications, and data will be recorded on the presence or absence of anthracnose and severity of the disease will be measured at a week interval to determine the pathogenecity and aggressiveness of the isolates.
Sammendrag
The frequency with which ewe lambs lay on wooden surfaces at two levels, called ``double bunks,"" was documented by video recording at 6, 11 and 18 months of age: the number in each of 4 pens (n = 4) lying either on double bunks (DBs) or on the expanded metal floor (EMF) was recorded. At 6 months, lambs were sheared half way through the research period and DBs of two different heights (50/60 cm) and depths (60/75 cm) were tested. At other ages the lambs were sheared before testing and all DBs were the 60 cm 60 cm design. Fully fleeced lambs aged 6 months preferred to lie on EMF rather than DB (P < 0.001). After shearing, the use of EMF for resting declined (P < 0.05) and no significant preference between EMF and DB was found. The lambs tended to lie less when newly sheared (P = 0.06). At 11 months, sheared lambs used DB just as much as EMF, whereas 18 month old sheared ewe lambs tended to choose DB to lie on (P = 0.09). At 6 months, there was a tendency for more lambs to rest at ground level in the DB when headroom was higher at 60 cm (P = 0.1). No other preferences between DB designs were found. The results are discussed according to the regulations for organic sheep farming in Norway. The lambs showed little preference for resting on a DB compared to EMF, so there is insufficient evidence to recommend a two-level, wooden lying area for sheep.