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
Sammendrag
Målet med rapporten er å kunne: " Beskrivelse av bestandsforholdene for hjort med kjønns- og alderssammensetning og bestandsestimat før jakt 2008. " Beskrive ulike scenarier om hvordan bestanden vil endre seg ved ulike avskytingsmønster framover i tid. " Komme med anbefalinger for framtidig forvaltning av hjort i Gloppen. Rapporten viser sammenstillinger over ulike typer materiale fra Gloppen kommune. For modellering av bestand, og som grunnlag for utarbeiding av scenarier, har vi brukt en deterministisk bestandsmodell og definert et utgangspunkt for antall dyr i bestanden fordelt på ulike aldersklasser og kjønn. Gloppen kommune hadde sannsynligvis hatt en på en stor økning i bestanden i løpet av 1990-tallet og fram til om lag 1998. Da fulgte en del åra med en mer eller mindre utflating av uttaket og sannsynligvis også bestanden. Ut fra avskytningen og overvåkningsdata ser det ut til at bestandens igjen har økt noe de siste par åra. Overvåkningsdataene (innmarkstellingene og sett hjort) tyder på en økning i andelen bukk i bestanden de senere åra. Hvis man sammenholder denne utviklingen (økt andel bukk) med at den faktiske avskytningen, som har en overvekt av hanndyr i uttaket, så tyder dette også på en økning i bestandsstørrelsen. Både sett hjort og innmarkstellingene tyder på en variasjon i rekruttering til bestanden mellom åra, men usikkerheten i disse talla er foreløpig relativt stor. Ut fra de forutsetningene vi har satt i bestandsmodellen sammenholdt med avskytningstall og overvåkningsdata har Gloppen kommune en sannsynlig (jakt) bestand før jakt i 2008 på 3000 ± 300 dyr. Denne bestanden kan gi et bærekraftig uttak i 2008 på 630-735 ± 60 hjort avhengig av hvilke mål man har for bestandsutviklingen framover. Rapporten inneholder i tillegg noen anbefalinger for Gloppen kommune sin hjorteforvaltning for åra som kjem.
Forfattere
Arnfinn Nes Bjørn Hageberg Jørn Haslestad Rune HagelundSammendrag
The cultivar `Veten" has for many years been nearly the only red raspberry cultivar grown in Norway. The cultivation methods have therefore been developed and adapted to this cultivar. In later years the cultivar `Glen Ample" has become the most used cultivar. This cultivar also grows vigorously, but has a different growth habit from `Veten". The primocanes grow taller and the laterals are longer so the rows are mostly very high and dense. An experiment was established to find the optimal cane height and density for growing high quality raspberry of this cultivar. The experiment was established in a four-year-old field with `Glen Ample" in the spring of 2004. The canes were fixed to two wires that were 90 cm apart and every second cane was fixed to each wire. The canes were topped two buds above the wire, and the height of the wires was either 140 cm or 160 cm. Different cane densities were established by leaving 6, 8 or 10 canes per meter row at pruning early in the spring. There was no interaction between the experimental factors neither on berry size nor yield. The 20 cm difference in cane height did neither affect yield nor berry size. Cane density showed significant effects on yield. Crop per cane and per hectar increased with cane density. Berry size was not affected. The berries were, however, 20 per cent bigger the second year when the field was under polyethylene tunnels.
Forfattere
Berit Nordskog David M. Gadoury May Bente Brurberg Tor Håkon Sivertsen Roy Kennedy Arne HermansenSammendrag
Downy mildews represent some of the most important plant diseases in the production of several field vegetable crops in Norway. Disease outbreaks are difficult to predict since severity of the diseases and the first appearance of the pathogens can differ substantially between seasons. As part of an ongoing project, the initial sources of inoculum for downy mildews of onion (Peronospora destructor), lettuce (Bremia lactucae) and cucumber (Pseudoperonospora cubensis) is investigated to ensure the use of appropriate control measures for these diseases in Norway. Necrotic leaf tissue from infected plants has been examined for the presence of oospores. Oospores have so far been found profusely in lettuce and sparsely in onion, but not in cucumber. Other aspects that are surveyed are the distribution of spores in air. Spore traps are used to identify both the initial appearance of inoculum, and the presence and amount of spores over a field. To determine spore quantities, real-time PCR has been applied to analyze daily spore catch. These results were compared to data from parallel spore traps where hourly numbers of spores are enumerated by use of microscope. An attempt to backtrack an early infection of P. cubensis was made by producing trajectories to show where possible sources of infection may be located in the case of long distance distribution of spores by air. This work will be continued in 2008 and 2009, and the results will be used for better forecasting of downy mildew pathogens in Norway.
Sammendrag
Colletotrichum acutatum is the causal agent of anthracnose/bitter rot in cherry and apple in Norway. It is the most important fruit decay in sour cherry in the country and may give severe losses also in sweet cherry and apple. Single spore isolates frequently develops the ascigerous stage of the fungus (Glomerella acutata) in culture, but it has not yet been detected on apple or cherry plant material. We thus anticipate that the predominant inoculum source is conidia (formed in acervuli). The fungus overwinters in old infected fruits and fruit stalks, in bud shells and in wood of cherry and apple. Infected flowers and leaves may serve as additional inoculum for fruit infections during the growing season. If still attached to the tree, fruits and fruit stalks of sour cherry infected the previous year may produce inoculum of C. acutatum throughout the entire following season. Up to 80% of the fruit spurs on sweet cherry may have buds infected with C. acutatum in spring. Apple buds may also contain the fungus. More than 90% of the sweet cherry leaves may contain C. acutatum around harvest in heavily infected orchards. The entire leaf surface may be infected, but visible infections never appear. We frequently also find such asymptomatic leaf infections in apples. Most of the inoculum seems to be present on the fruit trees themselves. However, initial inoculum in newly planted, disease free plantings may come from older fruit trees, ornamentals and weeds in or in close vicinity to the orchards.
Forfattere
M. Bagher Farmani Nils-Otto Kitterød Henk KeersSammendrag
A method is presented to estimate flow parameters and geological structure in the vadose zone by combining time-lapse Ground Penetrating Radar (GPR) traveltime tomography and inverse flow modeling. The traveltime tomography is used to determine the spatial electromagnetic velocity distribution in the vadose zone. These time-lapse velocity images are converted to time-lapse volumetric soil water content images using petrophysical relationships. Subsequently, the water content images are used as constraints in the flow inversion. The influence of the tomographic artifacts on the flow inversion is minimized by assigning weights that are proportional to the ray coverage. Our flow inversion algorithm estimates the flow parameters and calibrates the geological structure. The geological structure is defined using a set of control points, the positions of which can be modified during the inversion. After the inversion, the final geological and flow model are used to compute GPR traveltimes to check the consistency between these computed traveltimes and the observed traveltimes.The method is first tested on two synthetic models (a steady state and a transient flow models). Subsequently, the method is applied to characterize a real vadose zone at Oslo Airport Gardermoen, Norway, during the snowmelt in 2005. The flow inversion method is applied to locate and quantify the main geological layers at the site. In particular the inversion method identifies and estimates the location and properties of thin dipping layers with relatively lowpermeability. The flow model is cross validated using an independent infiltration event.
Forfattere
Berit Nordskog David M. Gadoury May Bente Brurberg Tor Håkon Sivertsen Roy Kennedy Arne HermansenSammendrag
Downy mildews represent some of the most important plant diseases in the production of several field vegetable crops in Norway. Disease outbreaks are difficult to predict since severity of the diseases and the first appearance of the pathogens can differ substantially between seasons. As part of an ongoing project, the initial sources of inoculum for downy mildews of onion (Peronospora destructor), lettuce (Bremia lactucae) and cucumber (Pseudoperonospora cubensis) is investigated to ensure the use of appropriate control measures for these diseases in Norway. Necrotic leaf tissue from infected plants has been examined for the presence of oospores. Oospores have so far been found profusely in lettuce and sparsely in onion, but not in cucumber. Other aspects that are surveyed are the distribution of spores in air. Spore traps are used to identify both the initial appearance of inoculum, and the presence and amount of spores over a field. To determine spore quantities, real-time PCR has been applied to analyze daily spore catch. These results were compared to data from parallel spore traps where hourly numbers of spores are enumerated by use of microscope. An attempt to backtrack an early infection of P. cubensis was made by producing trajectories to show where possible sources of infection may be located in the case of long distance distribution of spores by air. This work will be continued in 2008 and 2009, and the results will be used for better forecasting of downy mildew pathogens in Norway.
Forfattere
Anne-Kristin Løes Benjamin Nölting Niels Heine Kristensen Roberto Spigarolo Carola Strassner Gun Roos Minna Mikkola Bent Egberg MikkelsenSammendrag
One of eight pilot projects in the European CORE Organic programme, innovative Public Organic food Procurement for Youth, (iPOPY) will study efficient ways of implementing organic food in public serving outlets for young people (2007-10). By analysing practical cases of school meal systems and other food serving outlets for youth, we will identify hindrances and promoting factors in the participating countries (Denmark, Finland, Italy and Norway). Policies, supply chains, certification systems, the young consumers" perception and participation, and health effects of implementation of organic policies and menus are focussed in iPOPY. The main aim is to suggest efficient policies and comprehensive strategies to increase the consumption of organic food among young consumers in a public setting, and fostering sustainable nutrition. Interdisciplinary project tools under development will be presented along with the first project results, which will be available by June 2008.
Forfattere
Venche Talgø Thomas Cech Gary Chastagner Iben Margrete Thomsen Kathy Riley Kurt Lange Arne StensvandSammendrag
Current-season needle necrosis (CSNN) is a poorly understood disease with significant impact on the marketability of fir (Abies spp.) Christmas trees and boughs in North America and Europe. Initial symptoms appear on needles soon after bud break as tan to yellow-coloured spots, which turn reddish brown during the summer. The symptoms are observed on noble fir (A. procera), nordmann fir (A. nordmanniana) and grand fir (A. grandis) on both continents. The etiology of CSNN is unknown. In the USA, Ireland and Denmark, research has indicated that CSNN is a physiological disorder. Isolation and examination of host tissue at the onset of symptoms failed to identify a pathogen. In the USA, foliar applications of very high rates of calcium, or shading noble and grand fir shoots during shoot elongation, significantly reduced CSNN damage. Research in the USA and Denmark also showed that CSNN susceptibility in noble fir is under strong genetic control. In Germany, the fungus Kabatina abietis Butin & Pehl sp. nov. was isolated for the first time in 1992 from grand fir needles with CSNN symptoms, and later from nordmann and noble fir. K. abietis was also recently isolated from symptomatic nordmann fir needles on samples from Austria, Norway and Denmark. Given the uncertain etiology of CSNN, inoculation tests will be carried out in Norway, and fungicide trials will be performed in Austria, Denmark, Germany, Norway and the USA in 2008, in an effort to determine the potential role of K. abietis in the development of this disease.
Sammendrag
Phytophthora infestans is an important pathogen on potato and tomato during the winter seasons in the north of Vietnam and all the year around in Lam Dong province in the south of Vietnam. Data from earlier studies of isolates of P. infestans collected in 2002-2003 showed that the P. infestans population on tomato and potato from Vietnam still consist of the "old" population. However preliminary studies of P. infestans samples from 2007 indicate that this situation has started to change. Data from aggressiveness tests of P. infestans isolates on tomato and potato showed that the majority of isolates collected from tomato could not infect potato. All tested isolates originating from potato infected both hosts. From 2005-2007, field experiments in tomato and potato using IPM strategies for controlling late blight have been carried out in Lam Dong province and in Hanoi area (north of Vietnam). In these experiments, cultivars with different levels of late blight resistance and different fungicide dosages have been tested. Simple forecasting methods and sanitation procedures were also included in some of the experiments. In Lam Dong, strategies including 7 days fixed spray intervals with full dose of the fungicide mancozeb did not control late blight properly in tomato, and all 4 tomato experiments were terminated early. In the potato experiments use of a more modern fungicide could control late blight using reduced dosages. In the tomato experiments in the north no natural infection of late blight occurred during the experimental period.
Sammendrag
Phytophthora infestans is an important pathogen on potato and tomato during the winter seasons in the north of Vietnam and all the year around in Lam Dong province in the south of Vietnam. Data from earlier studies of isolates of P. infestans collected in 2002-2003 showed that the P. infestans population on tomato and potato from Vietnam still consist of the "old" population. However preliminary studies of P. infestans samples from 2007 indicate that this situation has started to change. Data from aggressiveness tests of P. infestans isolates on tomato and potato showed that the majority of isolates collected from tomato could not infect potato. All tested isolates originating from potato infected both hosts. From 2005-2007, field experiments in tomato and potato using IPM strategies for controlling late blight have been carried out in Lam Dong province and in Hanoi area (north of Vietnam). In these experiments, cultivars with different levels of late blight resistance and different fungicide dosages have been tested. Simple forecasting methods and sanitation procedures were also included in some of the experiments. In Lam Dong, strategies including 7 days fixed spray intervals with full dose of the fungicide mancozeb did not control late blight properly in tomato, and all 4 tomato experiments were terminated early. In the potato experiments use of a more modern fungicide could control late blight using reduced dosages. In the tomato experiments in the north no natural infection of late blight occurred during the experimental period.