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.
2010
Forfattere
Atle Wibe Anna-Karin Borg-Karlson Jerry Cross Lene SigsgaardSammendrag
One of the major pests on cultivated strawberry in northern part of Europe is the strawberry blossom weevil, Anthonomus rubi. The weevils deposit eggs in the flower buds before it sever the buds from their stalks. This may lead to a direct loss of crop of more than 50%. To develop effective plant protection method against A. rubi funnel traps baited with the sex aggregation pheromone and plant volatiles were used for trapping weevils in the fields. The sex pheromone blend used in the study was a mixture of Grandlure I, Grandlure II and Lavendulol (ratio 1:4:1). Plant volatiles emitted by the strawberry plants were collected using SPME and identified by GC/MS. These chemical analyses identified several compounds present in different quantities. The sex pheromone blend and selected plant volatiles were tested in fields either separately or in different mixtures. The field trials were carried out during a three year period where the last year aimed to optimise the mixture used in the previous years by adding more test compounds and testing the most potent compound at different concentrations. To improve insect catch rates modified traps were also tested. The study sites were in Norway, Denmark and in the UK. General high catch rates were achieved at three different study sites in Norway due to high weevil density. The results from these fields, supported by the results from the fields with lower catch rates, were in accordance with each other. The main finding was that traps baited with some identified plant volatile compounds and the sex pheromone blend increased the catch rates compared to traps bated with single a plant compound or the sex pheromone blend alone. The results show also that the concentration of the plant volatiles relative to the pheromone concentration is important for attracting weevils to the traps. This study has shown that it is important to bait insect traps with both sex aggregation pheromones and plant volatiles at the correct level to achieve significant catch rates of A. rubi. Hopefully, the results will generate knowledge important for developing new plant protection method for strawberry without using insecticides.
Sammendrag
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Sammendrag
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Forfattere
Tatsiana Espevig Michelle DaCosta Chenping Xu Lindsey Hoffman Trygve S. Aamlid Anne Marte Tronsmo Bruce B. Clarke Bingru HuangSammendrag
Freezing tolerance is a major component of winter hardiness of perennial grasses. Velvet bentgrass showed the same freezing tolerance as creeping bentgrass. Acclimation at temperatures above 0 ºC was associated with accumulation of nonstructural carbohydrates and enhanced plant survival after freezing. Acclimation at 2 ºC for 4 wk was more effective than for 2 wk and resulted in higher concentrations of fructans. Additional subzero acclimation at -2 ºC resulted in a reduction in fructans and higher concentration of reducing sugars; however, there was no additional improvement in freezing tolerance. Protein analysis was performed using 2-D polyacrylamide gel electrophoresis. Nineteen protein spots were responsive to acclimation. Thirteen proteins were identified. Identified proteins belonged to metabolism, energy, disease/defence, and secondary metabolism functional groups.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Today the spruce bark beetle Ips typographus is always univoltine in Northern Europe including Norway and completes development from egg to adult between May and August. Further south in Europe, development is bivoltine with the completion of two generations in most years. A temperature-driven developmental model suggests that by 2070-2100 the voltinism of I. typographus will change dramatically in Norway. If summers become only 2.5°C warmer than today bivoltinism can be expected every single year in the major spruce growing areas in S-Norway. This is likely to have dramatic effects on forestry since two generations per year will give two, instead of one, attack periods each summer. In addition to increasing the number of attacked trees the effect of the attacks may also be more severe, as Norway spruce is more susceptible to beetle attacks later in the summer. However, climate change will probably also change the phenology of Norway spruce and thus its susceptibility to attack by I. typographus and its phytopathogenic fungal associates. We are currently modelling how tree resistance varies with temperature and tree phenology in order to provide more well-founded advice to forest managers on the interaction between bark beetles and tree in a future climate.
Forfattere
Tatsiana Espevig Michelle DaCosta Trygve S. Aamlid Anne Marte Tronsmo Bruce B. Clarke Bingru HuangSammendrag
Cold acclimation plays a decisive role in turfgrass winter survival. This study was performed in collaboration with Rutgers University and University of Massachusetts (USA) to examine changes in carbohydrate levels in crown tissues during the first and second phases of cold acclimation in velvet bentgrass (Agrostis canina L.) and creeping bentgrass (A. stolonifera L.), and their association with freezing tolerance.. Four treatments representing different phases of cold acclimation were compared: (i) nonacclimated plants maintained at 18 °C/12 °C (day/night); (ii) plants acclimated at 2 °C for 2 wk and 250 μmol m-2 s-1 for 12 h photoperiod ; (iii) as treatment (ii) but for 4 wk; and (iv) as treatment (iii) plus additional sub-zero acclimation in the dark at -2 °C for 2 wk. Velvet bentgrass and creeping bentgrass showed no difference in lethal temperatures for 50% of the test population (LT50) as estimated by whole plant survival. Acclimation at 2 °C for 2 and 4 weeks resulted in accumulation of sucrose and fructans, and significantly lowered LT50 as compared with nonacclimated plants. Subzero acclimation resulted in less fructans, no difference in sucrose, and higher concentration of reducing sugars, but LT50 was not lower than after acclimation at 2 °C for 4 weeks.
Forfattere
Ellen Mosleth Færgestad Anette Moldestad Bernt Hoel Arne Oddvar Skjelvåg Anne Kjersti UhlenSammendrag
Det er ikke registrert sammendrag
Forfattere
Lone Ross GobakkenSammendrag
An evident change in climate the last decades has been recorded, and combined effects of increased CO2, elevated temperature and altered precipitation regimes have been observed to represent a change to the fundamental drivers within ecosystems. Growth of moulds, both in nature and on man-made constructions and objects, will most likely increase due to changes in the climate. The survival, the reproduction, the dispersal and the geographic distribution of moulds are decided by both direct and indirect effects of climate change. Not only the moulds, but also their hosts and substrates, possible competitors and enemies will be affected by climate change. It is essential to understand the interactions between the members in these ecosystems to be able to control and predict future development of moulds. The effect of introducing new building directives, environmental friendly materials and products which are meant to oblige the demand for more climate friendly buildings and houses, is an aspect that may generate unexpected and unintended mould growth on man-made constructions and objects. Future research should focus on the interaction between the moulds, the hosts, the substrates and the climatic factors, and what implications future changes in building directives and housing policy will have on mould growth.
Sammendrag
Protected Landscapes (PLs) are increasingly used in Norway to conserve cultural (human modified) landscapes. In many cases the maintenance of agricultural activities in PLs is required to preserve landscape character. Whilst research exists on land conservation policies in general, the particular effects of PL on management and adjustment of the farms involved have not received attention in the literature. We present results from a questionnaire sent to owners of agricultural land within PLs in Norway. Whilst landowners were divided upon the effects of PLs on farm management, the economic situation of the farm was little affected. Furthermore, changes in farm management after the establishment of a PL did not seem to have been driven by the establishment of the PLs per se. Most importantly, farm management changes were related to potential options to develop the farm and its land. A statistical model showed that PL-farms did not differ significantly from farms outside PL in the development of their land use or animal husbandry. Our findings thus indicate that the establishment of PL played a minor role as a driving force of changes in farm management and farm income.