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
Lars Tørres Havstad Trygve S. Aamlid Trond Maukon HenriksenSammendrag
The marked for cereal cover crop straw and herbage seed straw has diminished in many seed production areas due to less lifestock. Seed growers therefore want to chop and return the straw both in the sowing year and in the seed harvest years. The objectives of this research were (1) to compare decomposition rates of straw of barley and wheat cover crops and timothy (Phleum pratense L.), meadow fescue (Festuca pratensis Huds.), and red clover (Trifolium pratense L.) seed crops, (2) to study the effect on soil microbial activity of adding mineral nitrogen or fresh leaves from undersown seed crops, and (3) to evaluate the effect of straw placement / soil contact on straw decomposition rates. Microbial activity / straw decomposition rates were evaluated by regular measurement of CO2 production in four laboratory incubation experiments lasting for 150-161 days. Microbial activity was always enhanced by adding straw on the soil surface. Straw of barley resulted in higher CO2 production than straw of wheat, while straw of red clover and meadow fescue resulted in higher CO2 production than straw of timothy. Inclusion of fresh leaves of white clover and timothy increased CO2 production during the first and second half of the incubation experiments, respectively. Neither in the sowing year nor in the seed harvest year was microbial activity stimulated by adding fertilizer nitrogen, but soil mineral nitrogen by the end of the experiments was higher after adding fertilizer or fresh leaves, and lower after adding grass seed straw. Presumably due to higher humidity, straw decomposition in a field experiment was higher in timothy stubble than in wheat stubble and higher at 2 cm than at 10 cm above the soil surface. For practical seed production, growers are recommended to leave short stubble, to chop the straw as finely as possible, and to distribute the straw evenly on the surface in close contact with soil particles.
Forfattere
jihong liu clarkeSammendrag
Dengue viruses (Flavivirus) are mosquito-borne human pathogens with a worldwide prevalence. There are four antigenically-related dengue virus serotypes, DEN-1 to DEN-4, which can cause serious problems of morbidity and mortality. Dengue is emerging rapidly as one of the most important public health problems in countries of the Asia-Pacific region with nearly 1.8 billion people in the region at risk, compared to an estimated total of 2.5 billion globally (WHO 2007). In India, dengue is now re-emerging as one of the most important health problems, with many outbreaks reported in different parts of the country during the past decade. The disease has resulted in widespread social and economic problems, especially among the poor who are the most vulnerable group. The lack of a dengue vaccine and antiviral drug makes it difficult to control and manage the disease. To combat dengue fever under the influence of global warming and climate change, multiple coping strategies including affordable vaccines, vector control, sanctions, law enforcement and public education are essential. This talk will present the development of a tetravalent dengue vaccine using tobacco plants as a green factory, and the social and economic benefits of the plant-production system will be discussed. Other coping strategies such as vector control and improvement of water quality will also be addressed.
Forfattere
R Nestby I Martinussen A Nes J RohloffSammendrag
Examination of European blueberry (EB) populations from different latitudes in Norway revealed differences in growth, fruit yield and fruit quality. Subpopulations from latitude 61, 64 and 69°N (respectively south, mid and north of Norway) showed different growth patterns when they were grown under similar conditions. The EB tended to grow longer shoots in 2009 at intermediate fertilization in half-cultivated forest fields fertilized in 2008 and 2009, while shoot number was not influenced by fertilization. Berry size and fruit yield in forest fields was not influenced by fertilization neither in 2008 nor in 2009. However, there were differences in yield between locations in both years and between soil conditions in 2008. Fertilized seedlings sawn in March 2008 and planted on farm land in July the same year, grew larger plants in 2009 compared with no fertilization, but developed no flowers. Content of sugar, anthocyanins, total phenols, and antioxidants was higher in Mid- and North - Norway compared to samples from the south in 2008 . Fruit quality parameters changed from early to late harvest in the ripening period (only samples from South Norway). Sugar content was highest at the early maturation stage, while anthocyanin levels were highest in the mid-harvest period and then declined. Antioxidant levels increased at later harvest dates, and data was clearly correlated with total phenol content but not with anthocyanins.
Sammendrag
Examination of European blueberry (EB) populations from different latitudes in Norway revealed differences in growth, fruit yield and fruit quality. Two northern and two southern clones of EB (from between 61-69 degrees N) were grown at 12 degrees C and 18 degrees under shourt (12 h) and long (24 h) days. The northern clones were able to grow rapidly at reasonable low temperatures when given 24 hour light, while the southern clones seemed to be adapted to shorter days and were not able to use the 24 h light efficiently. In the field EB tended to grow longer shoots in 2009 at intermediate fertilization in half-cultivated forest fields fertilized in 2008 and 2009, while shoot number was not influenced by fertilization. Berry size and fruit yield in forest fields was not influenced by fertilization neither in 2008 nor in 2009. However, there were differences in yield between locations in both years and between soil conditions in 2008. Fertilized seedlings sawn in March 2008 and planted on farm land in July the same year, grew larger plants in 2009 compared with no fertilization, but developed no flowers. Content of sugar, anthocyanins, total phenols, and antioxidants was higher in Mid- and North- Norway compared to samples from the south, in 2008. Fruit quality parameters changed from early to late harvest in the ripening period (only samples from South Norway). Sugar content was highest at the early maturation stage, while anthocyanin levels were highest in the mid-harvest period and then declined. Antioxidant levels increased at later harvest dates, and data was clearly correlated with total phenol content but not with anthocyanins. Berries produced at 12 degrees had significantly higher % sugars (sucrose, fructose and glucose), phenolic acids and total phenols than berries produced at 18 degrees.
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
Jack D’Arcy E. Dunaevskaya Jim Treasurer Oddvar Ottesen Julie Maguire Nina Zhuravleva Åsbjørn Karlsen Celine ReboursSammendrag
The use of wrasse (F. Labridae) as biological cleaner-fish in the control of salmon lice has been demonstrated in a number of studies and they are successfully used on a large scale, with over two million wrasse being caught and stocked annually, in commercial salmon farms in Norway. Increasingly, efforts are being made to produce commercial stocks of wrasse for use on farms and an EU Northern Periphery Project entitled "Ecofish" has been established to develop the technologies for spawning and rearing the most promising cleaner fish, ballan wrasse, in captivity with dedicated production hatcheries will be established in Ireland, Norway and Scotland. This project will also look into the management of ballan wrasse in salmon cages in order to achieve the effective removal of lice. As part of the Ecofish work programme, this study examined the embryonic development of Ballan wrasse using material from a series of spawnings in Ireland and Norway. The overall development from fertilization to hatch was monitored and recorded and a standardized series of developmental stages are assigned, from zygote through cleavage, blastulation, gastrulation, segmentation to hatching: each with specific morphological landmarks. This standardization and the synchronization of the developmental stages will facilitate future studies with the species as we may be better able to compare the development rate of different geographic stocks and under different environmental conditions. The developing embryo was also staged at three different incubation temperatures; 10.5oC, 12.9 oC, and 16.5 oC with 50% hatched occurring at 171, 121 ands 96 hours post fertilisation respectively.
Forfattere
jihong liu clarkeSammendrag
The world population is expected to reach an estimated 9.2 billion by year 2050. Therefore, food production globally should increase by 70 percent in order to feed the world, while total arable land, which has reached its maximal utilization, may even decrease. Climate change adds yet another challenge to the food security problem. In order to feed the world in 2050, biotechnological advances in modern agriculture are essential. After the first green revolution, plant genetic engineering has offered a new tool to incease global crop production and this will continue to play an important role in modern agriculture to meet global challenges. To enhance crop biomass through improved agronomic traits and increase photosynthetic capacity via the chloroplast genome will be of importance in the years ahead. Chloroplast genome engineering, with several unique advantages, especially transgene containment, has made significant progress in the last two decades in various biotechnology applications including development of crops with high levels of resistance to insects, bacterial, fungal and viral diseases, different types of herbicides, drought, salt and cold tolerance, cytoplasmic male sterility, metabolic engineering, phytoremediation of toxic metals and production of many vaccine antigens, biopharmaceuticals and biofuels. Chloroplast genomes of several major crops have been transformed. These advances should promote crop productivity under a changing climate. This talk will give a brief insight into the current state of the art of plastid engineering in relation to agricultural production, especially for engineering of agronomic traits and improvement of crop biomass. The future direction of this technology and challenges for improvement of cereal crops to enhance their biomass for food security in a changing climate with special emphasis on elevated CO2 will be presented.
Forfattere
Håvard Eikemo David M. Gadoury Robert A. Spotts Oscar Villalta Piet Creemers Arne StensvandSammendrag
Estimates of ascospore maturity generated by models developed for Venturia pirina in Victoria, Australia (V-NV, V-SV), Oregon, USA (S), or for Venturia inaequalis in New Hampshire, USA (NH-1 and NH-2) were compared to observed ascospore release of V. pirina in 21 site/yr combinations. When plotted against degree-days, the lag phase and slope of all model estimates differed from observed release. The S model and V-SV model fit well with the data from Southern Victoria, while the data from Norway, Belgium and most years from Northern Victoria show a lag phase in the beginning of the season that was not present in the two models. In particular, data from the high-rainfall region of southern Victoria showed more variation between years than the other sites. Identifying the precise biofix (bud break) to initiate degree-day accumulation for the NH-2 model was problematic at both Australian sites, as regions with warm winters and minimal chilling exhibit protracted bud break. Linear regressions generated similar R2 values for the various models in many cases, but where differences were noted they more often favored the most recent model developed for V. inaequalis (NH-2). The NH-2 model also provided the most accurate estimates of 95% ascospore depletion (a key event in many disease management programs) for Norway, Belgium, and the higher rainfall areas of southern Victoria. Although developed for use in management of apple scab, the NH-2 model appears a reasonably accurate tool for predicting the release of ascospores by the pear scab pathogen, in particular in regions with moderate rainfall and colder winters.
Forfattere
Trygve S. Aamlid Oiva NiemeläinenSammendrag
The plant growth regulator trinexapac-ethyl (TE) has been evaluated in five registration trials in Finland and Norway. In 2007, TE was applied monthly at rates 0.023-0.090 kg a.i. ha-1 in a creeping bentgrass green trial and 0.057-0.339 kg a.i. ha-1 in two bluegrass/fescue fairway trials. Seasonal clipping yield reductions varied from 8 to 21 % in the green trial and from 0 to 25 % in the fairway trials; reductions were usually significant at two, but not at four weeks after application. Phytotoxic effects were observed at rates ≥ 0.113 kg a.i. ha-1 in one of the fairway trials, but TE resulted in less snow mould and faster green-up in 2008 in the other fairway trial and in the green trial. In a new green trial established 2008, weekly or biweekly applications of TE at rates 0.017-0.051 kg a.i. ha-1 reduced clippings by an average of 25 % and increased ball roll distance by an average of 6 %, however, differences among sprayed plots were not significant. In conclusion, we recommend that TE be approved for use on Scandinavian golf courses. Recommeded rates and application intervals are 0.023-0.046 kg a.i. ha-1 every 1-2 weeks on greens and 0.057-0.113 kg a.i. ha-1 every 2-3 weeks on fairways. The lower rates must always be used at the first application.
Forfattere
Trygve S. AamlidSammendrag
The plant growth regulator trinexapac-ethyl (TE) has been evaluated in five registration trials in Finland and Norway. In 2007, TE was applied monthly at rates 0.023-0.090 kg a.i. ha-1 in a creeping bentgrass green trial and 0.057-0.339 kg a.i. ha-1 in two bluegrass/fescue fairway trials. Seasonal clipping yield reductions varied from 8 to 21 % in the green trial and from 0 to 25 % in the fairway trials; reductions were usually significant at two, but not at four weeks after application. Phytotoxic effects were observed at rates ≥ 0.113 kg a.i. ha-1 in one of the fairway trials, but TE resulted in less snow mould and faster green-up in 2008 in the other fairway trial and in the green trial. In a new green trial established 2008, weekly or biweekly applications of TE at rates 0.017-0.051 kg a.i. ha-1 reduced clippings by an average of 25 % and increased ball roll distance by an average of 6 %, however, differences among sprayed plots were not significant. In conclusion, we recommend that TE be approved for use on Scandinavian golf courses. Recommeded rates and application intervals are 0.023-0.046 kg a.i. ha-1 every 1-2 weeks on greens and 0.057-0.113 kg a.i. ha-1 every 2-3 weeks on fairways. The lower rates must always be used at the first application.