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.
2020
Authors
Gunda Thöming Sándor Koczor Ferenc Szentkirályi Hans Ragnar Norli Marco Tasin Geir Kjølberg KnudsenAbstract
In a field-trapping experiment with plant volatiles, we observed notably high attraction of green lacewing (Chrysotropia ciliata) males to the compound p-anisaldehyde. Based on this finding, we initiated the present study to elucidate this phenomenon and to investigate the chemical ecology of C. ciliata. Scanning electron microscopy revealed elliptical glands abundantly distributed on the 2nd to 6th abdominal sternites of C. ciliata males, whereas females of the species completely lacked such glands. No p-anisaldehyde was found in extractions of body parts of C. ciliata. Methyl p-anisate and p-methoxybenzoic acid were identified exclusively in the extract from abdominal segments 2–8 of males. Field-trapping experiments revealed no attraction of C. ciliata to either methyl p-anisate or p-methoxybenzoic acid. In contrast, males showed marked attraction to p-anisaldehyde in the field and antennae showed strong responses to this compound. Headspace collections in the field from living insects in their natural environment and during their main daily activity period indicated that p-anisaldehyde was emitted exclusively by C. ciliata males. Our overall results suggest that p-anisaldehyde might serve as a male-produced pheromone that attracts conspecific C. ciliata males. Here, we discuss hypotheses regarding possible mechanisms involved in regulation of p-anisaldehyde production, including involvement of the compounds methyl p-anisate and p-methoxybenzoic acid, and the potential ecological function of p-anisaldehyde in C. ciliata.
Abstract
There is a need both in organic farming and on farms using integrated pest management for non-chemical measures that control the perennial weed flora. The effect of mechanical weeding and fertilisation on perennial weeds, fungal diseases and soil structure were evaluated in two different experiments in spring cereals. Experiment I included six strategies. The first strategy was (1) without specific measures against perennial weeds. The other strategies encompassed one or two seasonal control measures; (2) rhizome/root cutting with minimal soil disturbance in autumn, (3) hoeing with 24 cm row spacing, (4) combined hoeing and disc harrowing in autumn, (5) ‘KvikUp’ harrowing in spring, and (6) ‘KvikUp’ harrowing in spring and autumn. Experiment II included factor (i) inter-row hoeing and (ii) fertilisation level. This experiment included the comparison between normal row spacing (12 cm) with weed harrowing versus double row spacing (=24 cm) in combination with inter-row hoeing and 4 fertilisation levels (50–200 kg N ha−1). In experiment I the strategies consisting of no or one direct weed control measure (1, 2, 3 and 5) clearly did not control the perennial weeds. The two seasonal control measures (4 and 6) gave a satisfactory weed control and highest crop yield. The combination of best weed control and no measured harmful effects on soil structure or increase of fungal diseases may explain the highest yields for these strategies. In Experiment II, hoeing and 24 cm spacing gave less perennial biomass compared to 12 cm spacing. Grain yields increased linearly with increasing nitrogen input. The study shows that both inter-row hoeing and weed harrows, are important elements in integrated pest management practice and organic farming. In addition, our results indicate that efficient mechanical weeding is possible without harmful effects in crop rotation consisting of various spring cereals as regards soil structure and plant health.
Abstract
Ornamental jewelweed (Impatiens glandulifera Royle) is an alien invasive plant in Europe. This annual plant often grows in riparian habitats where herbicides are prohibited. Several studies have reported the negative effect on ecosystem and ecosystem services by this species. However, limited research is published on control measures and the aim of our study was to explore use of hot water and cutting to control I. glandulifera. A lab experiment showed that the lethal water temperature for seed was between 45 and 50 C. In a pot experiment with seeds in soil, emergence of I. glandulifera was reduced by 78% and 93% compared with the untreated control with volumes of hot water (80 C) of 7.2 and 14.5 L m−2, respectively. When treatments were conducted on relatively tall plants (almost 60 cm) in late June, hot water gave significantly better control than cutting. Compared with an untreated control, I. glandulifera cover was reduced by 97% and 79% after hot water and cutting, respectively. Application of hot water to smaller (<40 cm) and less developed plants (BBCH 12–13) in early June and cutting of plants with visible flower buds (mid-July) led to no significant difference in cover. Compared with an untreated control, I. glandulifera cover was reduced by 99% (cut below first node) and 91% (hot water and cut above first node). When relatively tall plants (almost 60 cm) were treated, hot water use was high (31.1 L m−2) and required twice as many work hours (4.8 min m−2) as cutting (2.4 min m−2). When smaller plants (<40 cm) were targeted, work hours and hot water use were reduced to 2.1 min m−2 and 13.7 L m−2, respectively.
Authors
Hanno Sandvik Olga Hilmo Snorre Henriksen Reidar Elven Per Arvid Åsen Hanne Hegre Oddvar Pedersen Per Anker Pedersen Heidi Solstad Vigdis Vandvik Kristine Bakke Westergaard Frode Ødegaard Sandra Charlotte Helene Åström Hallvard Elven Anders Endrestøl Øivind Gammelmo Bjørn Arild Hatteland Halvor Solheim Björn Nordén Leif Sundheim Venche Talgø Tone Falkenhaug Bjørn Gulliksen Anders Jelmert Eivind Oug Jan Henry Sundet Elisabet Forsgren Anders Gravbrøt Finstad Trygve H. Hesthagen Kjell Harald Nedreaas Rupert Wienerroither Vivian Husa Stein Fredriksen Kjersti Sjøtun Henning Steen Haakon Hansen Inger Sofie Hamnes Egil Karlsbakk Christer Magnusson Bjørnar Ytrehus Hans Christian Pedersen Jon Swenson Per Ole Syvertsen Bård Gunnar Stokke Jan Ove Gjershaug Dag Dolmen Gaute Kjærstad Stein Ivar Johnsen Thomas Correll Jensen Kristian Hassel Lisbeth GederaasAbstract
1. Due to globalisation, trade and transport, the spread of alien species is increasing dramatically. Some alien species become ecologically harmful by threatening native biota. This can lead to irreversible changes in local biodiversity and ecosystem functioning, and, ultimately, to biotic homogenisation. 2. We risk-assessed all alien plants, animals, fungi and algae, within certain delimitations, that are known to reproduce in Norway. Mainland Norway and the Arctic archipelago of Svalbard plus Jan Mayen were treated as separate assessment areas. Assessments followed the Generic Ecological Impact Assessment of Alien Species (GEIAA) protocol, which uses a fully quantitative set of criteria. 3. A total of 1519 species were risk-assessed, of which 1183 were species reproducing in mainland Norway. Among these, 9% were assessed to have a severe impact, 7% high impact, 7% potentially high impact, and 49% low impact, whereas 29% had no known impact. In Svalbard, 16 alien species were reproducing, one of which with a severe impact. 4. The impact assessments also covered 319 so-called door-knockers, i.e. species that are likely to establish in Norway within 50 years, and 12 regionally alien species. Of the door-knockers, 8% and 10% were assessed to have a severe and high impact, respectively. 5. The impact category of most species was driven by negative interactions with native species, transformation of threatened ecosystems, or genetic contamination. The proportion of alien species with high or severe impact varied significantly across the different pathways of introduction, taxonomic groups, time of introduction, and the environments colonised, but not across continents of origin. 6. Given the large number of alien species reproducing in Norway and the preponderance of species with low impact, it is neither realistic nor necessary to eradicate all of them. Our results can guide management authorities in two ways. First, the use of quantitative assessment criteria facilitates the prioritisation of management resources across species. Second, the background information collected for each species, such as introduction pathways, area of occupancy and ecosystems affected, helps designing appropriate management measures.
Authors
Hanno Sandvik Olga Hilmo Snorre Henriksen Reidar Elven Per Arvid Åsen Hanne Hegre Oddvar Pedersen Per Anker Pedersen Heidi Solstad Vigdis Vandvik Kristine Bakke Westergaard Frode Ødegaard Sandra Charlotte Helene Åström Hallvard Elven Anders Endrestøl Øivind Gammelmo Bjørn Arild Hatteland Halvor Solheim Björn Nordén Leif Sundheim Venche Talgø Tone Falkenhaug Bjørn Gulliksen Anders Jelmert Eivind Oug Jan Henry Sundet Elisabet Forsgren Anders Gravbrøt Finstad Trygve H. Hesthagen Kjell Harald Nedreaas Rupert Wienerroither Vivian Husa Stein Fredriksen Kjersti Sjøtun Henning Steen Haakon Hansen Inger Sofie Hamnes Egil Karlsbakk Christer Magnusson Bjørnar Ytrehus Hans Christian Pedersen Jon Swenson Per Ole Syvertsen Bård Gunnar Stokke Jan Ove Gjershaug Dag Dolmen Gaute Kjærstad Stein Ivar Johnsen Thomas Correll Jensen Kristian Hassel Lisbeth GederaasAbstract
No abstract has been registered
Abstract
The EU has developed a Directive on Sustainable Use of Chemical Pesticides (2009/128/EC) (SUD) that aims to enhance the use of non-chemical alternatives to pesticides like microbial plant protection products (PPP). The number of authorized microbial PPP for plant protection has increased globally during the last decade. There is, however, variation between different countries. Sweden and Denmark have for example each authorized 20 microbial PPP while Norway has only authorized four microbial PPP. Norway has also received significantly fewer applications for authorization of microbial PPP than the other Scandinavian countries. We explore possible explanations for the observed differences. Our results show that that the regulations in the three countries had similar requirements for the authorisation of microbial PPP. The size of the market is somewhat smaller in Norway than in Sweden and Denmark, and could therefore explain some of the differences. We suggest, however, that the most important explanation is implementation differences in terms of different decisions made in the authorization process. By comparing the authorization process for three microbial PPP in the Scandinavian countries, we found that Norway used more time for the product authorization decisions. Norway assess the same types of microbial PPP more restrictively with respect to environmental aspects and especially human health risks.
Authors
Anna Filipiak Solveig Haukeland Kamila S. Zając Dorota Lachowska-Cierlik Bjørn Arild HattelandAbstract
A survey of helminths associated with terrestrial slugs focusing on the invasive Arion vulgaris and the native A. ater was conducted on populations from France, Germany, Netherlands, Norway and Poland. In total, 648 terrestrial slugs were collected from 18 sample sites, and identified by means of morphological examination, dissection of genitalia and molecular analysis using mitochondrial DNA. In addition to A. vulgaris and A. ater, also A. vulgaris/A. rufus hybrids and A. ater/A. rufus hybrids were collected. Helminth species were identified based on morphological features and sequencing of the 18S and ITS rDNA regions. The parasites included four nematode species: Alloionema appendiculatum, Angiostoma sp., Phasmarhabditis hermaphrodita, Entomelas sp., two trematode species: Brachylaima mesostoma, Eurytrema sp., and one cestode (tapeworm) species: Skrjabinia sp. Alloionema appendiculatum was the most common helminth in the investigated slug populations. Furthermore, we found higher prevalence of trematodes in the invasive A. vulgaris compared with the native A. ater, while differences in the prevalence for nematodes were not as clear.
Abstract
The worldwide decline in bees and other pollinating insects is a threat to biodiversity and food security, and it is urgent to take action. One of the causes for insect decline is the use of harmful pesticides in agriculture. In the presented study we use Norwegian apple production as a case-study to investigate which of the three groups: farmers, consumers and public authorities, have the most responsibility for protecting bees against harmful pesticides. The questions are investigated empirically with qualitative data material from Norwegian apple farmers, consumers and public authorities, and survey data from consumers and farmers. Our results indicate that consumers see public authorities and farmers as equally responsible for protecting the bees, while farmers are inclined to see themselves as more responsible. Neither groups consider consumers to have any large responsibility. Among the consumers there is also a high level of trust in both farmers and public authorities.
Authors
Haftamu Gebretsadik Gebrehiwot Jens Bernt Aune Ole Martin Eklo Torfinn Torp Lars Olav BrandsæterAbstract
Allelopathic potential of 10 teff varieties was assessed in laboratory experimentation (conducted in NIBIO, Norway), and determined with an agar-based bioassay using ryegrass and radish as model weeds. Field experiments were conducted in Tigray, Ethiopia during 2015 and 2016 to identify the most important agronomic traits of teff contributing to its weed competitive ability. A split plot design with three blocks was used considering hand weeding as the main plot and varieties as the subplot. Randomized complete block design (RCBD) with four blocks was used in the laboratory experiment. The highest potential allelopathic activity (PAA) and specific potential allelopathic activity (SPAA) were recorded from a local landrace with an average PAA value of 11.77% and SPAA value of 1.21%/mg respectively, when ryegrass was used as the model weed. ‘Boset’ had the highest average PAA value of 16.25% and an SPAA value of 1.53%/mg, when using radish as the model weed. The lowest PAA and SPAA values were recorded from ‘DZ-Cr-3870 when using ryegrass and radish as model weeds. Days to emergence, height, tiller no./plant, biomass yield, and PAA of the crop significantly contributed to the variance of the weed biomass, cover, and density. Hence, they were the most important agronomic traits enhancing the competitive ability of teff.
Authors
Haftamu Gebretsadik Gebrehiwot Jens Bernt Aune Jan Netland Ole Martin Eklo Torfinn Torp Lars Olav BrandsæterAbstract
Teff is a staple and well adapted crop in Ethiopia. Weed competition and control have major effects on yields and economic returns of the crop in the country. Among the weed management methods, development and use of weed competitive teff varieties remain the cheapest and most sustainable weed management option. Ten teff varieties were tested for their weed competitive ability in two locations. Treatments were applied using a split plot design with three blocks at each location for two consecutive seasons. Hand weeding and non-weeded treatments were applied to whole plot treatments with teff varieties assigned as split plots within the whole plot. The main objective was to determine relative competitive ability among teff varieties. Results showed that teff varieties showed significant variation in their weed competitive abilities. The varieties ‘Kora’ and ‘DZ-Cr-387’ significantly reduced weed density, dry weight, and cover more than the other teff varieties. They also had the lowest yield losses with a loss of 6% in biomass yield and 18% in grain yield recorded from ‘Kora’ and a loss of 17% in biomass yield and 21% in grain yield recorded from ‘DZ-Cr-387’. Therefore, they showed the highest weed competitive ability compared to the other varieties.