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.
2013
Abstract
The distribution of Leiopus nebulosus (Linnaeus, 1758) and L. linnei Wallin, Nylander & Kvamme, 2009, in Norway is discussed and depicted. Observations of host trees as well as information of substrate qualities and phenology are included.
Abstract
Originally, Trypophloeus dejevi (Stark, 1936) was described from Sakhalin Island in the Far East of Russia, and it remained undetected in Europe until 2009, when one Swedish specimen was found in the collection of the late Lars Huggert. This specimen was sampled in Northern Sweden in Torne Lappmark: Årosjokk, 67°52’ N/19°22’E, in 1968. In 2010, the species was found in five new localities in the same area. Here we present T. dejevi, recorded in 2012 as a new species to Norway and Finland. In Norway, galleries with beetles were found in Salix myrsinifolia Salisbury and in Finland Salix glauca L. was the observed host tree. Both are common willow species in Northern Fennoscandia. The distribution of the beetle within trunks of living Salix combined with a low population-density may be an explanation to why T. dejevi has been overlooked until now.
Authors
JC. Streibig J. Rasmussen D. Andùjar Therese With Berge D. Chachalis T. Dittmann R. Gerhards TM: Giselsson P. Hamouz C. Jaeger-Hansen K. Jensen RN. Jørgensen M. Keller M. Laursen HS Midtiby J. Nielsen S. Muller H. Nordmeyer H. Peteinatos A. Papadopolous J. Svensgaard M. Weis S. ChristensenAbstract
No abstract has been registered
Authors
Nina TrandemAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
BACKGROUND: To grow remontant strawberries at high latitudes in autumn is challenging because of short days and low light levels. Nevertheless, current day and night temperatures in Norwegian coastal areas up to 63 degrees N are normally sufficient for growth and fruit development till early October, and even higher temperatures can be expected in the future according to climatic scenarios, with potential to prolong the growing season. However, light would be a minimum factor. It is therefore of interest to examine the effects of providing supplemental light when photosynthetic active radiation (PAR) falls below critical level for development of high fruit quality. OBJECTIVE: To examine effects on fruit yield parameters, fruit tension, Brix° and arthropod numbers, in order to investigate the potential of LED lighting using diodes giving red and blue light, as a means to prolong the growing season at northern latitudes. METHOD: In this two-year study remontant strawberry cvs ‘Everest’ and ‘Rondo’ were grown in high polytunnels. Two LED lighting levels (LED100 and LED300) were applied from 7 Pm to 7 AM, whenever light intensity fell below 400 μmol m−2 s−1 from first week of September, and compared to ambient light (control). The LED300 was peaking at wavelengths of 460 nm and 660 nm, respectively blue and red, and the relation between blue and red light was 1 : 8; LED100 delivered similar wavelengths but the blue to red relation was 2 : 8. Fruit yield, soluble solids (Brix°), fruit firmness, temperature (°C), dew point (°C), and PAR light (μmol m−2 s−1) were recorded. The experimental design was block with four replications. The lamps were hung with the light source 40 cm above top of canopy, giving a PAR radiation at top of canopy of LED100 and LED300 of respectively 900 and 258 μmol m−2 s−1. RESULTS: LED improved fruit yield and quality, but more at 900 than at 258 μmol m−2 s−1. However, highest light level was probably beyond the saturation point for photosynthesis, at least in early morning and late evening and the last three weeks of the harvesting season, because of low temperatures. Some fruit yield was not harvested because of too low temperatures to achieve ripen fruits after mid-October. Arthropods were sampled from ‘Rondo’ leaves 2–3 times per season, and aphids, spider mites and predatory mites (introduced) were the most numerous groups. LED significantly decreased the number of spider mites in the autumn. CONCLUSIONS: LED lighting has potential as light source growing remontant strawberries in high polytunnels, when PAR radiation is below 400 μmol m−2 s−1. However, to benefit fully of the light it would be necessary to grow the plants in winter tunnels and add heating. That would increase the yields significantly compared with our results.
Authors
Nina TrandemAbstract
No abstract has been registered
Authors
Line Emilie Sverdrup Christine Bjørge Ole Martin Eklo Merete Grung Torsten Källqvist Ingeborg Klingen Marit Låg Edgar Rivedal Erik Ropstad Steinar ØvrebøAbstract
No abstract has been registered
Authors
Line Emilie Sverdrup Christine Bjørge Ole Martin Eklo Merete Grung Torsten Källqvist Ingeborg Klingen Marit Låg Erik Ropstad Steinar ØvrebøAbstract
No abstract has been registered
Authors
Line Emilie Sverdrup Christine Bjørge Ole Martin Eklo Merete Grung Torsten Källqvist Ingeborg Klingen Marit Låg Erik Ropstad Steinar ØvrebøAbstract
No abstract has been registered