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.
2010
Authors
Tove Maria Østensvik Petter Nilsen Kaj Bo VeierstedAbstract
No abstract has been registered
Authors
Trond HofsvangAbstract
Two Malaise traps were set up at Ås, Southern Norway, during the growing seasons 1992-1997, one trap in an organic grown barley field and one in its boundary. Totally 23 species of Tipulidae (Diptera) were identified, of these eight species belonged to the genus Nephrotoma Meigen, 1803. Of the total specimens collected 93% of the males and 88% of the females belonged to this genus. Comparing the two traps, 80% of the Nephrotoma specimens were recorded in the organic field. It is discussed if larvae of Nephrotoma spp. in Norway can be potential pests in agricultural crops as reported from other countries. To Malaisefeller ble plassert ut i Ås i vekstsesongene 1992-1997, en i en økologisk dyrket byggåker og en i kanten av åkeren. Totalt ble 23 arter av stankelbein (Tipulidae, Diptera) identifisert, 8 av disse tilhørte slekten Nephrotoma. Av det totale antall individer som ble samlet inn, var 93 % av hannene og 88 % av hunnene av slekten Nephrotoma. 80 % av Nephrotoma-individene ble funnet i den fellen som sto ute i byggåkeren. I mange andre land er larver av Nephrotoma-arter skadedyr på mange kulturplanter i jordbruket, og det diskuteres om disse artene kan opptre som skadedyr i Norge.
Authors
Ingunn ØvsthusAbstract
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Authors
Tore SkrøppaAbstract
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Authors
Stein Michael Tomter Gro Hylen Jan-Erik NilsenAbstract
No abstract has been registered
Authors
Åsmund AsdalAbstract
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Abstract
Abstract Two field trials are reported on Jerusalem artichoke (Helianthus tuberosus L.). Firstly, twenty genetic variants were compared with respect to crop yield, morphology and content of sugars and FOS in order to find genotypes suitable for Norwegian production. The highest yield and highest number of tubers per plant was obtained in early flowering variants, e.g. the white variant ‘Tysnes" gave 1.72 kg tubers per plant (28.7 t haa-1). Such early variants had markedly lower portion of smooth tubers. Late variants gave the most preferable tuber shape, but the yield was only half of the most productive ones. Dry matter content (%DM) varied from 19.67 to 23.33. Only a weak correlation was found between dry matter content and total content of FOS (r = 0.255) in the tubers. The mean content of FOS including sucrose through all variants was found to be 11.6 g 100g-1 FW or 55.0 g 100g-1 DW by measurement of non-hydrolyzed plant. Average chain length of FOS in the tubers was found to be DP3.9. There was no difference in tuber FOS content between flowering and non flowering variants. A second trial investigated the above ground part of one flowering and two late or non flowering variants during the growing season. Highest biomass was found for the late or non flowering variants when harvested in September. Total dry matter at time of harvest were found to be 0.21, 0.55 and 0,44 kg plant-1 for the variants ‘Dagnoytral", ‘Elverum" and ‘Krogerup" respectively (5.4, 14.1 and 11.3 t haa-1). At time of harvest stalks of ‘Elverum" and ‘Krogerup" contained 1.25 and 0.77 % fructose (DM) and 3.40 and 1.91 % sucrose. The content of soluble carbohydrates was found to be highest in stalks in August (sucrose and FOS major compounds).