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.
2007
Forfattere
Lars Tørres Havstad Trygve S. AamlidSammendrag
Tiller demography and contribution to seed yield were studied in first year seed crops of Bromus inermis `Løfar" and Festuca pratensis `Salten" planted on different dates and with increasing plant densities (A: 15 or 18 Jun / 11 plants m-2, B: 15 or 30 July / 44 plants m-2, C: 15 August or 10 September /178 plants m-2) in field trials at Landvik, SE Norway, in 1998 and 1999. While the total tiller population in most crops increased until seed harvest, it decreased during panicle elongation in crops of Bromus inermis and Festuca pratensis that had reached 2000 and 3500 tillers m-2 in early spring, respectively. Except for the fact that many of the primary tillers of Bromus inermis died after producing barren stems, tillers formed in August and September had the greatest chance of becoming reproductive and produced the longest culms with the heaviest inflorescences in both species. Most tillers produced in winter or early spring either remained vegetative or died, but spring-emerging tillers contributed up to 30% of the total seed yield in early-established, low-density crops of Festuca pratensis. The results are discussed in relation to former papers suggesting that inter-tiller transfer of flower induction stimuli is possible in some perennial grasses. It is concluded that tillers produced in winter and spring contribute more to seed yield in Festuca pratensis than in Bromus inermis.
Forfattere
Unni AbrahamsenSammendrag
Foredraget ga en oversikt over havredyrkinga i Norge, i tidligere år og nå. Fordeler og utfordringer i havredyrkinga ble belyst, og hvilke muligheter som finnes for økt produksjon i Norge.
Forfattere
Philipp Gannibal Sonja Klemsdal Mark LevitinSammendrag
Alternaria tenuissima is a common pathogen on a number of plants described in several geographic regions of the world. Genetic variation within and between Russian Far East, North West and Caucasus populations of A. tenuissima from wheat was examined. In addition, genetic differences between isolates from various hosts were estimated. In total, 101 isolates of A. tenuissima were studied using amplified fragment length polymorphism (AFLP) with four primer combinations. Wright"s fixation index (F-st), gene flow (N-m) and gene diversity (H-s) were calculated. AFLP banding patterns indicated significant genetic distance and at the same time a low level of gene flow between the Far East and the two other groups of isolates originating from the European part of country. The degree of similarity between the North West and Caucasus populations was very high, as was the migration rate. Isolates analysed by UPGMA-based cluster analysis were grouped according to location of origin but irrespective of plant host. Based on the F-st value, the group of isolates originating from wheat and barley were not found to differ significantly from each other.
Sammendrag
Mange av våre kulturmarksplanter er nå i tilbakegang, fordi leveområdene deres forandres og ødelegges når landskapet gror igjen, bygges ned eller dyrkes opp. Av våre ca 650-700 engplanter, regner vi med at omtrent halvparten av dem er helt avhengige av "eng" for å overleve. Engene i det norske landskapet er stort sett skapt av slått og beite og må brukes på tradisjonell måte hvis de skal opprettholdes. Som eksempel på en planteart som i dag er truet og avhengig av skjøtsel, kan vi nevne orkidéen svartkurle. Den mest optimale skjøtselen for denne arten er tradisjonell slått sent på sommeren. Men det er ikke bare planter som er avhengig av de gamle kulturmarkene. Den nye norske "rødlisten" (over truete arter) fra 2006 viser at ca. 35% av våre trua plante- og dyrearter faktisk er knyttet til kulturlandskapet. Dette understreker hvor viktig de gamle kulturmarkene er for det biologiske mangfoldet! Og det forteller oss også at den nasjonale målsetningen om å stoppe tapet av biologisk mangfold innen 2010 blir vanskelig uten et aktivt landbruk og beitende husdyr!
Forfattere
Lise Hatten Ronald BjøruSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor Håkon SivertsenSammendrag
The topography of the earth influences the movements of parcels of air in the atmosphere. Wind systems blowing across mountain ridges sometimes excite stationary gravity wave systems behind and above ridges witrh a breath of about 10 km. The conceptual discussion in this paper is connected to the transport of wave energy in stationary gravity waves and stationary gravity inertia waves , where there are discontinuities in the parameters describing the vertical stratified atmosphere. The discussion is closely connected to two theorems by Eliassen and Palm (1961) showing that the vertical flux of wave energy is conserved throughout the atmosphere for a great class of systems. But the boundary conditions used by Eliassen and Palm (1961) in the gravity wave systems connecting the vertical layers in situations with discontinuities do not cover all possible physical situations of interest.
Forfattere
Tor Håkon Sivertsen Janis GailisSammendrag
The history of a web-based system for administrating data from a network of agrometeorological stations is shortly presented, and the module of this system containing the documentation of the instruments in this network is discussed in detail. The quality concept of meteorological data is the starting point in this discussion. The way of coupling the instruments and parameters on each meteorological station is shown, as well as use of this information by controlling and correcting meteorological data. Ideas of actor-network theory are discussed connected to future challenges of data integration and use of data from different sources in applications.
Forfattere
Geir Kjølberg KnudsenSammendrag
Det er ikke registrert sammendrag
Forfattere
Therese With Berge Haldor Fykse Are H. AastveitSammendrag
A major obstacle to patch spraying of broad-leaved weeds in cereals is a cost-effective method to assess within-field heterogeneity of the weed population. One method could be a camera mounted in front of the spraying vehicle, online image analysis, and field sprayer shifting between "on" and "off" as the predefined weed damage threshold level is reached. Because such a camera will capture a very limited area (
Forfattere
Therese With Berge Are H. Aastveit Haldor FykseSammendrag
En bildealgoritme ("WeedFinder") som automatisk estimerer ugrasmengde i digitale fargebilder ble evaluert.