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
Sammendrag
Histological properties of the graft union between a rootstock and scion may provide a mechanistic explanation why dwarfing rootstocks are able to reduce the growth of the tree. In order to investigate the relationship between growth and the amount of functional xylem tissue of potted sweet cherry trees, an experiment was conducted during 2002-2003. One year old field budded and bench grafted (from greenhouse) sweet cherry trees of the cultivars Van, Ulster and Lapins in all combinations of the three rootstocks Prunus avium seedling, Colt and Gisela 5 were grown in pots for two growing seasons. After shoot extension had terminated when trees were in full leaf the second year, the total growth of the different parts of the trees and the functional area using safranin staining were measured. The total mass production (tree dry weight, the length of two year old wood and number of leaves) was significantly larger in the budded trees. Similarly the trunk cross sectional area was significantly larger 10 cm above and in the middle of the graft union, but not 10 cm below it. The Colt trees were the most vigorous followed by the seedling and Gisela 5. Minor differences between the different cultivars were registered. Xylem staining with aqueous safranin combined with quantitative image analysis showed that the rootstock stem had a higher proportion of stained tissue than the scion stem. Sections taken in the middle of the graft tissue and 10 cm above showed that the proportion of stained tissue declined proportionally with the distance from the roots. The total area of stained stem xylem was larger for the two vigorous rootstocks compared to Gisela 5. Small differences were observed between cultivars and propagation methods.
Sammendrag
Combinations of covering and fungicide applications were tested on two sweet cherry cultivars; Van during two years (2001 and 2002) and Lapins three years (2001"2003). The following treatments were tested in 2001 and 2002: (i) covering during flowering and from 5 to 6 weeks prior to harvest and throughout harvest, no fungicides applied, (ii) as (i) but fungicides were applied once or twice between the two covering periods, (iii) covered 5 to 6 weeks prior to harvest and throughout harvest, fungicides applied two or three times prior to covering, and (iv) uncovered throughout the season, fungicides applied two or three times in the period from flowering towards harvest. In 2003, the trees were covered only from 5 to 6 weeks prior to harvest and throughout harvest. Both treatments that year received fungicide applications during flowering, but one of the treatments was left unsprayed during the green fruit period prior to covering. Every combination of covering and fungicide applications reduced total fruit decay at harvest significantly compared to a full fungicide programme and no covering. In three of four trials when the trees were covered during flowering and prior to harvest, and fungicide applications were omitted in the green fruit phase between the covering periods, no significant increase in fruit rot occurred compared to treatments where fungicides were applied. However, in one trial there was a significant increase in fruit rot by leaving out one fungicide spray during that intermittent period. Furthermore, if fungicides were only applied during flowering and not on green fruit before covering in 2003, a significant increase in fruit rot occurred. Thus, leaving out fungicide applications during that supposedly less susceptible green fruit period, increased the risk of acquiring fruit rot. Applying fungicides during the green fruit stage significantly reduced the amount of brown rot in four of five trials and anthracnose in one of five trials. No negative effect on fruit quality was found from the extended covering periods. It can be concluded that covering effectively replaced fungicide applications during flowering and prior to harvest.
Forfattere
Eivind Vangdal Stein Harald Hjeltnes Mekjell MelandSammendrag
I eit felt med "Excalibur" og "Prinlew" plommer vart køyregangen dekka med kvit reflekterande duk for å betra ljostilhøva i trekruna. Duken låg i hagen frå 2 veker etter bløming til etter at plommene var hausta i midten av september. Der det ikkje var nytta reflekterande duk var fruktene nede på treet grønare, hadde mindre dekkfarge og lågare innhald av oppløyst turrstoff enn fruktene oppe i trekrunene. Fruktene frå tre som hadde stått over reflekterande duk var like godt farga og hadde same syrinnhald og fastleik om dei var hausta oppe eller nede på trea. Men det var også for desse trea høgare innhald av oppløyst turrstoff i fruktene oppe i trea i høve til dei som hadde vakse nedst i trea. Reflekterande duk gav jamnare mogning hjå plommene oppe og nede i trea. Dermed kan ein klara seg med færre haustingar. Temperaturen var ikkje heva der ein nytta duk, og duken svekka grasveksten i køyregangane.
Forfattere
Eivind Vangdal Stein Harald Hjeltnes Mekjell MelandSammendrag
Betre lystilhøve i frukttrea aukar veksten hjå tre og frukter, og fruktkvalitetsfaktorar som farge og oppløyst turrstoff vert betre. Sjølv om daglengda under norske veksttilhøve er lang, er den samla lystilgangen mindre enn på sørlegare breiddegrader pga den korte vekstsesongen. Metodar som aukar ljostilgangen, t.d. lysreflekterande duk under trea, vil vera gunstig for norsk fruktdyrking. Ein har prøvd ein voven plast duk (Extenday (R)) i frukthagar på Vestlandet. Der radavstanden var 4 m, har ein strekt ut 3m brei duk på bakken langs køyregangane og festa med gummiband til trea på kvar side. Der radavstanden var 5 m, nytta ein 4m brei duk. Duken låg ute frå midten av juni til etter hausting. Det var ingen temepratureffekt av duken. Men det var 5 gonger så mykje lys i trekruna hjå tre som sto i felt med reflekterande duk i høve til kontroll tre. I køyregangen var det 3 gonger så mykje lys over duk som i køyregangar med gras. I Aroma var eple frå tre frå felt med duk større, søtare og med meir raud dekkfarge enn frå kontroll trea. Det var særleg stor skilnad frå eple på dei nedte greinene. Med omsyn til fastleik og syreinnhald var det ikkje sikre skilnader. Men Streif-indeks viste at refleksduken framskunda mogninga.
Forfattere
Siv Grete Bjervamoen Martin E. Smith Leif E. Ollila Hans Geir Eiken Paul Eric Aspholm Alexander Kopatz Aspi Jouni Tanja Kyykkä Tuomo Ollila Pekka Sulkava Olga Makarova Natalia Polikarpova Ilpo KojolaSammendrag
Det er ikke registrert sammendrag
Forfattere
Lise Haug Tor-Gunnar AustjordSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor Gunnar Austjord Lise HaugSammendrag
Det er ikke registrert sammendrag
Forfattere
Celine ReboursSammendrag
Laminaria has been known in Asia, first as kunbu ("large cloth") and, more recently, as haidai ("sea ribbon"). Internationally, "kelp" is generally used. The main extracted products are alginate, iodine and mannitol, which are used in textile, printing, medical and food manufacturing industries. Laminaria in its whole is also used in a huge variety of products for human consumption. In Europe, the exploited species have been L. digitata, hyperborea and saccharina. Mostly harvested as source of saltworth and iodine, wild thallus have also been used as fertizers in agriculture. In 2005, Laminaria is still harvested as alginates sources in Norway (L. hyperborea : 153 906 t) and France (L. digitata : 74 778 t). No cultivation is actually in place. In the late 1920s, the commercial seaweed Laminaria japonica was introduced into China from Hokkaido (Japan). Although commercial production of kelp harvested from its natural habitat has been carried out in Japan for over a century, mariculture of this cold water species on a very large commercial scale has been realized in China in the 1950s. Since, the Chinese kelp production increased from about 60 000 t annually to over 4 millions tones in 2005, making China the world largest producer of Laminaria. The Chinese success of the kelp cultivation in Asia has mainly depended on the adoption of three important techniques: the floating raft method, low temperature cultivation of summer seedlings, and application of nitrogen fertilizer in the open sea. The Chinese methods that have made Laminaria production successful are shortly described in this poster.
Forfattere
Leif Sundheim May Bente Brurberg Trond Hofsvang Christer Magnusson Trond Rafoss Brita Toppe Anne Marte Tronsmo Bjørn ØklandSammendrag
This Pest Risk Assessment (PRA) of the fire blight bacterium Erwinia amylovora was initiated by a review or revision of a policy by the Norwegian Food Safety Authority. Fire blight was detected in Norway for the first time in 1986. The focus of infection was in and around the city of Stavanger in Rogaland county on the south west coast of the country. Mainly Cotoneaster bullatus and C. salicifolius were attacked. The disease was contained and finally eradicated from the area in 1992. However, in 2000 fire blight re-emerged, in the same county, on the island Karmøy, separated from the first outbreak by 25 km open sea. A new containment and eradication programme was started. Nevertheless the disease continued to spread to the north, mainly due to the movement of beehives contaminated with E. amylovora, from areas with diseased plants to areas free from fire blight with warm and humid weather conditions, favorable for the development of the disease. Fire blight has been detected in private gardens, around public buildings, in recreation grounds, along roads, and in rural areas in the coastal areas of the counties of Rogaland, Hordaland and Sogn og Fjordane. It has not been detected in nurseries, in fruit-growing areas, or in other parts of the country. The main hosts are still C. bullatus and C. salicifolius and some other Cotoneaster spp. Occasionally diseased Sorbus aria, Pyrachanta and apple and pear have been detected. Recently a very limited outbreak on C. bullatus and C. salicifolius was detected in the city of Kristiansand in Vest-Agder county. The endangered area, where presence of fire blight will result in economically important loss is the commercial fruit growing areas of Norway. If E. amylovora is introduced into the main fruit growing districts, it is expected that the damage and losses to commercial fruit production and nurseries will be minor, under the current phytosanitary regime in Norway. Relaxation of the regulations in force for fighting fire blight in Norway will increase the expected damage and losses to commercial fruit production and nurseries to a moderate level. Importation of fruit trees and fruit tree propagation material from countries where fire blight is established is not expected to increase the risk of fire blight in Norway significantly, given that appropriate phytosanitary requirements and quarantine are followed.
Sammendrag
Det er ikke registrert sammendrag