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.
2008
Sammendrag
The environmental control of flowering in the perpetual-flowering (everbearing) diploid strawberry Fragaria vesca ssp. semperflorens cultivars 'Rugen' and 'Baron Solemacher' has been studied in controlled environments. Seed-propagated plants were exposed to 10-h short-day (SD) and 24-h long-day (LD) conditions at temperatures ranging from 9 degrees - 27 degrees C. The results revealed a quantitative LD response of flowering that increased in strength with increasing temperature, to become almost obligatory at 27 degrees C. Occasional runner formation was observed in SD at high temperature, conditions which were inhibitory to flowering, demonstrating that runnering ability is not completely lost in these genotypes. A comparison with the perpetual-flowering octoploid F X ananassa 'Elan', in one experiment, demonstrated an identical LD X temperature interaction in the two species. The results are discussed in relation to available information on the genetics of flowering habits in the two species. Since seasonal flowering types of F vesca and E X ananassa have also been shown to share a principally identical flowering response, controlled by SD and low temperature, it is concluded that a remarkably similar flowering control system is present in the diploid F vesca and the octoploid F. X ananassa. Despite the large genetic differences between the two species, and regardless of the origin of the cultivars, the seasonal flowering types are all SD plants, while their perpetual-flowering counterparts all appear to be LD plants. In both cases, there is a pronounced interaction with temperature; the photoperiodic responses increasing with increasing temperature, in both cases. This raises the question whether a common genetic flowering control system is present in both species.
Sammendrag
Remonterende jordbærsorter er langdagsplanter, og er dermed svært godt tilpasset våre lange, lyse sommerdager. Sortene har stort avlingspotensiale og bærer gjennom en lang sesong. I et sortsforsøk ved Bioforsk Kise i 2006 og 2007, ble sju remonterende sorter sammenlignet med Korona. I 2007 ble det høstet mer enn 800 gram pr. plante for den beste sorten etter høsting fra 18. juni til 15. oktober. Vi trenger imidlertid bedre remonterende sorter før disse vil få sitt store gjennombrudd hos oss.
Sammendrag
The effect of night temperature on short day (SD) floral induction has been studied in three June-bearing strawberry cultivars of different geographic origin and compared with yield performance in the cool Nordic environment. At the optimum day temperature of 18 degrees C, the SD flowering response of the cultivars 'Florence' and 'Korona' increased significantly with increasing night temperature from 9 to 18 degrees C, while an optimum was reached at 15 degrees C in the cultivar 'Frida' that is selected under cool-environment conditions in Norway. Also, while saturated flowering response was obtained with 3 weeks of SD treatment at all temperatures in 'Frida', several plants of 'Florence' and 'Korona' failed to initiate flowers at 9 degrees C night temperature even with 5 weeks of SD. The effect of extended SD period was particularly pronounced in 'Florence'. The slow SD floral induction response of 'Florence' was associated with a 2 week delay of anthesis in subsequent long day (LD) conditions at 21 degrees C. Yield performance of the same cultivars during 2 years under field conditions at Nes Hedmark and in North Norway also demonstrated that the yield potential of 'Florence' was not realized under the climatic conditions prevailing at these locations. In both years the yields varied significantly among the cultivars,'Frida' having the highest yields followed by 'Korona', with 'Florence' far below. It is concluded that, in the Nordic environment, autumn (September) night temperatures are obviously suboptimal for yield performance of some June-bearing strawberry cultivars, and that this effect is mediated by autumn temperature effects on flower initiation responses. (C) 2008 Elsevier B.V. All rights reserved.
Sammendrag
Produksjonsklare planter er planter med ferdig utviklete blomsteranlegg, som kan drives og gi avling 2 " 3 mnd. etter planting. Gartnerhallen vil starte produksjon av slike planter av jordbær og bringebær. For å oppnå en tilfredsstillende kvalitet, må det skaffes ny kunnskap om vekstfysiologien hos jordbær og bringebær, for derigjennom å utvikle nye metoder og produksjonssystemer hos Gartnerhallens planteprodusenter. I 2006 ble det derfor etablert et 4-årig brukerstyrt prosjekt i regi av Gartnerhallen, med Bioforsk og UMB som samarbeidspartnere. Her vil vi presentere vekstfysiologiske resultater fra forsøk under kontrollerte klimaforhold med bringebærsorten "Glen Ample" (Sønsteby & Heide, 2008).
Sammendrag
A Canadian model that simulates the course of frost tolerance in winter wheat under continental climatic conditions was adopted and further developed for use in an oceanic climate. Experiments with two cultivars were conducted during two winters in Central Norway. All plants were hardened at the same location. After hardening, in mid November, they were distributed to three locations with contrasting winter climates. Plants were sampled several times during autumn and winter and tested for frost tolerance, expressed as LT50 (the temperature at which 50% of the plants were killed). Results from the experiment were used in parameterization and cross validation of the new model, called FROSTOL, which simulates LT50 on a daily basis from sowing onwards. Frost tolerance increases by hardening and decreases by dehardening and stress, the latter caused by either low temperatures, or by conditions where the soil is largely unfrozen and simultaneously covered with snow. The functional relationships of the model are all driven by soil temperature at 2 cut depth. One of them is in addition affected by snow cover depth, and two of them are conditioned by stage of vernalization. Altogether five coefficients allotted to four of the functional relationships produced a good agreement (R-2 = 0.84) between measured and modelled values of LT50. A cross validation of the model indicated that the parameters were satisfactorily insensitive to variation in winter weather. (c) 2007 Elsevier B.V. All rights reserved.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
The apple cultivar `Elstar" is the latest is the latest commercial maturing cultivar in Norway of high fruit quality when properly managed. In May 2006 a four years experiment with four different crop loads (2-4-6-8 flowers/fruitlets per TCSA cm2) were established at two stages (first bloom open and 20 mm fruitlets diameter) and compared to unthinned. Preliminary results from the two first seasons are presented. Fruit growth determination was conducted on individual fruits on each treatment during the season. Thinning at bloom to different crop levels gave a significant lower fruit set than thinning at the fruitlets stages to the same levels the first year. However, the fruit weight and the soluble solid contents were significant larger and ground colour improved when bloom thinning. The final fruit numbers at harvested was less than the amount established at bloom and fruitlets. There were significant differences between the different treatments in final fruits per TCSA and fruit set which reflected the different crop levels. Fruit weight and soluble solid contents were largest with lowest crop load and decreased with increasing crop levels. There was a strong crop load effect from the year before on the amounts of return bloom per tree. The trees thinned at bloom had significant more flower clusters than thinned at the fruitlet stage of 20 mm. The untreated, control trees had the lowest amount of flower clusters. The amount of return bloom declined with increasing crop load on the trees. The second year yield and fruit weight were larger when thinned at bloom. The highest crop load the second year was when thinned at bloom to the levels of 2 and 4 apples per TCSA the year before. The trees with the highest crop load the last year managed to give only a small crop. The fruit quality was in general high for all treatments.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Fruktdyrking er en langsiktig produksjon med store etableringskostnader. Forståelig nok har ingen dyrker lyst til å satse på ukjente sorter som det er usikkert om vil bli godt mottatt av omsetning og forbruker. Norsk kjernefruktproduksjon har derfor hatt lite fornying i sortimentet de siste årene. Et nytt prosjekt skal forsøke å rette opp på dette. Prosjektet er et samarbeide mellom fruktdyrkere, omsetningen, forsøksringene og forskningen.
Sammendrag
Den nye normen er 1,4 kg fosfor pr. daa til 400 kg korn, og innebærer en reduksjon på 0,6 kg i forhold til tidligere norm. I tillegg anbefales det å ikke gi fosfor ved P-AL over 15. Justering av gjødsling ved P-AL under 15 blir som før, men systemet er under revidering. Grunnlaget for den nye normen er prinsippet om balansegjødsling.