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.
2009
Sammendrag
The effects of timing of nitrogen (N) fertilization relative to the beginning of a 4-week floral-inducing short-clay (SD) period have been studied in 'Korona' strawberry plants under controlled environment conditions. Groups Of low fertility plants were fertilized with 100 ml of calcium nitrate solution for 3 days a week for a period of 3 weeks starting at various times before and at the beginning of the SD period, as well as at different times during the SD period. All plants, including SD and long day (LD) control plants, received a weekly fertilization with a low concentration complete fertilizer Solution throughout the experiment. Leaf at-ea. fresh and dry matter increments of leaves, crowns and roots, as well as leaf chlorophyll concentration (SPAD Values) were monitored during the experimental period. A general enhancement of growth took place at all times of N fertilization. This was paralleled by an increase in leaf chlorophyll concentration, indicating that the control plants were in a mild state of N deficiency. When N fertilization was started 2 weeks before beginning of the SD period, flowering was delayed by 7 days, and this was gradually changed to an advancement of 8 days when the same treatment was started 3 weeks after the first SD. The amount of flowering was generally increased by N fertilization although the effect varied greatly with the time of N application. The greatest flowering enhancement Occurred when N fertilization started I week after the first SD when the number of flowering crowns and the number of inflorescences per plant were more than doubled compared with the SD control, while fertilization 2 weeks before SD had no significant effect on these parameters. Importantly, the total number of crowns per plant was not affected by N fertilization at any time, indicating that enhancement of flowering was not due to an increase in potential inflorescence sites. No flowering took place in the control plants in LD. Possible physiological mechanisms involved and practical applications of the findings are discussed. (C) 2009 Elsevier B.V. All rights reserved.
Forfattere
Anita SønstebySammendrag
Det er ikke registrert sammendrag
Forfattere
Anita SønstebySammendrag
Det er ikke registrert sammendrag
Forfattere
Anita SønstebySammendrag
Månedsjordbær er remonterende typer av markjordbær (Fragaria vesca) som stammer fra planter som ble funnet i de franske Alpene for ca 350 år siden. I motsetning til vanlige markjordbær, som er kortdags-planter og heller ikke danner blomster ved temperaturer over ca 15 ºC, er månedsjordbær langdagsplanter med stor toleranse for høg temperatur og blomstrer rikt i lange dager ved 27 ºC. Dette er de samme blomstrings-reaksjonene som vi finner hos remonterende sorter av hagejordbær.
Sammendrag
Høstgjødsling av jordbær er relativt lite brukt hos oss. Stort sett får plantene passe seg selv etter at høstesesongen er over. Nylig utførte forsøk i kontrollert klima viste imidlertid at nitrogengjødsling idet blomsterdanningen innledes, like etter start av kort dag, kan forsterke blomsterdanningen. Derimot flrte N-gjødsling like før start av kort dag til forsinket blomstring. dette har aktualisert spørsmålet om presisjonsgjødsling av jordbær om høsten.
Forfattere
Anita SønstebySammendrag
Det er ikke registrert sammendrag
Sammendrag
Det vert stilt mange krav til nye jordbærsortar. Dei viktigaste er avling, smak, bærstorleik, resistens mot skadegjerarar og modningstid. Jordbærsesongen er svært kort, og vi treng både betre tidlege og seine sortar. I tillegg til dei vanlege sortane, vert interessante sortar med svært lang blomstring- og haustetid prøvde.
Sammendrag
In the Nordic strawberry industry only single-cropping cultivars are used. Several everbearing cultivars have been tried, but neither yield nor quality has been satisfactory. In 2005, new everbearing cultivars were collected and an experiment was established in a polyethylene tunnel. Yield and runnering capacity were recorded in two seasons. The cultivars were the English 'Flamenco' and 'Everest', the Dutch 'Elan' and the Norwegian 'Rita', 'Rondo', 'Ridder' and 'Rosa'. Plug plants were planted in double rows on low ridges mulched with plastic at a plant density equivalent to 50,000 plants per ha. A block design with 20 plants per plot and four replicates was used. The field was harvested two to three times a week during the whole season from June until the beginning of October in both years. Berry size was recorded at all harvests while taste and general performance were evaluated using a scale 1-9. In the first year, the everbearing cultivars had significantly higher yield than the single-cropping cultivars due to more inflorescences, but this was levelled out the second year. While the cropping season of the single-cropping cultivars is only about four weeks, the everbearing cultivars were picked from late June until beginning of October, in both years. The highest yields were obtained by 'Everest' (729 and 844 g) followed by 'Rita' and 'Ridder'. The cultivars 'Elan' and 'Rondo' scored highest both in taste and general performance. 'Everest' also performed well, but flavour was not acceptable.
Sammendrag
Techniques for the production of raspberry long canes with high yield potential were studied on a research station and in two commercial nurseries in South Norway. Potted 'Glen Ample' plants were grown in the open and in polyethylene greenhouses during two seasons in order to optimize Cultural practices. Dates of propagation and transfer to the production sites were varied. Following cold storage from December to early June, the canes were tipped (cut) at 160 cm height and grown in open plastic tunnels in the fruiting season for the evaluation of growth and yield performance. Remarkable berry yields of 1.5-3.8 kg per plant (cane) were regularly achieved. When grown in the open, later starts than June 1 (June 15 and July 1) successively reduced yields. On the other hand, an earlier start involves risks of growth cessation due to low spring temperature. When grown in greenhouses, high yields were still possible when plants were transferred from propagation conditions as late as July 1, although optimal yields of nearly 4 kg per plant were obtained with transfer on June 15. In a year with unusually high summer temperatures, the yields of canes produced in the open and in greenhouses did not vary significantly, whereas in the second year with normal summer temperatures, canes produced in greenhouses consistently out-yielded those produced in the open by about I kg per cane. Regression analyses revealed that high yields were associated with fruiting cane architecture traits such as cane height, number and length of laterals, and a low proportion of dormant buds. The single most important component was lateral length which alone accounted for 82% of the yield variation. Since lateral lengths increased from the shoot tip towards the base, cane heights in excess of 2 m are required for the attainment of top yields as the uppermost nodes with short and low-yielding laterals then can be eliminated by tipping. (C) 2009 Elsevier B.V. All rights reserved.
Forfattere
Anita SønstebySammendrag
Resultater og erfaringer med forsøk med produksjon av langskudd av bringebær, med vektlegging på klimapåvirkninger for vekst og blomsterdanning.