Unni Myrheim Roos

Avdelingsingeniør

(+47) 406 22 636
unni.myrheim.roos@nibio.no

Sted
Apelsvoll

Besøksadresse
Nylinna 226, 2849 Kapp

Sammendrag

Effects of annual versus biennial cropping with varying shoot densities on plant structure, berry yield and quality were studied in ‘Glen Ample’ raspberry over a period of four seasons (two cropping years). In the vegetative phase, primocane height and internode length were larger in the annual than in the biennial cropping system. These parameters as well as Botrytis infestation increased with increasing shoot density. In both cropping years, berry yields per unit area were about 20% higher in the biennial cropping system, whereas yields per shoot were not significantly different in the two systems. In both cropping systems, yields per shoot strongly declined with increasing shoot density, while yields per metre row increased slightly. Regardless of cropping system, yields per metre row did not increase with increasing shoot density beyond eight shoots per metre. The concentrations of dry matter, soluble solids, titratable acidity and ascorbic acid as well as the intensity of juice colour all declined with increasing shoot density. We conclude that under controlled shoot density conditions, there is little scope for biennial yield increases that fully compensates for the lost crops every second year. However, the system greatly facilitates berry harvest and eases plant disease pressure.

Sammendrag

As part of an overall assessment of the commercial suitability of strawberry cultivars for the Nordic environment, we studied 13 diverse cultivars in an experimental field in South East Norway. Early-maturing cultivars were characterized by early initiation of floral primordia and early flowering and fruit maturation. High temperatures in July and early August delayed floral initiation in the early cultivars, resulting in more synchronous initiation of early and late cultivars. The recent Norwegian cultivar ‘Nobel’, which has an everbearing parent, differed from the other cultivars by early initiation also at elevated summer temperature. Inadequate yield and berry size were identified as important causes for outdating of older cultivars, such as ‘Senga Sengana’ and ‘Glima’. Overall, the high-yielding and large-fruited ‘Sonata’ was judged as the best fresh consumption cultivar in Norway, and market trends indicate that it will continue to expand its market share at the expense of ‘Korona’, mainly because of inadequate fruit firmness and shelf life of the latter. Adequate yields and berry quality justify the use of the late maturing ‘Florence’ for prolongation of the fresh market season. The results are discussed together with practical experiences and market preferences in an attempt to provide overall cultivar recommendations for Norway.

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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.

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.

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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.

Sammendrag

Det er en vanlig oppfatning blant bærdyrkere at relativt lav høst-temperatur er gunstig for rik blomsterdanning hos jordbær og bringebær. I ei tid med klimaendringer, er det derfor mange som spør om hvordan de milde høstene vi har hatt i det siste, påvirker blomstring og avling. Vi har i de seinere åra studert blomstring hos arter og sorter av jordbær og bringebær under kontrollerte klimaforhold, og kan nå langt på vei forklare fysiologiske særtrekk for blomstringen hos disse artene, og derigjennom peke på fordeler og begrensninger for dyrkingen under endrede temperaturforhold. Hovedkonklusjonen blir, at mens mildere høster vil være en fordel for blomsterdanningen hos våre vanlige jordbærsorter, og for høstbærende bringebær, vil dette virke negativt og føre til seinere blomsterdanning hos to-årige bringebærsorter.

Project image
Innovative løsninger for økt lønnsomhet i grøntnæringa - TEKNOBÆR


De to største utfordringene norsk grøntnæring står ovenfor, er høye arbeidskostnader og stabilt høye avlinger av god kvalitet. Det skjer en rask teknologisk utvikling i og rundt landbruket. Bruk av avansert teknologi, inkludert robotisering til for eksempel behovsprøvd gjødsling, vanning og plantevern og ved innhøsting er ikke lengre framtiden, det er på full fart inn i internasjonalt landbruk. Hagebruksnæringen har arbeidsintensive produksjoner som har sterkt behov for å finne innovative løsninger på de høye arbeidskostnadene. Mer ekstremvær og utfordringer med resistens hos plantepatogene sopper og skadedyr mot kjemiske plantevernmidler gjør at norsk grøntproduksjon i framtida vil foregå med vær-vern, ved dyrking under et dekke av plast. I land som England, Frankrike, Nederland og Spania foregår i dag mer enn 90% av bærproduksjonen i plasttunneler. Bruk av plasttunneler gir bedre plantevekst, høyere avlinger og mindre problemer med viktige skadegjørere. Avlingen per arealenhet kan økes med 50 til 100%. Men det er mange utfordringer som må løses: næringsforsyningen må bli mer presis, plantevernstrategiene må tilpasses, kvaliteten på plantematerialet må forbedres, etc. I plasttunneler kan planter dyrkes i bakken eller på opphøyde renner, i jord eller i substrat. Plantene kan ‘designes’ til produksjonssystemet og overvintres på kjølelager, slik at produksjonen kan programmeres og sesongen utvides. En slik semi-kontrollert produksjon vil gi flere muligheter til å effektivisere arbeidsoperasjoner og gjøre produksjonen mer miljøvennlig. Satsingen vil gi økt kunnskap/kompetanse i NIBIO og bidra til å gjøre instituttet nasjonalt ledende innen forskning på tekniske løsninger i landbruket.

Aktiv Sist oppdatert: 21.11.2017
Slutt: des 2020
Start: jan 2017