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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.

2018

Til dokument

Sammendrag

The aim of the investigation was to assess and compare the environmental limits for growth cessation and floralinitiation in a range of new and established biennial-fruiting red raspberry (Rubus idaeus L.) cultivars of diverseorigin under phytotron and field conditions. The results confirmed that growth cessation and floral initiation inbiennial-fruiting red raspberry are jointly controlled by the interaction of low temperature and short days (SD).When transferred from non-inductive high temperature and long day (LD) conditions to naturally decreasingautumn daylengths at varying phytotron temperatures on 18 August, growth immediately levelled off and ceasedcompletely within 2 weeks in all cultivars at 9 °C. Serial dissections of lateral buds revealed that floral initiationsimultaneously took place. At 15 °C on the other hand, the plants continued growing and remained vegetativeuntil around 15 September when the daylength had decreased to approximately 13 h. The change to 9 °C resultedin an immediate but short-lasting floral induction response that did not bring about initiation in buds situatednear the base of the canes, as was the case at 15 °C. At 18 °C, marginal floral induction took place only in thecultivars ‘Glen Ample’, ‘Balder’ and ‘Vene’, even at photoperiods down to 10 h, whereas at 21 °C, all cultivarsgrew vegetatively regardless of daylength conditions. However, exceptions were some plants of ‘Vene’ and‘Anitra’ that initiated terminal flowers at 18 and 21 °C and flowered directly without chilling (so-called tipflowering). Although some cultivars of Northern origin ceased growing and initiated floral primordia somewhatearlier (at longer photoperiods) than those of more southerly origin, the differences were relatively minor andnot consistent (no latitudinal cline). Results obtained in the field under decreasing autumn temperature anddaylength conditions agreed closely with the results in the phytotron. We therefore conclude that results ob-tained with raspberry in properly controlled daylight phytotron experiments are generally applicable to fieldconditions.

Til dokument

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.