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.
2019
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Flowering performance and phenology of six new pear cultivars of Nordic origin were examined during a 12 year period. The seasonal timing of shoot growth and flower initiation were monitored in three years. The morphological floral stages of the flower bud formation process were examined for the cultivar ‘Celina’. Seven floral stages were identified and described. The date of full bloom varied between years as a function of the currently accumulated heat sum in early spring. Still, the earliness ranking of the cultivars was consistent across years for both flower initiation and blooming. The cultivars ‘Anna’ and ‘Ingeborg’ consistently initiated floral primordia 2–3 weeks earlier than ‘Celina’, ‘Clara Frijs’, ‘Fritjof’ and ‘Kristina’, and this was accompanied with 4–5 days earlier blooming in the following spring. The early flower initiation cultivars ‘Anna’ and ‘Ingeborg’ also had richer flowering than the late-blooming cultivars. ‘Fritjof’ was identified as a suitable pollinator for ‘Celina’ in the Nordic climate. Comparison of the flowering phenology of pear and apple cultivars showed that while the pears, on average, flowered a week ahead of the apples, they initiated flower primordia almost two weeks later, thus rendering the intervening period approximately three weeks longer in pear than in apple
Sammendrag
BACKGROUND: There is a search for raspberry cultivars with high sensory quality. The best way to determine sensory quality is by descriptive analysis. To perform sensory analysis by a trained panel is, however, not always feasible. Therefore, there is a need for instrumental measurements that correlate with sensory attributes. OBJECTIVE: To characterize eight genotypes of raspberry (Rubus idaeus L.) and to correlate sensory attributes with instrumentally determined quality. METHODS: Raspberry fruits were analysed by descriptive sensory analysis and by instrumental measurements, i.e. colour, total monomeric anthocyanins, soluble solids (SS), pH, titratable acidity (TA) and volatile compounds. The relationships between sensory attributes and instrumentally measured quality were determined by partial least square regression and by univariate correlation analysis. RESULTS: Sour and green odours/flavours versus chemical and cloying odours/flavours described most of the sensory variation of the raspberry genotypes. TA correlated with acidic taste, astringency and flavour intensity. SS/TA was positively correlated with sour flavour and sweet taste and negatively correlated with acidic taste and astringency. C6-aldehydes and (Z)-3-hexen-1-ol correlated positively with green flavour. _-ionone and _-ionone correlated with flower odour and flavour, respectively. CONCLUSIONS: Eight raspberry genotypes were characterized. Important sensory attributes could be predicted by instrumental measurements.
Sammendrag
We grew young sweet cherry (Prunus avium L.) trees under controlled temperature and natural summer daylight conditions in order to study the control of flowering of the species. Two experiments with the cultivars ‘Lapins’ and ‘Van’, were conducted and compared with field results with the same cultivars at Ås in southeast Norway (59° 40′N, 10° 50′E, 90 m a.s.l.). Shoot growth increased with increasing temperature in the 12–21 °C range, but ceased in late summer (August) regardless of temperature conditions. A marked drop in temperature always induced an immediate cessation of growth. Under field conditions at Ås, both growth cessation and floral initiation took place by about 1 August. Low temperature (12–15 °C) significantly enhanced flowering of both cultivars compared with 21 °C, which tended to depress flower bud formation during the summer but stimulated the subsequent flower differentiation process. These results concur with earlier regression analyses, which revealed a close positive correlation between historical records of sweet cherry yields over a 40-year period in farmer’s fields in the fjord districts of western Norway and previous year August-September temperature, and a negative correlation with previous year July temperature. Practical implications of the results are discussed and it is suggested that inadequate temperature control in rain-protected cultivation in plastic tunnels might have negative consequences for next year’s flowering and yield.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Kuldetolerante grønnsaker er planter som har utviklet beskyttelse av vekstpunktet mot kulde og frost. Selv med noen frostnetter er, fortsetter disse plantene å vokse når temperatur og lys om dagen, tillater det. Det gir unike muligheter til å utvide grønnsakssesongen, og gi en «skuldersesong» fra sensommer til tidlig vinter. Egnede planter står ute på feltet gjennom vinteren, for å gi produksjon tidlig neste vår. Fordelene med produksjon av kuldetolerante grønnsaker, er innføring av en ny «skuldersesong», redusert næringstap fra jorda, lite utfordringer med skadedyr, gi et større mangfold innen nyhøstete vintergrønnsaker til forbruker, øke verdigrunnlaget for dyrkere og øke regionale muligheter for sysselsetting. Det er utført vekstforsøk på tre utvalgte steder i landet med ulike årsvariasjoner, med hensyn til daglengde og temperatur. Grønnsakssorter ble valgt ut etter evne til å tolerere kulde i tillegg til rask utviklingstid. Mange av disse grønnsakene har en stor utfordring med stokkrenning, men løsningen ble sen såing, fra slutten av juli til begynnelsen av august. Det blir tidligere lave temperaturer i Nord-Norge og og til dels på Østlandet, slik at den optimale vekstperioden er noe kortere enn på Sørlandet. Det ble testet om forkultivering inne av småplanter for utsetting på felt, kunne bidra til å gi større planter før høsting. I våre forsøk etablerte de direktesådde grønnsakene seg raskest og fikk størst avling. Grønnsakene fikk også en mildere og søtere smak om de ble høstet etter en liten kuldeperiode.
Sammendrag
Green-sprouting potato seed tubers in light and elevated temperatures are vital for production in short-season climates. Using light-emitting diodes (LEDs) to inhibit sprout elongation during pre-sprouting may represent an energy-efficient alternative to traditional indoor light sources. Sprout growth inhibition and some photomorphogenic responses were therefore examined in potato cultivars exposed to LEDs of different wavelength maxima and irradiance rates. Red LED (660 nm) produced the strongest inhibition of sprout elongation at very low irradiances 10–100 nmol m−2 s−1, while far-red LED (735 nm) produced the strongest inhibition at higher irradiances. This inhibitory pattern was similar in all cultivars, although the degree of inhibition varied. The colour of sprouts and tuber skin remained etiolated under far-red LED, in contrast to LEDs between 380 and 660 nm which developed green colour intensity in an irradiance-dependent manner. Mixtures of red and far-red light, and pulses including red/far-red reversals did not produce stronger inhibition, except in some instances where total fluence was increased. Furthermore, green-sprouting under different LED colours did not seem to affect subsequent emergence and growth after planting. The current results suggest an involvement of multiple phytochromes in de-etiolation and sprout growth inhibition in seed potato tubers, which may be selectively utilised in LED-based green-sprouting in red and far-red wavelengths.
Forfattere
Francisco Javier Ancin Murguzur Gregory Taff Corine Davids Hans Tømmervik Jørgen A.B. Mølmann Marit JørgensenSammendrag
Ruminant fodder production in agricultural lands in latitudes above the Arctic Circle is constrained by short and hectic growing seasons with a 24-hour photoperiod and low growth temperatures. The use of remote sensing to measure crop production at high latitudes is hindered by intrinsic challenges, such as a low sun elevation angle and a coastal climate with high humidity, which influences the spectral signatures of the sampled vegetation. We used a portable spectrometer (ASD FieldSpec 3) to assess spectra of grass crops and found that when applying multivariate models to the hyperspectral datasets, results show significant predictability of yields (R2 > 0.55, root mean squared error (RMSE) < 180), even when captured under sub-optimal conditions. These results are consistent both in the full spectral range of the spectrometer (350–2500 nm) and in the 350–900 nm spectral range, which is a region more robust against air moisture. Sentinel-2A simulations resulted in moderately robust models that could be used in qualitative assessments of field productivity. In addition, simulation of the upcoming hyperspectral EnMap satellite bands showed its potential applicability to measure yields in northern latitudes both in the full spectral range of the satellite (420–2450 nm) with similar performance as the Sentinel-2A satellite and in the 420–900 nm range with a comparable reliability to the portable spectrometer. The combination of EnMap and Sentinel-2A to detect fields with low productivity and portable spectrometers to identify the fields or specific regions of fields with the lowest production can help optimize the management of fodder production in high latitudes.
Forfattere
Pia Heltoft Thomsen Trygve S. Aamlid Karin Juul Hesselsøe Karin Normann Bjarni Hannesson Kemeng XiaoSammendrag
Det er ikke registrert sammendrag
Forfattere
Mette Thomsen Trude Wicklund Rune Andreassen Peter Martin Hilde Halland Magnus Göransson Morten Rasmussen Olafur ReykdalSammendrag
Det er ikke registrert sammendrag