Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2019
Abstract
The presence of pollinators in orchards is crucial to obtain high fruit set and yields of fruits. Despite the fact that sour cherry cultivars are mainly autogamous, insect visits are still of great importance for their propagation. In order to attract and reward pollinators, flowers have to provide adequate nourishment to them. Besides nectar, bees gather pollen, which are a prerequisite for normal colony growth and development of their broods. ‘Oblačinska’ sour cherry (Prunus cerasus L.), an autochthonous cultivar, is the most highly planted cultivar in Serbian commercial orchards. Since the cultivar is actually a mixture of different clones, variability in numerous traits and, particularly, its yields has been reported. Since phenolic compounds are considered to be fundamental pollen chemicals, the aim of this study was to determine the phenolic compounds profile in pollen collected from 15 ‘Oblačinska’ sour cherry clones with varying productivity levels. Solid phase extraction (SPE), combined with ultra-high-performance liquid chromatography coupled with a diode array detector and a triple quadruple mass spectrometer (UHPLC DAD-MS/MS), was used to analyse the polyphenolic profile of pollen. Among 23 components quantified, rutin was the most abundant phenolic compound. It ranged from 98.49 (clone V/P) to 358.83 mg kg-1 (clone III/9) and was observed to contribute, on average, 56% of the total phenolic compounds in pollen as quantified in different ‘Oblačinska’ sour cherry clones. In addition to this compound, clones contained significant amounts of chlorogenic acid (12.92%), astragalin (8.19%), and hyperoside (5.59%) as well. Cluster analysis grouped pollen clones in four different clusters, which showed that clones III/9, IV/8, and V/P had unique phenolic profiles. Despite the significant differences among the studied clones, the contents of chlorogenic acid, rutin, naringin, hyperoside, astralgin, and phlorizin were distinguishable between the clusters.
Abstract
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Authors
Mekjell MelandAbstract
No abstract has been registered
Authors
Mekjell MelandAbstract
Sweet cherry production worldwide is grown in the open land. Production technique is more or less similar with scions grafted on dwarfing and semi-dwarfing rootstock and trees arranged in single rows. Sweet cherries can be grown in Norway in areas with suitable local climatic conditions up to 60°N. All orchards have high density planting systems and are rain covered. Rain-induced fruit cracking in cherries remains a problem at an international level. The most common systems in Norway are multibay high tunnel systems and retractable rain covers. Covered orchard tunnel systems offer not only the advantage of rain exclusion but also allow additional manipulation of the environment, tree growth and fruiting. In general, sweet cherry high tunnel production gives increased yields of larger fruit than in the open land, but investment costs are higher. This overview article describes results from different experiments about high tunnels sweet cherry production mainly conducted at Nibio Ullensvang, Norway during the last ten years.
Abstract
Cherries (Prunus avium L. and Prunus cerasus L.) are economically important fruit species in the temperate region. Both are entomophilous fruit species, thus need pollinators to give high yields. Since cherry’s flower is easy-to-reach, bees and other pollinators can smoothly collect nectar as a reward for doing transfer of pollen to receptive stigma. Nectar in cherry is usually attractive for insects, especially to honey bee (Apis melifera) who is the most common pollinator. Nectar is predominantly an aqueous solution of sugars, proteins, and free amino acids among which sugars are the most dominant. Trace amounts of lipids, organic acids, iridoid glycosides, minerals, vitamins, alkaloids, plant hormones, non-protein amino, terpenoids, glucosinolates, and cardenolides can be found in nectar too. Cherry flower may secrete nectar for 2–4 days and, depending on the cultivar, produces up to 10 mg nectar with sugar concentration from 28% to 55%. Detailed chemical analysis of cherry nectar described in this chapter is focused on sugar and phenolic profile in sour cherry. The most abounded sugars in cherry nectar was fructose, glucose, and sucrose, while arabinose, rhamnose, maltose, isomaltose, trehalose, gentiobiose, turanose, panose, melezitose, maltotriose, isomaltotriose, as well as the sugar alcohols glycerol, erythritol, arabitol, galactitol, and mannitol are present as minor constituents. Regarding polyphenolics, rutin was the most abundant phenolic compound followed by naringenin and chrysin. Cherry cultivars showed different chemical composition of nectar which implies that its content is cultivar dependent.
Abstract
Sweet cherry production worldwide is grown in the open land. Production technique is more or less similar with scions grafted on dwarfing and semi-dwarfing rootstock and trees arranged in single rows. Sweet cherries can be grown in Norway in areas with suitable local climatic conditions up to 60°N. All orchards have high-density planting systems and are rain covered. Rain-induced fruit cracking in cherries remains a problem at an international level. The most common systems in Norway are multibay high tunnel systems and retractable rain covers. Covered orchard tunnel systems offer not only the advantage of rain exclusion but also allow additional manipulation of the environment, tree growth and fruiting. In general, sweet cherry high tunnel production gives increased yields of larger fruit than in the open land, but investment costs are higher. One more advanced way of producing sweet cherries is to grow the trees in small pots in greenhouses. A greenhouse gives opportunity to control the temperature regime and in that way program the maturity of the fruits. Research is conducted to test different cultivars, rootstocks, training methods in high-density production systems (1 tree m-2) with different fertigation levels. Preliminary results show that the yield potential is much higher than in the open land with larger fruits. Challenges are to optimize the water and nutrition supply and adjust the temperatures to obtain large yields of high quality fruits during different periods of the season.
Abstract
No abstract has been registered
Abstract
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.
Abstract
No abstract has been registered