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.
2017
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No abstract has been registered
Abstract
Area-efficient constructed systems for stormwater management and bioretention may involve large fluc-tuations in subsurface water levels. Such fluctuations challenge vegetation by forcing roots to exploredeeper layers to access water during dry periods. In a controlled experiment, we studied growth pat-terns and the ability of Phragmites australis roots to track subsurface water level fluctuations of differingamplitude and frequency in substrates with contrasting water-holding capacity. We found that P. aus-tralis was able to adjust its rooting pattern to considerable subsurface water level fluctuations (to wellbelow 120 cm), but that substrate characteristics can restrict its ability to adjust to larger fluctuations.Fluctuation amplitude was the driving factor for plant growth and biomass allocation responses, whilesubstrate characteristics and fluctuation frequency were less important. When not exposed to large waterlevel fluctuations, P. australis grew larger shoots and only explored intermediate rooting depths. Therewas a negative relationship between root and rhizome biomass, showing a resource-based trade-off andshort-term costs of adjusting rooting patterns to large water level fluctuations. These results indicatethat P. australis is suited for systems with considerable subsurface water fluctuations, but constraints onits flexibility need to be investigated.
Authors
Inger Sundheim FløistadAbstract
No abstract has been registered
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No abstract has been registered
Authors
M. Fotiric Aksic Vera Rakonjac Radosav Cerovic D. Nikolic Slavica Colic Mekjell MelandAbstract
Flowering is one of the most important factors in plant fertility. Fruit set in fruits is directly influenced by the beginning, sequence, flow, duration and abundance of flowering. The objective of this study was to evaluate the variability of flowering in 41 ‘Oblačinska’ sour cherry (Prunus cerasus L.) clones, and to recommend earlyflowering genotypes for growing in warmer locations where late spring frosts are rare, and some late-flowering clones for sites more susceptible for spring frost. Results from the three years period (2004-06), showed that ‘Oblačinska’ sour cherry clones flowered in a fixed sequence each year. Average for clone VII/2N, which flowered the earliest, was April 8 and petal fall took place by April 21, whereas clone III/1 bloomed last on April 14 and petal fall took place on April 25. Statistical analysis showed that almost all sub-phases of flowering were under the significant influence of both ecological and genetic factors. Besides, ecologic factors had the highest impact to the variability of beginning of flowering (79.8%), full bloom (76.8%), petal fall (80.2%) and duration of flowering (85.56%). Clones III/1, III/13, V/6 and V/2 were considered as late flowering, whereas clones VII/2N, VI/27, VI/28 and IX/P were early flowering, taking place five days earlier then previous group.
Authors
Synnøve Rivedal Samson Øpstad Sverre Heggset Trond Børresen Torbjørn Haukås Sissel Hansen Peter Dörsch Johannes DeelstraAbstract
No abstract has been registered
Authors
Synnøve Rivedal Samson Øpstad Sverre Heggset Sissel Hansen Trond Børresen Torbjørn Haukås Johannes Deelstra Peter DörschAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Different sowing methods and sowing rates were evaluated in organic seed production of timothy (two trials), meadow fescue (two trials) and red clover (one trial) in Southeast Norway, during 2010–2013. The plan included: (1) broadcast sowing of grass/clover, cover crop sown at 12 cm row distance; (2) sowing of cover and seed crop in crossed rows, both at 12 cm row distance; and (3) sowing of cover crop and seed crop in every other row. The three sowing rates were 5, 10 and 15 kg ha−1 in timothy and meadow fescue and 3, 6 and 9 kg ha−1 in red clover. On average for sowing rates and all trials with timothy, meadow fescue and red clover, first year’s seed yields were 5–6%, 20–25% and 19–25% higher on plots sown with cover crop and seed crop in every other row than on plots where seed crop had been broadcast or sown perpendicularly to the cover crop. The different sowing methods had no effect on weed coverage or weed contamination in the cleaned seed. Increasing sowing rate usually had a negative influence on seed yield, while weed coverage/contamination was not significantly affected. It is concluded that organic seed crops should be established with cover crop and seed crop in every other row at a low sowing rate. However, in an organic production system, even this favorable method will not always be sufficient to meet the requirement for seed crop purity.
Abstract
No abstract has been registered