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.
2002
Authors
Cecilia Futsæther Nina Elisabeth Nagy Live Eikenes Anders Lønneborg Anders Johnsson Trond E. Singstad Ane V. VollsnesAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Toril Drabløs Eldhuset Arne SandnesAbstract
• Micro suction cups are useful for collecting soil solution at high spatial resolution, e.g. gradients in the rhizosphere. • Their success in the field depends on soil type and the soil water content. • Both inorganic ions, organic acids, and pH in the soil solution showed high variability through time. • Unexpectedly, the concentration of major cations and anions were higher in the rhizosphere than in the bulk soil. • Only four organic acids were detected with certainty, i.e. by use of retention times and spectra of known standards. • Low initial concentrations with subsequent microbial breakdown in the samples vials and analytical limitations of small volume samples are considered to be the main reasons for the small number of acids detected.
Authors
Ola FlatenAbstract
No abstract has been registered
Authors
Inger Sundheim FløistadAbstract
No abstract has been registered
Abstract
Cleaning of containers to counteract infection that might cause root dieback should remove old, adhering media and roots that may harbour pathogens. This study investigated seedling growth and the number of viable fungal propagules retained on the container cavity walls as a result of different container cleaning treatments: washing with cold water (ca 8C) only, or in addition with a bath temperature of 60, 70, 80 or 95C for 30 seconds.More fungal propagules were isolated from containers washed in cold water, than from the other treatments. The most frequently isolated fungi were Paecilomyces sp. and Penicillium sp., which are well known saprophytes. Bacteria and yeast did not seem to be affected by the washing.Electron microscopy studies of container cavity walls revealed many organic particles and fungal spores on the walls of coldwashed containers. Among other fungal spores there were visible chains of Paecilomyces spp. spores.Containers that were washed at 80C had some organic debris attached to the cavity walls, but no spores were visible. In used and unwashed containers fungal spores, hyphae and organic debris were found on the container cavity walls. Containers in which the major part of the seedlings previously had suffered from root dieback might have contained a considerable amount of inoculum before washing.Almost 60% of the seedlings grown in unwashed containers had dead or very stunted root systems, whereas about 10% of the seedlings in cold washed containers suffered from severe root dieback. Additional warm water treatment further reduced the root dieback of this group of containers. In unwashed containers in which healthy seedlings had been grown, about 4% seedlings and after cold washing no seedlings with root dieback were observed.The cold washing procedure had a positive effect on seedling height, but there was no additional effect of the warm water treatment. We conclude that cold pressurised washing alone does not provide adequate control of root dieback and that an additional warm water bath of at least 60C is recommended.
Abstract
The purpose of this study was to test the activity of gibberellins and auxins for induction of parthenocarpic fruit development in cloudberry, Rubus chamaemorus L., a dioecious, northern wild berry with potential for cultivation. Plant hormones were applied directly to open flowers, either dissolved in ethanol or as an aqueous spray. Of the tested gibberellins (GA1, GA3, GA4, dimethyl-GA4, GA5, GA9, GA19, GA20 and GA24) only GA1, GA3, GA4 and dimethyl-GA4 were active and induced fruit development comparable to development of pollinated fruits. Lack of activity of GA20 and GA9, the immediate precursors of GA1 and GA4, respectively, suggests that 3 b-hydroxylation of gibberellins can be inhibited in unpollinated flowers of cloudberry. Auxin treatments induced an initial fruit development, but did not result in ripe berries. Based on these results, use of transgenic methods to regulate gibberellin or/and auxin biosynthesis in carpels of cloudberry could be used to develop a parthenocarpic cloudberry.
Abstract
No abstract has been registered
Abstract
The Norwegian intensive monitoring programme of forest condition has recorded rainfall, throughfall and soil water data from 1986 at 16 forest plots. Using covariance analysis, this study has examined short term and episodic influences on soil water ionic concentration at three of the plots, and identified both seasonal and long-term temporal trends. Acidity has decreased in bulk precipitation and throughfall, and the concentrations of base cations in the organic soil horizon have increased. Nevertheless, there is evidence of continued acidification in the organic and mineral soil horizons, though of a small scale. The influence of sea salt and drought effects on soil water chemistry are examined, but found to be unimportant in causing acidification effects such as increased soil aluminium concentration.