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.
2018
Abstract
No abstract has been registered
Abstract
Increasing abundance of Juncus effusus (soft rush) and Juncus conglomeratus (compact rush) in pastures and meadows in western Norway has caused reductions in forage yield and quality in recent decades. Understanding plant development and regrowth following cutting is essential in devising cost-effective means to control rushes. In a field experiment in western Norway, we investigated development of above- and below-ground fractions of rush from seedlings to three-year-old plants, including the impact on vigour of disturbing growth by different cutting frequencies during the period 2009–2012. Each year, the plants were exposed to one or two annual cuts or left untreated and five destructive samplings were performed from March to early December. Juncus effusus showed significantly more vigorous growth than Juncus conglomeratus in the last two years of the study period. The above-ground:below-ground biomass ratio of both species increased mainly in spring and early summer and was reduced in late summer and autumn. Removal of aerial shoots also reduced the below-ground fraction of both species. One annual cut in July effectively reduced biomass production in both species by 30–82%, which was only a slightly smaller reduction than with two annual cuts, in June and August. Mechanical control measures such as cutting can thus effectively reduce rush vigour when performed late in the growing season.
Abstract
Viral diseases (a biotic stress) and salinity (an abiotic stress) have been/are the two major constraints for sustainable development of the world’s agricultural production including potato. Crops grown in field are often exposed simultaneously to abiotic and biotic stress, and responses of plants to co-stress by two or more factors may differ from those to each of the multiple stresses. Using in vitro cultures, we demonstrated that virus infection (singly and in combination) or salt, and co-stress by virus infection (singly and in combination) and salt significantly reduced growth and microtuber production, and caused severely oxidative cell damage determined by levels of O2·− and methane dicarboxylic aldehyde, and H2O2 localization in situ. Alterations in physiological metabolism by increasing total soluble sugar and free proline, and by decreasing chlorophyll content are responses of potato plantlets to virus infection (singly and in combination) or salt stress and co-stress by virus infection (singly and in combination) and salt. Oxidative cell damage and reduced chlorophyll content caused by virus and/or salt are believed to be responsible for the reduced growth, eventually resulting in decreased tuber yield. Results reported here would help us to better understand possible mechanism of reduced tuber yield by virus infection and/or salt stress.
Authors
Brian Titus Kendrick Brown Inge Stupak Helja-Sisko Helmisaari Viktor Bruckman Alexander Evans Elena Vanguelova Nicholas Clarke Iveta Varnagiryte-Kabasinskiene Kestutis ArmolaitisAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Björn RingselleAbstract
No abstract has been registered
Authors
Andreas Treu Katrin Zimmer Christian Brischke Erik Larnøy Lone Ross Foued Aloui Simon M Cragg Per Otto Flæte Miha Humar Mats Westin Luisa M. S. Borges John WilliamsAbstract
No abstract has been registered
Authors
Mekjell MelandAbstract
No abstract has been registered
Authors
Jarle W. Bjerke Ellen Elverland Laura Jaakola Leidulf Lund Bogdan Zagajewski Zbigniew Bochenek Andrzej Kłos Hans TømmervikAbstract
Climate change-induced snow thaw and subsequent accumulation of ice on the ground is a potential, major threat to snow-dominated ecosystems. While impacts of ground-ice on arctic wildlife are well explored, the impacts on tundra vegetation is far from understood. We therefore tested the vulnerability of two high-arctic plants, the prostrate shrub Salix polaris and the graminoid Luzula confusa, to ice encasement for 60 days under full environmental control. Both species were tolerant, showing only minor negative responses to the treatment. Subsequent exposure to simulated late spring frost increased the amount of damaged tissue, particularly in S. polaris, compared to the pre-frost situation. Wilting shoot tips of S. polaris increased nearly tenfold, while the proportion of wilted leaves of L. confusa increased by 15%. During recovery, damaged plants of S. polaris responded by extensive compensatory growth of new leaves that were much smaller than leaves of non-damaged shoots. The results suggest that S. polaris and L. confusa are rather tolerant to arctic winter-spring climate change, and this may be part of the reason for their wide distribution range and abundance in the Arctic.
Authors
Jens Peter Skovsgaard Jacob Johan Mohr Markmann Giulia Attocchi Bruce TalbotAbstract
The objective of this study was to establish an operational model of productive work time per tree (work efficiency) for high-pruning of young European beech and pedunculate oak depending on tree species, pruning height, branch characteristics, pole saw type and operator. The final model included all of these independent variables with branch characteristics specified in terms of number of live branches and cross-sectional area of the thickest branch at the cut. Work time increased with increasing values of each of the three numeric variables. For a given pruning height the size of the largest branch was for all practical purposes more influential than the number of live branches. Beech took 28% longer to prune than oak. The German Ergo-Schnitt saw was 21% slower than the Japanese Silky Hayauchi saw. The variation in worker performance within our study was larger than that attributed to tree species and pruning equipment.