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.
2009
Authors
David Bredström Petrus Jönsson Mikael RönnqvistAbstract
A cost efficient use of harvesting resources is important in the forest industry. The main planning is made in an annual resource plan which is continuously revised. The harvesting operations are divided into harvesting and forwarding. The harvesting operation fells trees and put them in piles in the harvest areas. The forwarding operation collects piles and moves them to storage locations adjacent to forest roads. These operations are done by machines (harvesters, forwarders and harwarders) and these are operated by crews living in cities/villages which are within some maximum distance from the harvest areas. Machines, harvest teams and harvest areas have different characteristic and properties and it is difficult to come up with the best possible match throughout the year. The aim with the planning is to come up with a cost efficient plan The total cost is based on three parts; production cost, traveling cost and moving cost. The production cost is the cost for the harvesting and the forwarding. The traveling cost is the cost for driving back and forward (daily) to the harvest area from the home base. Moving cost is associated with moving the machines and equipment between harvest areas. The Forest Research Institute of Sweden has together with a number of Swedish forest companies developed a decision support platform for the planning. An important aspect is to come up with high quality plans within short computational time. A central part is an optimization model which integrates assignment of machines to harvest areas and scheduling of the harvest areas during the year for each machine. The problem is complex and we propose a two phase solution method where we first solve the assignment problem and in a second stage the scheduling. In order be able to control the scheduling also in phase 1, we have introduced an extra cost component which balances the geographical spread of the assignments in phase 1. We have tested the solution approach on a case study from one of the larger Swedish forest companies. This case study involves 46 machines and 968 harvest areas representing a log volume of 1,33 million cubic meters. We describe some numerical results and experiences from the development and tests.
Authors
Mensur Vegara Thor S. Larsen Hans Magnus Gjøen Anders Kiessling Roger K. Abrahamsen Ole Hofstad Lars Helge Frivold Bal Ram Singh Gunnar Klemetsdal Geir-Harald Strand Dag Ragnar Blystad Åsmund AsdalAbstract
The main objectives under this programme were: - To improve organising, content and quality of academic education and research in agriculture, veterinary medicine and forestry to meet with needs for qualified people in ongoing rebuilding after wars and to reach the general European level and standards. - Create functional and sustainable networks of regional institutions and professionals to support each other and cooperate for optimal use of limited available resources in the SEE region in a difficult rebuilding situation. The main activities were: - Research and development projects in the areas of animal sciences, crop and fodder production and use of GIS-methods in forestry and agriculture. - Support to development of staff and institutions in form of study stays, study material, covering of costs for laboratory analysis etc. related to M.Sc. and Ph.D. thesis work, guest lecturing and some equipment. - Support to reorientation of academic education in agriculture, forestry and veterinary medicine. - Support to regional networks, professional meetings, further development and use of the Programme web site and web-based teaching. The most important strategy in this Programme was to facilitate for institutional cooperation and network building between partners in the SEE area. Therefore a broad approach was chosen with a large number of partners (16) from all actual geographical areas in SEE - West Balkan - (Albania, Bosnia & Herzegovina, Croatia, Kosovo, Macedonia and Serbia & Montenegro) and representing most of the different ethnical groups in the region. The main intensions under the new programme is to improve the organisation, content and quality of academic education, research and support services in the faculties of agriculture, veterinary medicine and forestry in order to meet national needs in the ongoing reconstruction after the regional wars. Programme activities include activities that: ? Support and strengthen selected institutions in SEE/WB towards obtaining European professional levels and standards. ? Promote networking and scientific cooperation between the SEE/WB institutions. ? Promote networking and scientific cooperation between institutions in SEE/WB and in Norway.
Authors
Øystein Johnsen Harald Kvaalen Igor A. Yakovlev O.G. Dæhlen Carl Gunnar Fossdal Tore SkrøppaAbstract
No abstract has been registered
Authors
Steffen Adler Annette Veberg Dahl Håvard Steinshamn Anne Holter Vae Erling Thuen Torstein H. Garmo Søren Krogh-JensenAbstract
A continuous grazing experiment with three measurement periods, 3 weeks each, was conducted with 16 Norwegian Red dairy cows in mid lactation to compare milk quality when grazing red clover-grass (R) or botanical diverse pasture (D). The cows were offered either R or D from the start of grazing season in mid May until beginning of September 2008. Milk yield was measured and milk samples were collected in the last week in each period (end of June, beginning of August and end of August). Pasture type had no effect on milk yield and milk content of fat or protein. Cows grazing R had higher proportion of the fatty acids C18:0 (22.41 vs. 9.96, P<0.05) and C18:1t11 (0.58 vs. 0.44 g/100g FAME, P<0.05) and lower proportion of C16:0 (27.83 vs. 30.92, P<0.05) in their milk fat than the cows grazing D. The milk content of ?-tocopherol was higher in milk from R than D (3.01 vs. 2.64 µg/ml, P<0.05). The oxidative stability of the milk lipids were only minor affected by pasture type.
Authors
Dana Daniela Maria Soare Daniela Stefanescu Valentina Cotet Tore Krogstad Marianne Bechmann Florin Oancea Carmen Lupu Florentin ChitoranAbstract
No abstract has been registered
Abstract
Neozygites floridana is a fungus in the order Entomophthorales that is a natural enemy of several spider mite species including the two-spotted spider mite, Tetranychus urticae. When conditions are right, this fungus may cause epizootics in spider mite populations and kill high numbers of mites. The fungus is therefore promising for biological control of T. urticae in strawberry and can be used in combination with other pest management strategies. Our previous studies have shown that N. floridana is compatible with other biocontrol methods such as predatory mites. Phytoseiulus longipes fed on fungus-infected T. urticae laid equal number of eggs to those fed on healthy prey. This indicates that the fungus does not affect this predatory mite negatively. In a choice experiment (hosts with and without N. floridana), P. longipes fed indiscriminately irrespective of the presence of the fungus. The compatibility of biological control methods with pesticides is of great importance for an integrated pest management system to work well. Some acaricides and fungicides have the potential to affect both beneficial fungi and predatory mites and careful selection of pesticides that are not harmful to these beneficial organisms can promote their biocontrol potential. Our studies have shown that the fungicides captan, mancozeb, tolylfluanid, fenhexamid, cyprodinil + fludioxonil affect N. floridana in a way that may be detrimental to the biocontrol potential of this beneficial fungus in the field. Use of resistant varieties is also important in integrated pest management because pests are known to be more vulnerable to pathogens if they feed on poor or resistant plants and our studies on effects of host plants of spider mites confirms this.
Abstract
Neozygites floridana is a fungus in the order Entomophthorales that infects and kills the two-spotted spider mite, Tetranychus urticae. The fungus is therefore of interest in the biological control of T. urticae. To obtain information that might help in the use of this fungus under practical conditions in strawberries and cucumbers we have tried to answer the following questions in a series of studies: 1) When, and at what infection levels does N. floridana occur in T. urticae populations in field grown strawberries in Norway? 2) How does N. floridana survive harsh climatic conditions (i.e winter) in Norway? 3) Where do N. floridana infected T. urticae move and sporulate on a plant? 4) How can N. floridana be inoculated in augmentative microbial control of T. urticae? Results show that the N. floridana infection level varies considerably throughout a season. T. urticae killed by N. floridana was found to sporulate surprisingly early in the season (first observation March 18) and infection early in the season is important for a good control of T. urticae. N. floridana was observed to over-winter as hyphal bodies in hibernating T. urticae females throughout the winter. Cadavers with resting spores were found from October to the end of January only. Cadavers then probably disintegrated, and resting spores were left on leaves, soil, etc. In a bioassay where a Norwegian N. floridana isolate was tested for numbers and distance of spores thrown at three different temperatures relevant to Norwegian conditions (13o, 18o, 23o C), results show that the highest numbers of spores (1886 and 1733 per cadaver) were thrown at 13o and 18o compared to 23o C (1302 per cadaver). Spores were thrown at the same distance (up to about 6 mm) at all three temperatures. These results show that the fungus may be a promising agent at temperatures relevant for strawberry production in countries located in Northern areas. Our attempt to inoculate N. floridana artificially in a strawberry field and also in greenhouse cucumbers has not been successful yet, but we are working to improve the methods in a new project titled "BERRYSYS -A system approach to biocontrol in organic and integrated strawberry production".
Abstract
The vine weevil, Othiorynchus sulcatus, is a serious pest in strawberries and biological control methods are needed to combat this pest. Formulations of the insect pathogenic fungus Metarhizium anisopliae is registered for use against Otiorhynchus spp. in several countries but no fungal control agents are avilable for control of O. sulcatus in Norway. All developmental stages of Otiorhynchus spp. are susceptible to virulent insect pathogenic fungal species, but best control has been achieved against the larvae (Moorhouse et al. 1992). A number of studies have shown that M. anisopliae and Beauveria bassiana have good potential against Otiorhynchus spp. (Cross et al. 2001). In field grown strawberries, good control with Metarhizium has been reported when environmental conditions for the fungus are favourable (Oakley 1994). Temperatures in excess of 15oC are required for good control by most fungal isolates. Low temperature is therefore a major restricting factor for use of fungi outdoors (Gillespie et al. 1989, Soares et al. 1983). Isolates with low temperature optimums could therefore be well suited for field conditions in Northern Europe, where soil temperatures at the time when most larvae are found in the soil in autumn are 10-12oC. Norwegian M. anisopliae and B. bassiana isolates have shown promising results against O. sulcatus larvae at low temperatures in laboratory bioassays (Hjeljord & Klingen 2005). One of the Norwegian M. anisopliae isolates has also shown good competition with other soil fungi in laboratory experiments (Hjeljord & Meadow 2005). In addition to being cold tolerant, rhizosphere competence is important for fungal control agents that are used to control root feeding pests. "Rhizosphere competence" has been defined when considering biological control agents as "the ability of a microorganism, applied by seed treatment, to colonize the rhizosphere of developing roots" (Baker 1991). In this study we therefore aimed at testing the survival and rhizosphere competence of two different cold active Norwegian isolates (M. anisopliae isolate NCRI 250/02 and B. bassiana NCRI 12/96) in a semi field experiment in Norway. These were compared with the commercially avilable M. anisopliae isolate Ma43 originating from Austria (the isolate is also known to have many other names (Eilenberg 2008)). The study was conducted by estimating fungal concentrations in the bulk and rhizosphere soil surrounding the strawberry plant roots by counting colony forming unists (CFUs). The highest numbers of B. bassiana NCRI 12/96 CFUs were seen in the rhizosphere at 1.87x109 per liter soil 3 months after application. The highest numbers of M. anisopliae NCRI 250/02 CFUs were seen in the rhizosphere at 2.41x109 per liter soil 1 year after application. Numbers of CFUs for the M. ansiopliae Ma43 CFUs were generally lower than for the Norwegian isolates, but also for this isolate a higher fungal concentration was found in the rihzosphere soil than in the bulk soil.
Authors
Maria Björkman B. Båth P. Hambäck B. Rämert K. Thorup-KristensenAbstract
Intercropping has been shown to lead to reduced attacks from several pest insects, as for example the turnip root fly (Delia floralis). This study shows that the oviposition of D. floralis can be reduced further if intercropping is combined with a trap crop. Yield losses due to plant competition in the intercropping can be reduced by pruning the roots of the companion plant and by choosing a low competitive companion plant species.
Authors
Eva Birken Mekjell MelandAbstract
This paper describes briefly the phenomena of alternate bearing of European plums and point out that more detailed investigations about physiological factors, in particular plant hormones, involved in the flowering process are of great importance.