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.
2006
Abstract
Resins and oils can easily evaporate during drying processes at high temperatures. The aim of this research was to investigate different drying methods such as oven-drying, vacuumdrying and freeze-drying of resin modified pine-sapwood samples to determine wood moisture content (MC) and weight percent gain (WPG). The results showed that freeze-drying is the slowest process. Vacuum drying of water impregnated samples takes approx. 7 times longer compared to oven-drying. The initial moisture content of wood before impregnation used in this research has only little influence on the WPG.
Authors
Andreas TreuAbstract
No abstract has been registered
Authors
Joha W. Grobbelaar Michael J. Wingfield P. Bloomer Halvor Solheim Brenda D. WingfieldAbstract
No abstract has been registered
Authors
Seppo NevalainenAbstract
No abstract has been registered
Abstract
Conventional farmers converting to organics have contributed to most of the rapid expansion of organic farming in recent years. The new organic farmers may differ from their more established colleagues, which may have implications for the development of the organic farming sector and its distinctiveness vis-a-vis conventional production and marketing practices. The aim of this study was to explore Norwegian organic dairy farmers' personal and farm production characteristics, farming goals, conversion motives, and attitudes to organic farming, grouped by year of conversion (three groups). A postal survey was undertaken among organic dairy farmers (n=161). The results show that the newcomers (converted in 2000 or later) were less educated than the early entrants (the so-called 'old guard') who converted in 1995 or earlier. The frequency of activities like vegetable growing and poultry farming among the old guard was high. The late-entry organic herds were fed with more concentrates and had a higher milk production intensity, showed a higher incidence of veterinary treatments and less frequent use of alternative medicine than the herds of the two earlier converting groups. For all groups of farmers, the highest ranked farming goals were sustainable and environment-friendly farming and the production of high-quality food. Late entrants more often mentioned goals related to profit and leisure time. On average, the most frequently mentioned motives for conversion were food quality and professional challenges. The old guard was more strongly motivated by food quality and soil fertility/pollution issues than the others, whereas financial reasons (organic payments included) were relatively more important among the newcomers. All groups held very favorable views about the environmental qualities of organic farming methods, albeit with different strengths of beliefs. Even though trends towards more pragmatic and business-oriented farming were found, the majority of the newcomers were fairly committed.
Abstract
The aim of this study was to compare two methods for non-destructive strength testing of wood by the use of dynamic modulus of elasticity (MOEdyn). The two methods are based on resonant vibration excitation and ultrasonic pulse excitation. Sound Pinus sylvestris L. sapwood samples treated with two copper-containing wood preservatives and two chitosan solutions were evaluated at two moisture levels. There was a significant correlation between the measurements given by the two MOEdyn test devices. An analysis of variance showed significant differences between the different treatments and between different moisture levels. Potential use of the non-destructive MOEdyn methods in durability testing is discussed.
Abstract
According to previous studies, short day (SD) treatment may increase frost hardiness in Picea abies (L.) Karst. seedlings during shoot elongation the next year. The purpose of this study was to examine how timing of the SD treatment affects spring frost hardiness. The following four treatments were applied in the first growth period: natural photoperiod (Nat), or SD treatment (8/16 h, day/night) either from 14-28 July (SD1), 28 July-11 August (SD2), or 11 20 August (SD3). After 125 days in the cold store (October-January), the seedlings were transferred to forcing conditions (20-25oC, 24 h photoperiod) followed by freezing tests at 3, -5, -7 and 9oC when most seedlings had reached bud break stage 7 (Krutzsch index). Seedling height measurements and analyses of carbohydrate status, nitrogen concentration and dry weight of needles after cold storage were done to examine the treatments` impact on seedling quality. SD treatment reduced visual freezing injury to current- and first-year shoots. Mortality occurred at –7 and –9oC and was significantly higher in treatments Nat and SD1 (43% in both) than in the SD2 (23%) and SD3 (15%) treatments. Seedlings from the late SD treatments also showed better height growth and developed more shoots from dormant buds after freezing to –3 and –5oC. Collectively, these findings demonstrate the importance of proper timing of the SD treatment in relation to the seedlings’ natural growth rhythm.
Abstract
No abstract has been registered
Abstract
Results from a literature review on pinewood ecology, silviculture, genetics, aspects of history and forest resources of Scots pine (Pinus sylvestris L.) in western Norway are presented. The pinewoods cover 40 per cent of the forested land, 0.31 million ha. During the last 75 years, the area has increased by 17 per cent and the growing stock has risen from 10 to 34 million m3. The impact of man in previous times was very marked, and has had a significant influence on the present forest conditions. The pronounced climatic gradients mixed with the topographic variation - from the coastal plains via the fjord systems to the high mountains - is reflected in rather steep gradients in the pine forest vegetation. Various floristic elements can be distinguished, from oceanic via the suboceanic in the outer islands to the thermophytic, boreonemoral and boreal elements in the inner fjord districts and valleys. The introduction of spruce (Picea spp.) plantations on 10-15 per cent of former native pine forests has not negatively affected the bird fauna at the landscape scale. Although not particular species rich, the pine forests harbour species usually not found in other forest types. So far, most work in the field of silviculture and forest ecology in the pinewoods of West Norway has been in the form of case studies. Implications of the results for forestry in the region are briefly discussed.
Authors
May Sæthre Arne Hermansen Ragnhild NærstadAbstract
The western flower thrips, Frankliniella occidentalis (Pergande), is a highly polyphagous species with a host range including over 250 species of herbaceous and woody plants belonging to 62 families. F. occidentalis originates in western USA but has spread, since 1970, into many countries in Asia, Africa, Central and South America, Europe and Oceania. In southern regions of Europe the pest is found outdoors attacking the flowers of a number of host plants. In northern European countries it is a pest mainly in protected crops (i.e. glasshouses) attacking a number of ornamentals and vegetables. F. occidentalis is a vector of Tomato spotted wilt virus (TSWV) and several other viruses. Both these organisms are regulated as quarantine pests in the EPPO region (European and Mediterranean Plant Protection Organization). The first report of F. occidentalis in Norway was in 1986 and it spread very quickly within greenhouse environments. In 1987 the species was added to the A-list (quarantine pests with zero-tolerance on import to Norway) and a comprehensive spraying program to eradicate the introduced pest and stop further spread was developed. The thrips, however, continued to spread and in 1991 about 40% of all greenhouses in Norway were infested with F. occidentalis. A plan of action (Trips-aksjonen) to combat and eradicate F. occidentalis from Norway was executed in 1991. In spite of extensive efforts by growers and authorities they did not succeed in eradicating or stopping further spread of F. occidentalis. In 1997 the species was considered established in Norwegian greenhouses and it was therefore deleted from the Norwegian A-list. It is now under surveillance as a vector for TSWV (an A-list pest) and is treated as a quarantine pest if discovered in connection with TSWV. The introduction and establishment of F. occidentalis in Norwegian greenhouses has been a burden to both growers and the society. Growers have suffered financial losses in terms of costs of carrying out comprehensive quarantine instructions (1986-1996) as well as through direct crop loss and costs of control measures (1986-2006). Indirect economic impacts of F. occidentalis include the implications for growers due to the quarantine instructions (1987- 1996) such as increased labour to carry out the instructions; cost of pesticides; loss of production time during the quarantine and eradication period; loss of contracts when not able to deliver plants and seedlings on time; loss of reputation; and perhaps as a combination of the others also loss of future contracts. Growers have also suffered in terms of health risks as they have used pesticides more frequently and thereby been exposed to pesticides more often. Very rough estimates and assessments to predict potential crop loss caused by F. occidentalis suggests a worst case scenario (or 100% crop loss) to be about 1454.4 mill NOK per year (2003-numbers). Assuming that the proportion of infested greenhouses at any given time during the year is somewhere between 30-40%, then potential crop losses would be between 436-582 mill NOK per year. It should be underlined that these numbers are rough estimates only, not accurate measurements. Introduction/establishment of the species has resulted in an increased effort from extension service, phytosanitary authorities, and scientists, the costs involved are, however, difficult to assess. […]