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
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. […]
Abstract
The aim of the present investigation was to study the effect of manure on retention of selenium (Se) in soil. Addition of cattle manure in combination with selenite and selenate reduced the adsorption of both anions to a loam soil in a batch experiment. The results were explained by the content of low-molecular-weight organic acids in the manure which compete with Se for the sorption sites. In a pot experiment with loam and peat soils and with two pH levels within each soil, cattle slurry added together with selenate was found to increase the Se concentration in grain at the highest pH level (6.1 and 6.8 for the loam and peat, respectively). At a lower pH (5.4 and 6.0 for the loam and peat, respectively) there was no significant effect of slurry on Se concentration in grain. Application of slurry also increased the residual effect of Se applied to the loam soil in the preceding growing season. In the peat soil, no residual effect of Se was found either with or without the addition of slurry.
Abstract
Early stage of grass maturity increased the total concentration of fatty acids (FA) and the concentration of alpha-linolenic acid in organic ley compared to normal stage. Organic ley with red clover resulted in higher concentration of alpha-linolenic acid than white clover. Unexpectedly, increased portions of clover in the ley resulted in lower total concentration of FA. Early harvested ley with red clover may result in forage with high concentrations of alpha-linolenic acid and thus provide a good basis for milk production with a healthy composition of milk fat with a low omega-6/omega-3 FA ratio.
Abstract
The effect of clover species and level of concentrate supplementation on milk fatty acid (FA) composition has been studied. White (WC) and red clover (RC) grown in mixture with grasses were preserved in round bales and fed to autumn calving dairy cows during the first 10 weeks of lactation. Milk FA was higher in linolenic acid, vaccenic acid and rumenic acid for RC than for WC silage (0.90 vs. 0.79 %, 1.52 vs. 1.36 %, 0.90 vs. 0.75 % for these 3 FA, respectively), and RC silage gave a higher n-3/n-6 milk FA ratio than WC (0.98 vs. 0.72). Concentrate supplementation decreased the level of vaccenic acid (1.21 vs. 1.68 %), linolenic acid (0.63 vs. 1.05 %) and the n-3/n-6 ratio (0.55 vs. 1.16) as compared with no supplementation, and the effect of supplementation was similar for the two silages
Abstract
The effect of clover species and level of concentrate supplementation on milk fatty acid (FA) composition has been studied. White (WC) and red clover (RC) grown in mixture with grasses were preserved in round bales and fed to autumn calving dairy cows during the first 10 weeks of lactation. Milk FA was higher in linolenic acid, vaccenic acid and rumenic acid for RC than for WC silage (0.90 vs. 0.79 %, 1.52 vs. 1.36 %, 0.90 vs. 0.75 % for these 3 FA, respectively), and RC silage gave a higher n-3/n-6 milk FA ratio than WC (0.98 vs. 0.72). Concentrate supplementation decreased the level of vaccenic acid (1.21 vs. 1.68 %), linolenic acid (0.63 vs. 1.05 %) and the n-3/n-6 ratio (0.55 vs. 1.16) as compared with no supplementation, and the effect of supplementation was similar for the two silages
Authors
Michelle de Chantal Kjersti Holt Hanssen Aksel Granhus Urban Bergsten Mikaell Ottosson-Löfvenius Harald GripAbstract
No abstract has been registered
Abstract
No abstract has been registered