Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2008
Forfattere
Bernt-Håvard Øyen Per Holm NygaardSammendrag
From the first plantings and experiences in the afforestation areas in West and North Norway it became evident that there was a large potential for increasing the yield by changing tree species, especially from mismanaged broadleaves and pine to dense spruce plantations. The focal point in this chapter will therefore be the experience in Norway, with some examplesfrom other countries.....
Sammendrag
A 2 x 2 factorial continuous experiment was conducted with 28 Norwegian Red dairy cows in early lactation to compare milk content of phytoestrogens when feeding ad libitum white clover (WCS) or red clover (RCS) grass silages prepared from the second and third cut without and with 10 kg/d supplementation of a standard concentrate. The cows were offered either RCS or WCS for 88 d (period 1) and thereafter a mixed red clover-white clover-grass silage for 48 d (period 2). Total dry matter intake and milk yield were not affected by forage type but increased with concentrate supplementation. Intake of isoflavones was several times greater in RCS than in WCS, whereas intake of lignans was greater in WCS. Concentrate supplementation reduced the intake of most phytoestrogens. Compared with WCS, RCS diets yielded milk with a greater content of flavonoids, whereas milk from WCS diets had greater contents of the mammalian lignans enterodiol and enterolactone. The content of the isoflavan equol was particularly high in RCS diets. There was no apparent carryover effect of clover type on milk phytoestrogen content because there was no difference in content between the silage treatments 3 wk after the cows were transferred to the same silage diet (period 2). Concentrate supplementation reduced the milk contents of the flavonoids equol, biochanin A, and daidzein and increased the content of mammalian lignans. The effects of silage type and concentrate supplementation on milk contents of the individual phytoestrogens were related to the intake of the compound or its precursor, except for the effect of concentrate on mammalian lignans, for which the intake of the known precursors was also reduced. Overall, this study shows that feeding cows with silage containing red clover increases the milk content of flavonoids at both low and high concentrate supplementation levels, and decreases the content of nonflavonoids such as mammalian lignans, when compared with silage containing white clover. The increased content of phytoestrogens in milk may be important when the health benefits of milk are studied.
Sammendrag
In order to improve the basis for utilizing white clover (Trifolium repens L) in northern agriculture, we studied the effects of defoliation intensity on spring growth in a sub-arctic climate in relation to carbohydrate and nodule status. White clover plants (cv Snowy) were studied in a pot experiment in the field on the coast of northern Norway from spring 2001 until spring 2002. The experiment was repeated with some modifications from spring 2002 until spring 2003. During the growing season from summer to autumn, the plants were totally stripped of leaves down to the stolon, cut at four or seven cm height or left undisturbed. The plants were sampled destructively in autumn, early spring and late spring and sorted into leaves, stolons and roots. The plant material was weighed and analysed for carbohydrate reserves and nodule number. Defoliation during the growing season resulted in reduced concentration of reserve carbohydrates in autumn and reduced winter survival of the stolons. The most severe defoliation treatment reduced the herbage growth in spring. In contrast, the two milder defoliation treatments had no effect on herbage growth during spring or on total plant dry matter and nodule status in late spring. In conclusion, moderate defoliation during the growing season had no effect on herbage growth the following spring nor on carbohydrate, nodule or dry matter status of the plant in late spring. Moderate defoliation increased spring growth and thereby also the nitrogen demand of the plants. This probably enhanced nodule formation and development of inactive to active nodules.
Forfattere
Mekjell Meland Magne Eivind MoeSammendrag
The apple cultivar `Elstar" is the latest is the latest commercial maturing cultivar in Norway of high fruit quality when properly managed. In May 2006 a four years experiment with four different crop loads (2-4-6-8 flowers/fruitlets per TCSA cm2) were established at two stages (first bloom open and 20 mm fruitlets diameter) and compared to unthinned. Preliminary results from the two first seasons are presented. Fruit growth determination was conducted on individual fruits on each treatment during the season. Thinning at bloom to different crop levels gave a significant lower fruit set than thinning at the fruitlets stages to the same levels the first year. However, the fruit weight and the soluble solid contents were significant larger and ground colour improved when bloom thinning. The final fruit numbers at harvested was less than the amount established at bloom and fruitlets. There were significant differences between the different treatments in final fruits per TCSA and fruit set which reflected the different crop levels. Fruit weight and soluble solid contents were largest with lowest crop load and decreased with increasing crop levels. There was a strong crop load effect from the year before on the amounts of return bloom per tree. The trees thinned at bloom had significant more flower clusters than thinned at the fruitlet stage of 20 mm. The untreated, control trees had the lowest amount of flower clusters. The amount of return bloom declined with increasing crop load on the trees. The second year yield and fruit weight were larger when thinned at bloom. The highest crop load the second year was when thinned at bloom to the levels of 2 and 4 apples per TCSA the year before. The trees with the highest crop load the last year managed to give only a small crop. The fruit quality was in general high for all treatments.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Timotei hadde større toleranse til isdekke enn flerårig raigras. Det var en sterk korrelasjon mellom isdekketoleranse og frosttoleranse, og sorter som er mer frosttolerante overlevde lengre under isdekke enn mindre froosttolerante sorter. Både frosttoleranse og isdekketoleranse økte fra november til januar, men avtok deretter i mars.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Knut Anders HovstadSammendrag
This study examines the impact of plant litter on seedling establishment in a semi-natural grassland. In a field experiment, seeds of six forbs were sown in plots subjected to either different litter quantities or addition of water extracts of litter. The response to plant litter was species specific. High quantities of litter resulted in a negative response in all species except Anthriscus sylvestris. In some of the species, the response shifted from positive or neutral at intermediate litter quantities, to negative at high litter quantities. This suggests that facilitative effects were present, although inhibitory effects dominated at high litter quantities. The physical effects were generally stronger than the chemical effects. However, water extract of litter inhibited emergence in three of the six species. Filtration using activated carbon removed the negative effect of litter extract, which suggests that the effect was caused by inhibitory compounds adsorbed by activated carbon (e.g. polyphenols) rather than by increased competition in response to nutrients added via the extract.
Sammendrag
Effects of temperature on the development and chemical composition of two cloudberries (Rubus chamaemorus L.) cultivars ("Fjellgull", "Nyby") were studied in a phytotron experiment. "Fjellgull" is a female cultivar while "Nyby" is bisexual (hermaphrodite). Pollen from a male cultivar "Apollen" or from "Nyby" was used to pollinate "Fjellgull". Selfpollination in "Nyby" was assisted by striking open flowers gently with a small brush. In addition, part of the flowers of both cultivars were treated with gibberellic acid (GA3, 10 µg dissolved in 10 µl ethanol). Plants were grown in 24-h photoperiod at constant temperatures of 18, 15, 12 and 9°C. Time from pollination to ripening increased in both cultivars with decreasing temperature from about 35 days at 18°C to about 60-65 days at 9°C. Time for fruit development was not significantly affected by GA3. Berries of "Fjellgull" were significantly larger than those of "Nyby". In both cultivars, the largest berries were found at the treatments 12 or 9°C. On the other hand, seed size was smallest at 9°C and the proportion of seed weight of total fresh weight of berry decreased with decreasing temperature. Treatment with GA3 significantly reduced the average seed size in both cultivars. Pollen type had no significant effect on the rate of development or size of berries in "Fjellgull". Ripe berries were frozen at harvest at -100°C, and tannin enriched extracts were analyzed for metabolites using liquid chromatograpy " mass spectrometric (LC-MS) techniques. In addition total phenols and total anthocyanins were analysed as described by Deighton et al. (2000). Statistical analysis and data mining were performed using a principal component analysis approach. Preliminary results indicate differences in the metabolic profiles between berries grown at low temperatures compared to berries grown at high temperatures.