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.
2007
Forfattere
Arnstein Staverløkk May-Guri Saethre Eline Benestad HågvarSammendrag
The invasive ladybird, Harmonia axyridis Pallas 1773, is recorded for the first time in Norway. The specimen was found on horticultural plants imported from Aalsmeer in the Netherlands to Oslo, Norway. H. axyridis originates from East-Asia. The species is known to be a voracious predator on aphids and has been extensively used as a biological control agent in both North America and Europe. The later years, however, a number of negative impacts on the environment and biodiversity have been reported. The species was assessed as a potential bio-control agent for use in Norwegian greenhouses in 2001. The outcome of the assessment was negative with respect to import and commercial use in Norway. It was concluded that H. axyridis might survive and become established outdoors and thereby pose a risk to the environment. Recent experiences from the UK have shown that H. axyridis compasses several of the traits characterizing a successful invasive alien species. The record of this species in Norway may only be the first in a number of such, as it is likely that this species will survive outdoors, at least in the southern parts of Norway.
Forfattere
jihong liu clarkeSammendrag
The complete sequences of the chloroplast genomes of H. vulgare, Sorghum bicolor and A. stolonifera are presented. The sizes of the H. vulgare, Sorghum bicolor and A. stolonifera chloroplast genomes are 136,462, 140,754 and 136,584 bp, respectively. The genomes include a pair of IRs of 21,579 bp (H. vulgare), 22,782 bp (Sorghum bicolor) and 21,649 bp (A. stolonifera) separated by a small single copy region of 12,704 bp (H. vulgare), 12,502 bp (Sorghum bicolor) and 12,740 bp (A. stolonifera) and a large single copy region of 80,600 bp (H. vulgare), 82,688 bp (Sorghum bicolor) and 80,546 bp (A. stolonifera). Comparisons of complete chloroplast genome sequences of Hordeum vulgare, Sorghum bicolor and Agrostis stolonifera with six published grass chloroplast genomes reveal that gene content and order are similar but two microstructural changes have occurred. First, the expansion of the IR at the SSC/IRa boundary that duplicates a portion of the 5" end of ndhH is restricted to the three genera of the subfamily Pooideae (Agrostis, Hordeum and Triticum). Second, a 6 bp deletion in ndhK is shared by Agrostis, Hordeum, Oryza and Triticum, and this event supports the sister relationship between the subfamilies Erhartoideae and Pooideae. Repeat analysis identified 19- 37 direct and inverted repeats 30 bp or longer with a sequence identity of at least 90%. Seventeen of the 26 shared repeats are found in all the grass chloroplast genomes examined and are located in the same genes or intergenic spacer (IGS) regions. Examination of simple sequence repeats (SSRs) identified 16"21 potential polymorphic SSRs. Five IGS regions have 100% sequence identity among Zea mays, Saccharum officinarum and Sorghum bicolor, whereas no spacer regions were identical among Oryza sativa, Triticum aestivum, H. vulgare and A. stolonifera despite their close phylogenetic relationship. The genome information will facilitate the development of CP technology for those crops to improve their agronomic traits.
Forfattere
Trygve S. Aamlid Gunvald Henning JonassenSammendrag
Field trials comparing various combinations of 0, 30 or 60 kg N ha-1 in autumn (September) and/or spring (April) to seed crops of common bent (syn. browntop, US: colonial bentgrass, Agrostis capillaris L.) "Leikvin" (main use: long-lasting pastures and utility turf) and "Nor" (main use: lawns and golf course fairways) were carried out on silt loam soils at Landvik, south-east Norway (58°N) from 1989 to 1994. One trial per cultivar was established in 1989, 1990 and 1991, each trial being harvested for three years. On average, for nine harvests and nine N treatments, "Leikvin" and "Nor" gave seed yields of 276 and 128 kg ha-1, respectively. Seed yields of "Leikvin" increased with increasing N rate up to 60 kg N ha-1 in autumn and 30 kg N ha-1 in spring; no interaction between autumn and spring N rate could be detected in this cultivar. In "Nor", a significant autumn x spring rate interaction indicated a linear seed yield response to N in spring on plots that had received 60 kg N ha-1 in autumn, but a diminishing response to N in spring on plots that had received 0 or 30 kg N ha-1 in autumn; the highest seed yield was produced with autumn + spring applications of 60 + 60 kg N ha-1 in this lawn cultivar. While panicle number and seed number per panicle were equally important for seed yield in "Leikvin", panicle number had the stronger impact on seed yield in"Nor". Seed crops of "Leikvin" were generally taller and more susceptible to lodging than seed crops of "Nor". Year-to-year variations in seed yield level and optimal N regime were less related to crop age than to weather conditions and seed crop management. Given the present prices for fertilizer and seed, it is concluded that Norwegian seed crops of common bent should receive 50-60 kg N ha-1 in autumn regardless of cultivar. Economically optimal N rates in spring are 30 and 60 kg N ha-1 to "Leikvin" and "Nor", respectively.
Forfattere
Nina Opstad Arnfinn Nes Finn MågeSammendrag
I et feltforsøk med jordbær plantet på Østlandet, ble tørrgjødsling ved planting i august 2003 sammenliknet med gjødselvatning fra mai 2004. Halve feltet ble gjødslet ved planting og ble gjødselvatnet med en lav gjødselrate fra våren etter (T1), mens den andre halvparten var ugjødslet ved planting og ble i stedet gjødselvatnet med høg gjødselrate fra våren 2004 (T2). I 2005 fikk begge leddene tilført samme mengde gjødsel. Ingen av behandlingene medførte noen mangelsymptomer i løpet av forsøket, men av alle parametrene som ble registrert, var det bare antall blad og bladareal som kompenserte for den begrensa næringstilgangen om høsten. Avling og bærstørrelse var signifikant høgere i T1 i det første avlingsåret, på tross av den lave gjødselraten i avlingsåret. Året etter ble det ikke funnet noen signifikante forskjeller mellom T1 og T2. Blad og bladstikler ble samlet flere ganger gjennom sesongen, og tørrstoff og bladsaft ble analysert for makro- og mikronæringsstoff. Det var få signifikante forskjeller mellom behandlingene, men det var en tendens til at bladsaftanalysene sa mest om det aktuelle opptaket i blad. Hverken tørrstoffanalyser eller bladsaftanalyser i sesongen gjenspeilet avlingspotensialet, da det var underoptimale forhold om høsten som reduserte bærstørrelsen i T2.
Forfattere
Nina Opstad Arnfinn Nes Finn Måge Bjørn HagebergSammendrag
Two-year-old blackcurrant plants cv. Ben Tron were planted in 1991 to investigate long-term effects of seven fertilization strategies. Broadcast fertilization was given in spring and autumn, fertigation from May until August, or a combination of fertigation and broadcast fertilization. Three fertilizer rates were used, and the amount was increased three times during the trial because of low mineral content in the leaves and insignificant yield response. Yield parameters, macro nutrient content in leaves and content of soluble solids in fruit juice were recorded over 11 years. The variation between years was significant for all parameters recorded, but the fertilization strategies had only a minor effect over time. Content of macro nutrients in leaves was low compared to recommended values, and did not respond significantly to increasing fertilizer amounts. Yield decreased with plant age. Frost reduced yield in at least two years, but few significant correlations with precipitation and temperature were found. A good water access seems to be important for a stable fruit yield, while precipitation during flowering is likely to reduce yield because of fruit drop.
Sammendrag
Quantifying P losses to surface waters at different scales and partitioning of the loads into P losses from point sources and diffuse sources are significant future challenges for river basin managers. The agricultural share of P losses to surface waters is, in many river basins, increasing and therefore becoming more important to quantify and analyse. The importance of phosphorus losses from agricultural land was analysed using monitoring data and two different models for 35 micro-catchments (50 000 km2). Average annual phosphorus loss from agricultural land in the micro-catchments varied from 0.1 to 4.7 kg P ha)1 and showed no relationship with the short-term P surplus on agricultural land. The average annual total P loss from agricultural land showed equally large variation in the 17 macro-catchments (0.1"6.0 kg P ha)1), but the range was less for the 10 larger river basins (0.09"2.0 kg P ha)1). The annual P loss from the 35 micro-catchments was greatest in the micro-catchments characterized by soil erosion and a high proportion of surface run-off as in the Norwegian catchments. The same pattern was true for the 17 macro-catchments where the model-simulated total P loss from agricultural land was greatest in the catchments in northern and southern parts of Europe. The main diffuse pathways for total P loads in the 17 macro-catchments were simulated with the MONERIS model. On average, soil erosion and surface run-off was estimated to have contributed 53% (4.1"81%), groundwater 14% (0.2"41.7%) and tile drainage water 3% (0"14.0%).
Sammendrag
Numerous fungicide applications are often needed to control powdery mildews in greenhouse-grown crops, and consequently there is an increasing demand for alternative means to control them. In commercial greenhouses, attack of powdery mildew caused by Podosphaera xanthii in cucumbers and P. pannosa in cut roses was controlled by weekly sprays of C-Pro CE601, a dilution of grapefruit seed extract (GSE). The raw material of GSE, delivered by Citricidalâ, is a glycerolic extract from seed and juiceless pulp of grapefruits (Citrus paradise). In both cultures C-Pro at 2000 ppm achieved as good control as treatments with penconazole or triforine. The mean level of attack by powdery mildew on leaves of cut roses one week after the last of three weekly treatments, was 9.8, 12.9 and 40.5 % for penconazole, C-Pro (2000 ppm), and untreated, respectively. In cucumbers, there was less difference between the untreated control and the different treatments, but for all times of assessments, C-Pro and triforine were better than untreated (P = 0.001). There was no significant difference in cucumber between C-Pro and triforine. Phytotoxicity symptoms like leaf twisting and rolling in roses (cv. Jade and Cezann) and dark green leaves and indications of growth retardation in cucumbers (cv. Ventura) were observed at the higher concentrations used (3000-4000 ppm). Thin layer chromatography of C-Pro CE601 has previously shown presence of benzethonium chloride, a synthetic antiseptic agent. Further research is necessary to determine if the observed effects of the product tested are due to natural compounds or if it is merely due to a synthetic preservative agent added. Our results revealed that C-Pro might be a supplement or even a replacement to some of the current fungicides used against powdery mildew.
Forfattere
Trygve S. Aamlid Oiva NiemelainenSammendrag
The plant growth regulator Primo Maxx (trinexapac-ethyl) is being evaluated on greens and fairways in a joint Finnish-Norwegain project 2007-2008. Trials are beeing carried out at Bioforsk Øst Landvik and Ballerud Golf Club, Norway and Lepaa Golf course, Finland. Preliminary results from 2007 indicate reductions in clipping yeids varying from 10 to 50%. Depending on dosage, visual turf quality is either unaffected or decreased, mainly due to a more uneven appearance and less competition against weeds.
Forfattere
Trygve S. Aamlid Larsbo Mats Nick JarvisSammendrag
Fungi, especially those causing winter diseases, are major problems on golf course putting greens in Scandinavia. Although diseases can be prevented by cultivar selection and optimal maintenance, it is difficult to manage creeping bentgrass (Agrostis stolonifera) and annual bluegrass (Poa annua) greens totally without fungicides. Previous research showed that three commonly used fungicides; iprodione, azoxystrobin, and propiconazole, are liable to leaching when used on sand-based putting greens. One possible reason for this liability is the development of hydrophobic layers or spots causing water to percolate in fingers instead of uniformly through the root zone. The objective of this project was to study the effect of organic amendment and surfactant on turfgrass quality, hydrophobicity and fungicide leaching from a USGA putting green. An experiment was conducted from May 2006 till May 2007 on a three year old experimental green seeded to creeping bentgrass `Penn A-4" in the field lysimeter facility at Bioforsk Øst Landvik, SE Norway (Fig. 1). The experimental plan included two root zone compositions (straight sand vs the same sand amended with 2.3 % (w/w) garden compost (`Green Mix")); two surfactant treatments (no surfactant vs `Primer 604", 19 L/ha applied at monthly intervals from May to September 2006); and two fungicides, Rovral 750 (iprodione 1.5 kg a.i./ha) and Amistar Duo (azoxystrobin + propiconazole, 600 + 375 g a.i./ha), sprayed on three occasions; June, July and October 2006) in factorial combination. Turfgrass quality and disease occurrence, infiltration of water vs ethanol, water droplet penetration time, and spatial variability in soil water content was determined at regular time intervals. Fungicides in leaching water were analyzed 2 - 3 weeks after each application and after snow melt / soil thaw in spring 2007. Regular application of `Primer 604" reduced dry spot occurrence and improved turfgrass quality during the summer months, especially on straight sand plots. This improvement was associated with increased water infiltration rates and a reduction in the spatial variability in soil water content at 4 - 10 cm depth, suggesting that hydrophobicity extended deeper in the profile than the 14 - 19 mm thatch/mat layer. However, despite pesticide application, `Primer 604" also increased snow mold (Microdochioum nivale and Typhula spp.) incidence in spring 2007, probably because of a significant increase in the mean soil water content in the thatch"mat layer during the unusually mild and wet winter months (mean temperature / total precipitation from November 2006 to March 2007 was 3.5°C / 751 mm compared with 30 yr normal of 0.2°C / 516 mm). Leaching of fungicides from root zones with 2.3 % organic matter was always negligible, but, regular use of `Primer 604" on rootzones reduced the total leaching of iprodione, azoxystrobin, and propiconazole from straight sand with 60, 63 and 80 %, respectively. In conclusion, `Primer 604" offers many advantages on straight sand rootzones, but there is also a need for new surfactants that retain less water in the thatch layer during the winter months.
Forfattere
Liv Nilsen Liv Guri VelleSammendrag
The Tarva Archipelago is situated on the outer coast of central Norway in the county of Sør-Trøndelag. The islands of Tarva are one of the larges and best preserved area of coastal heathland in central Norway.