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
Sammendrag
Foreløping resultater på effekt av klimaendring på etterfølgende gjenvekst av kvekejordstengler, røtter av åkertistel og åkerdylle ble presentert.
Forfattere
Trygve S. Aamlid Peter LandschootSammendrag
Spent mushroom substrate (SMS) is used by the turf industry in the northeastern United States for soil improvement. When tilled into soil at high rates, some turfgrass managers claim that SMS inhibits turf seed germination. Our objectives were 1) to determine if fresh SMS inhibits turf seed germination and, if so, which species are most adversely affected; 2) to evaluate whether any inhibition caused by SMS is due to osmotic effects or toxicity of compounds in SMS extracts; 3) to determine if any negative effect of SMS on germination can be eliminated by leaching the SMS-amended soil before seeding; and 4) to assess the performance of SMS on seedling emergence in the field. Germination of nine turfgrass species was evaluated in mixtures made from fresh SMS [electrical conductivity of saturated paste extract (ECe) = 11.9 dS m-1] and a loamy sand soil. Germination inhibition due to SMS was most pronounced in the following order: Colonial bentgrass (Agrostis capillaris L.) > sheep fescue (Festuca ovina L. ssp. hirtula [Hackel ex Travis] Wilkinson) > Kentucky bluegrass (Poa pratensis L.) > hard fescue (Festuca trachyphylla [Hackel] Krajina]) > creeping bentgrass (Agrostis stolonifera L.) > Chewings fescue (Festuca rubra L. sp. commutata [Thuill.] Nyman) = strong creeping red fescue (Festuca rubra L. ssp. rubra Gaud.) > slender creeping red fescue (Festuca rubra L. sp. litoralis [Meyer] Auquier) > perennial ryegrass (Lolium perenne L.). SMS had a stronger negative effect on germination rates (GRs) than on final germination percentages (FGPs). Germination of perennial ryegrass and Kentucky bluegrass on blotter paper moisted with SMS-extracts or polyethylene glycol of equivalent osmotic potentials showed that the inhibition was primarily due to osmotic effects. In an experiment with a 50% soil / 50% SMS (v/v) mixture, Kentucky bluegrass germinated better in pots that had been watered with 133 or 167% of the evaporation rate for ten days prior to seeding than in unleached pots. Although the negative effect of SMS on seed germination was not confirmed in a field study where ECe values never exceeded 4.1 dS m-1, we conclude that incorporation of high rates of SMS represents a potential problem for turfgrass establishment.
Forfattere
Ketil Kohmann Øystein JohnsenSammendrag
The object of this study was to obtain Norway spruce seedlings with buds set, ready for summer planting from the 1st of July. With an early long night treatment we prevented flushing of the newly formed terminal buds, ceased height growth, but slightly reduced hardiness in buds and needles. Nevertheless, a sufficient hardiness level in the autumn was acquired at a Norwegian nursery at 59°46’ N, with plants of the local provenance given a long night treatment (14 hours) for 13 days from the 25th of June. The similar treatment at a nursery at 64°30’N did not give the same result; all treatments led to a second flush with resumed growth of the local provenance. A trial with seed lots from several provenances was therefore performed at this nursery, and a significant correlation between the critical night length of the seed lot, and their ability to produce non-flushing buds, was found; the longer the critical night length of the seed lot, the less non-flushing buds. Responses at the northern nursery are probably due to the non existing dark period after termination of the treatment, and a too short treatment period to attain bud dormancy. An early and successful long-night treatment will, in addition, produce shorter seedlings with a larger root collar diameter.
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
Det er ikke registrert sammendrag
Forfattere
Lillian ØygardenSammendrag
Det er ikke registrert sammendrag
Forfattere
Lillian ØygardenSammendrag
Det er ikke registrert sammendrag
Forfattere
I.A. Rasmussen D.L. Benoit A. Davies F. Forcella J.L. Gonzalez-Andujar F. Graziani A.C. Grundy L. Karlsson A. Mead P. Milberg A. Murdoch P. Neve J. Salonen B. Sera E. Sousa F. Tei Kirsten Tørresen J.M. UrbanoSammendrag
Samspill mellom oppspiringsforhold, opphavssted til frø og jordarbeiding på oppspiring av meldestokk på 11 ulike steder i Europa og Nord-Amerika ble presentert.
Forfattere
Trygve S. Aamlid Nicholas JarvisSammendrag
Soil water repellency (hydrophobicity) is a common problem on sand-based golf greens. Due to this phenomenon, soil water may percolate as "finger flow" rather than uniformly through the soil profile. The objective of this project was to investigate the effect of a commonly used wetting agent, Primer 604, on turf quality and leaching of two fungicides from two contrasting rootzones. The preliminary conclusions are as follows: 1. The wetting agent (WA) improved turf quality of straight sand rootzones during the warm and dry summer. Rootzone containing compost were not affected by WA. 2. WA lead to more water retention in the thatch layer and thus a tendency to more fungi during the rainy fall season. Again, the effect was mostly expressed on straight sand rootzones. 3. Water droplet intiltration tests showed that straight sand rootzones were strongly hydrophobic, even at 3-5 cm depth, i.e. under the thatch layer. Compost-amended rootzones were less hydrophobic, and only in the thatch layer. 4. WA reduced the spatial variation in soil water content, notably in the 4-15 cm layer on straight sand plots. This suggest that water percolation was more uniform after use of WA. 5. Fungicide leaching did not occur from Green Mix rootzones, even for azoxystobin + propicionazole used at high "American" rates. 6. Use of WA significantly reduced leaching of the fungicides iprodione, azoxystrobin and propiconazole from straight sand rootzones.
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.