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
Foreløpige resultater på effekt av plantestørrelse og herdingsforhold på frosttoleranse i kveke, åkertistel og åkerdylle ble presentert
Forfattere
Hans OvergaardSammendrag
Knowledge of factors that influence oviposition behavior of malaria mosquitoes is critical to vector control measures aimed at larval habitat modifications and source reduction. Anopheles minimus s.l., an important malaria vector in Southeast Asia, generally breeds in clear, unpolluted water along shaded grassy edges of slow-moving streams. The objective of this study was to determine the influence of vegetation and plant structure on An. minimus s.l. ovipositing females. Twenty gravid female mosquitoes per replication were given a choice to lay eggs in bowls surrounded by different combinations of bare soil, grasses, small-leaved plants, and large-leaved plants. An. minimus s.l. females generally preferred to lay eggs in bowls with vegetation. A significantly higher number of eggs were found in bowls with small-leaved plants compared to bowls with grasses (P large-leaved plants > grasses > soil. Further studies are needed to determine the possible roles of plant structure and factors such as semiochemicals in the different species of the An. minimus species complex. Knowledge of female oviposition behavior is essential for the development of locally adapted approaches to source reduction and breeding site interventions.
Sammendrag
Foreløpige resultater på effekt av økning i temperatur og/eller CO2, samt skygging på etterfølgende gjenvekst ved 5-14 "C av kvekejordstengler og røtter av åkerdylle og åkertistel ble presentert.
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