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.
2009
Sammendrag
Results from the study "Effects of metabolic changes during cold hardening on freezing survival of Agrostis spp." were presented. The objectives of the trial were: (1) to compare freezing tolerance of velvet bentgrass and creeping bentgrass, (2) to quantify carbohydrate and protein changes during the two consecutive phases of cold acclimation in these species, and (3) to compare one direct and two indirect methods for determination of LT50 in turfgrasses. Four treatments representing different phases of cold acclimation were compared: (i) non-acclimated (NA) plants maintained at 18 / 12 °C (day/night); (ii) plants acclimated at 2 °C for 2 wk (A2); (iii) plants acclimated at 2 °C for 4 wk (A4); and (iv) plants acclimated at 2 °C for 4 wk with an additional sub-zero acclimation in the dark at -2 °C for 2 wk (A4+SZA2). Velvet bentgrass and creeping bentgrass showed no difference in lethal temperatures for 50% of the test population (LT50) as estimated by whole plant survival. Treatments A2 and A4 resulted in accumulation of sucrose and fructans, and significantly lowered LT50 as compared with NA. A4+SZA2 resulted in less fructans, no difference in sucrose and higher concentration of reducing sugars but LT50 was not lower than after A4 treatment. Crown viability determined by reduction of tetrazolium chloride showed close correlation with LT50 values based on whole plant survival. Electrolyte leakage produced less consistent results and cannot be recommend as a quick method for evaluation of relative hardiness of the rather small crowns of bentgrass species, especially not if acclimation at subfreezing temperatures is part of the testing procedure.
Forfattere
Tatsiana EspevigSammendrag
Preliminary results from the study "Effects of metabolic changes during cold hardening on freezing survival of Agrostis spp." were presented. The objectives of the trial were: (1) to compare freezing tolerance of velvet bentgrass and creeping bentgrass, (2) to quantify carbohydrate and protein changes during the two consecutive phases of cold acclimation in these species, and (3) to compare one direct and two indirect methods for determination of LT50 in turfgrasses. Three (of four) treatments representing different phases of cold acclimation were compared: (i) nonacclimated (NA) plants maintained at 18 °C/12 °C (day/night); (ii) plants acclimated at 2 °C for 2 wk and 250 μmol m-2 s-1 for 12 h photoperiod (A2); and (iii) as treatment (ii) but for 4 wk (A4). Plants exposed to additional sub-zero acclimation in the dark at -2 °C for 2 wk (A4+SZA2) were under acclimation treatment at that time. Results regarding 1st and 3rd objectives were discussed. Acclimation at 2 ºC significantly improved freezing tolerance of both species, but differences between species were not significant. The LT50 for plants subjected to A2 and A4 were 4 and 6 °C lower, respectively, compared to NA plants. Crown viability test had a good correlation with the LT50 based on whole plant survival. Electrolyte leakage underestimated freezing survival ability in Agrostis spp.
Forfattere
Tatsiana EspevigSammendrag
One of the major concerns for the use of velvet bentgrass (Agrostis canina) in Scandinavia is whether current cultivars have sufficient winter hardiness. To meet this challenge, velvet bentgrass (VB) cultivars were tested for winter hardiness in controlled environments at UMB during 2006/2007. Hardened and unhardened VB cultivars Avalon, Villa, Greenwich and Legendary were compared with creeping bentgrass (CB, Agrostis stolonifera) cv. Penn A-4 (control) for freezing tolerance. There were no differences in freezing tolerance between velvet and creeping bentgrass, but none of the tested cultivars, whether hardened or not, tolerated freezing to - 9 ºC or lower.That became a background for the collaborative project between the Norwegian Institute of Agricultural and Environmental Research (Bioforsk), Norwegian University of Life Science, Rutgers University and the University of Massachusetts. The objectives of the project would be: (1) to compare freezing tolerance of VB and CB, (2) to quantify carbohydrate changes during the two consecutive phases of cold acclimation in these species, and (3) to compare one direct and two indirect methods for determination of LT50 in turfgrasses.
Sammendrag
Vinter overlevelse og kontroll av rask filt akkumulering er to sentrale utfordringer ved bruk av hundekvein på golfbaner i Norden. Målet av prosjektet "VELVET GREEN: Overvintring og skjøtsel av hundekvein på golfgreener" er å vurdere vinter herdigheten til den arten og å finne effektene av vekstmedium, vanning, gjødsling, toppdressing, samt mekaniske og biologisk tiltak for filtkontroll. Så langt anbefaler vi å redusere gjødsling og vanning så snart greenen med hundekvein er etablert. I tillegg må man redusere filt med å fjerne den mekanisk og å tilføre sand (toppdressing). Resultater fra forsøkene under kontrolert klima viser at hundekvein hadde tilnærmet samme frosttoleranse som krypkvein.
Sammendrag
Pink snow mould brings a lot of injury on golf courses in cool and cold regions all over the world. There is unnecessary use of fungicides to date because the injury or even sporadic epidemics caused by the disease are difficult to predict. Improved knowledge about biology, ecology and genetics of Microdochium nivale furthers the development of alternative methods for IPM of pink snow mould.
Sammendrag
Forskingsprosjektet "VELVET GREEN: Overvintring og skjøtsel av hundekvein på golfgreener" er et av de mest omfattende som hittil er finansiert av nordiske golfspillere gjennom stiftelsen "Scandinavian Turfgrass and Environment Research Foundation (STERF)". Foruten forsøk i kontrollert klima på Universitet for Miljø og Biovitenskap (Ås) og feltforsøk på Bioforsks sentre Landvik (Grimstad) og Apelsvoll (Toten) omfatter prosjektet praktisk utprøving av hundekvein på golfbaner i Finland, Sverige, Norge og Danmark. Sammen med rådgivere og forskere fra de ulike land utgjør headgreenkeeperne på disse banene prosjektets referansegruppe. I juni var denne gruppa samlet på Apelsvoll for å utveksle erfaringer så langt i prosjektet. De praktiske erfaringene til greenkeeperne i referansegruppa er et nødvendig supplement til forsøksresultatene som kommer ut av prosjektet. Erfaringene viser at utfordringen med hundekvein på golfbaner i Norden ikke er overvintringa, men å finne fram til skjøtselrutiner som kontrollerer det organiske materiale og forekomsten av sykdommer i vekstsesongen. Så snart greenen er inngrodd må gjødsling og vanning reduseres, men riktig nivå avhenger av vekstmedium, spilletrykk, klimaforhold og mange andre faktorer. På nye greener vil hundekvein gi rask etablering og tidlig baneåpning, men hvis skader først oppstår, er reparasjonsevnen dårligere enn for krypkvein.
Forfattere
N. Abrantes Randi Bolli Gro Hege Ludvigsen Olav Lode F. Goncalves Ole Martin Eklo Lillian Øygarden J.J. KeizerSammendrag
Det er ikke registrert sammendrag
Forfattere
Ketil HaarstadSammendrag
Det er ikke registrert sammendrag
Forfattere
Ketil Haarstad Pengxin Zhang Per Aagaard Farrokh Nadim Lars GottschalkSammendrag
The use of pesticides is a potential threat to local groundwater. Once groundwater is contaminated, it is very difficult to clean.Thus, it is of importance to assess the risk of contaminating local groundwater at an early stage when pesticides are found in soils. This knowledge will also help in remediation strategies. Traditional methods of deterministic analysis cannot explicitly account for the sometimes large uncertainties that exist at this stage in the work, whereas probabilistic analyses are better suited for dealing with these problems. In this paper, we have combined contaminant transport with a 1st-order reliability approach. Pesticide concentrations in soil have been studied to estimate the probability of failure—that is, of pesticides exceeding established critical levels in groundwater. Results indict that failure probability increases rapidly with in a certain range of pesticide concentrations in soil for different critical levels. In given aquifer conditions and contaminants, probabilities of contaminants exceeding particular critical levels can easily be obtained according to various water usage scenarios. The distribution of importance factors among variables indicates the contribution their relative weights make to the failure probability. Hence, authorities can easily form sensitivity factors to take action and reduce the risk of contaminating the groundwater.
Sammendrag
Colour has increased significantly in several Norwegian rivers and lakes over the past two - three decades (Haaland et al. 2007; de Wit et al. 2007). This has also been observed throughout Northern hemisphere (Forsberg and Petersen 1990; Freeman et al. 2001; Roulet and Moore 2006; Tranvik and Jansson 2002). The long term increase in colour has coincided with the decline in anthropogenic acid emissions which peaked in Europe around mid 1970s (Schöpp et al. 2003). During the earlier days of the acid rain history, Krug and Frink (1983) hypothesised that acid rain possibly could explain the previously reduced colour in lakes observed on the Northern hemisphere. The increase in colour and concentrations of organic carbon in lakes throughout the past decades have by several authors again been linked to the reduction of atmospheric acid emission, in the UK (Evans et al. 2006), in Norway (de Wit et al. 2007) and in northern Europe and northern America (Monteith et al. 2007).