Liv Østrem

Forsker

(+47) 909 58 964
liv.ostrem@nibio.no

Sted
Fureneset

Besøksadresse
Fure, 6967 Hellevik i fjaler

Sammendrag

Forlenget vekstsesong gir mulighet for flere slåtter. Kan dette, kombinert med andre arter i frøblandingene, gi mer å hente i form av kvalitetsfôr? Større husdyrproduksjon basert på større andel lokalt grovfôr? Ja.

Sammendrag

Lyssiv og knappsiv finst i stadig aukande omfang på Vestlandskysten, lyssiv meir enn knappsiv. Begge artane har ein agressiv veksemåte. Sivplantene kan raskt dominera i eit beite dersom dei ikkje blir kutta, noko som helst bør gjerast på seinsommar eller hausten. Utan kutting vil dei grøne stenglane samla næringsreservar utover hausten og om vinteren, og siv vil dermed ha eit stort konkurransefortrinn i høve til engvekstane om våren. Utan kjemiske eller mekaniske tiltak utviklar siv seg raskt til eit problemugras.

Sammendrag

Moderat timoteimengde og fleire artar i frøblandingar gir stor avling og ei god utnytting av vekstsesongen. Tre slåttar gav i forsøk meir fordøyeleg tørrstoffavling enn to slåttar, som inneber fleire fôreiningar på arealet.

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Sammendrag

In a ×Festulolium population (FuRs0357) of parental origin Lolium perenne × Festuca pratensis, selection of freezing tolerance by freezing tests on whole plants (FT) and chlorophyll a (Chl-a) fluorimetry on frozen detached leaves (CF) was assessed in high and low directions during two cycles of selection. The original population went through two cycles of random mating. All selections and non-selected intercrossed generations of the original population were established in field trials at a coastal site and a continental site in Norway. At the coastal site, analyses of Chl-a fluorimetry parameters and leaf growth on individual plants in autumn and winter hardiness observed in field plots in spring showed that the first-generation selections for high freezing tolerance were associated with winter hardiness and early growth cessation. The second-generation FT-selections for high freezing tolerance were also associated with winter hardiness, whereas the CF-high selections diverged toward high photosynthetic activity. Both low selections were correlated with high photosynthetic activity. There were smaller variations between generations in unselected generations of the original population. Low accumulated leaf growth and early growth cessation were observed in the secondgeneration FT-selection for high freezing tolerance, whereas high normalized difference vegetation index (NDVI) were seen in Chl-a selections. Both selection methods distinguished diverging selections with significantly different high and low freezing tolerance, but selection efficiency was comparable only for the first selection cycle. Moreover, due to mixed ploidy level in the original population, selection by FT and CF generated diploid and tetraploid plants, respectively, which intensified the response of selection, particularly in the diploid selections. Total dry matter yield (DMY) (mean of three annual cuts for 3 years) of the FT-high selections was lower than for the CF-selections. At coastal sites, selection intensity using freezing tests on whole plants should be adapted to actual climate conditions, to obtain genotypes that balance photosynthetic activity during autumn and good winter hardiness, making them persistent and high yielding.

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1. A core tenet of functional ecology is that the vast phenotypic diversity observed in the plant kingdom could be partly generated by a trade-off between the ability of plants to grow quickly and acquire resources in rich environments vs. the ability to conserve resources and avoid mortality under stress. However, experimental demonstrations remain scarce and potentially blurred by phylogenetic constraints in cross-species analyses. Here, we experimentally decoupled growth potential and stress survival by applying an off-season stress on contrasting populations of the perennial grass Dactylis glomerata exhibiting a range of seasonal dormancy.2. Seventeen populations of D. glomerata, originating from a latitudinal gradient from Norway to Morocco, were subjected to three types of dehydration stress: winter frost in Norway, and summer drought and early spring (off-season) drought stress in the south of France. Growth rate and two leaf traits (leaf width and leaf dry matter content) suspected to be involved in the adaptation to dehydration stress were monitored under optimal conditions. We quantified plant dehydration survival as the amount of plant recovery after a severe stress.3. Nordic populations were found to be winter-dormant. Winter- and summer-dor-mant populations better survived frost and summer drought, respectively. However, no trade-off between growth potential and dehydration survival was detected in non-dormant plants in early spring when dehydration occurred unsea-sonably for all populations. Furthermore, Mediterranean populations better survived an early spring drought.4. Our results highlight the importance of assessing plant growth potential as a re-sponse to seasonal environmental cues. They suggest that growth potential and stress survival trade off when plants exhibit seasonal dormancy but can be func-tionally independent at other seasons. Consequently, the growth–stress survival relationship could be better described as a dynamic linkage rather than a constant and general trade-off. Moreover, leaf trait values, such as thinner and more ligni-fied leaves reflecting drought adaptation, may have contributed to the improved drought-stress survival without resulting in a cost to growth. 5. Further exploration of the growth–stress survival relationship should permit deci-phering the suite of plant traits and trait covariations involved in plants’ responses to increasing stress.

Sammendrag

Lengre vekstsesong og høyere temperaturer om høsten gir spørsmål om de anbefalte høstetidspunktene for eng fortsatt er gyldige og om ettervekst etter hovedslåtter bør høstes eller kan få stå. Vi har undersøkt effekt av tidspunkt for høsting og antall slåtter på mengde og kvalitet av etterveksten, og konsekvenser for overvintring og avling neste år av å enten la etterveksten stå, eller høste den med jevne mellomrom utover høsten mot vekstavslutning. I forsøk i eng dominert av timotei (Phleum pratense L.) på Holt (Tromsø), Løken (Øystre Slidre), samt flere steder i Troms og Finnmark har vi undersøkt ettervekst etter tidlig og sein 2. slått. På Kvithamar (Stjørdal) og Fureneset (Fjaler) har vi målt gjenvekst etter to eller tre slåtter i timoteidominert eng, samt gjenvekst etter 3. slått i flerårig raigras (Lolium perenne L.). Etterveksten er generelt lav sjøl om høsttemperaturene er blitt høyere. Dette skyldes antakelig svært lav lysinnstråling i høstmånedene, noe som forsterkes dess lengre nord en kommer. Fôrkvaliteten er god. Det hadde ingen negative konsekvenser å la etterveksten stå. Høsting av ettervekst bidro til mindre timotei det påfølgende året, spesielt i nord. I raigras hadde høsting av ettervekst negativ effekt både på avling i 1. slått og total avling det påfølgende året.

Sammendrag

NIBIO avdeling Fôr og husdyr har i samarbeid med NLR testa åtte ulike frøblandingar for kombinasjon sauebeiting og slått som del av Rettleiingsprøving. Felta var etablert i 2012 og 2013 på ti lokalitetar i sør-Norge og fire i nordlege eller høgareliggande område, og felta skulle etablerast slik at fleirårig raigras var på grensa til å klare overvintringa. Det var små skilnader mellom blandingane i total årsavling over engår, men store skilnader mellom felta. Dei artane som har klart seg best under ulike tilhøve har tatt over i blandingane. Det kan derfor vere rett å bruke allsidige frøblandingar slik at meir vintersterke artane kan ta over ved eventuelle vinterskadar.

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Sammendrag

A comprehensive set of Festulolium cultivars from on-going field trials in the Eucarpia network was characterised at the chromosome level using genomic in situ hybridization (GISH) and by Diversity Array Technology (DArT) markers. Both technologies were found to be complementary in describing the breeding history of the plant material. The genomic composition of the Lolium X Festuca cultivars varied from those that comprised equivalent proportions of their parental genomes to introgression lines where small chromosome segments of Festuca had been translocated onto Lolium chromosomes. The breadth of genotype combinations found within the grass cultivars described represents an important resource of genetic variations necessary to combat the diverse abiotic stresses encountered within Europe, including safeguards against prolonged exposure to harsh weather conditions. It is likely that in future plant breeding, genotyping will contribute to precision-transfers of targeted Festuca genes into Lolium germplasm in order to enhance resilience to climate change.

Sammendrag

Increasing abundance of Juncus effusus (soft rush) and Juncus conglomeratus (compact rush) in pastures and meadows in western Norway has caused reductions in forage yield and quality in recent decades. Understanding plant development and regrowth following cutting is essential in devising cost-effective means to control rushes. In a field experiment in western Norway, we investigated development of above- and below-ground fractions of rush from seedlings to three-year-old plants, including the impact on vigour of disturbing growth by different cutting frequencies during the period 2009–2012. Each year, the plants were exposed to one or two annual cuts or left untreated and five destructive samplings were performed from March to early December. Juncus effusus showed significantly more vigorous growth than Juncus conglomeratus in the last two years of the study period. The above-ground:below-ground biomass ratio of both species increased mainly in spring and early summer and was reduced in late summer and autumn. Removal of aerial shoots also reduced the below-ground fraction of both species. One annual cut in July effectively reduced biomass production in both species by 30–82%, which was only a slightly smaller reduction than with two annual cuts, in June and August. Mechanical control measures such as cutting can thus effectively reduce rush vigour when performed late in the growing season.

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Sammendrag

Climate change and its effects on grassland productivity vary across Europe. The Mediterranean and Nordic regions represent the opposite ends of a gradient of changes in temperature and precipitation patterns, with increasingly warmer and wetter winters in the north and increasingly warmer and drier summers in the south. Warming and elevated concentration of atmospheric CO2 may boost forage production in the Nordic region. Production in many Mediterranean areas is likely to become even more challenged by drought in the future, but elevated CO2 can to some extent alleviate drought limitation on photosynthesis and growth. In both regions, climate change will affect forage quality and lead to modifications of the annual productivity cycles, with an extended growing season in the Nordic region and a shift towards winter in the Mediterranean region. This will require adaptations in defoliation and fertilization strategies. The identity of species and mixtures with optimal performance is likely to shift somewhat in response to altered climate and management systems. It is argued that breeding of grassland species should aim to (i) improve plant strategies to cope with relevant abiotic stresses and (ii) optimize growth and phenology to new seasonal variation, and that plant diversity at all levels is a good adaptation strategy.

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Sammendrag

Norwegian cultivars and breeding materials of perennial ryegrass and Festulolium were planted at three locations in Denmark, France and Japan for test-ing of resistance against leaf diseases. In general, all plant materials were susceptible to crown rust. The highest incidence of rust attack occurred at the French site, which due to its climatic conditions might be the most suitable testing site for future scoring of similar plant material. Entries based on introgressed genetic materials from UK were most resistant towards crown rust. Crown rust resistance needs increased focus as a breeding objective in the Nordic region due to climate changes, which will most likely lead to increased infection of leaf diseases.

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Sammendrag

The effect of variable autumn temperatures in combination with decreasing irradiance and daylength on photosynthesis, growth cessation and freezing tolerance was investigated in northern- and southern-adapted populations of perennial ryegrass (Lolium perenne) and timothy (Phleum pratense) intended for use in regions at northern high latitudes. Plants were subjected to three different acclimation temperatures; 12, 6 and 9/3°C (day/night) for 4 weeks, followed by 1 week of cold acclimation at 2°C under natural light conditions. This experimental setup was repeated at three different periods during autumn with decreasing sums of irradiance and daylengths. Photoacclimation, leaf elongation and freezing tolerance were studied. The results showed that plants cold acclimated during the period with lowest irradiance and shortest day had lowest freezing tolerance, lowest photosynthetic activity, longest leaves and least biomass production. Higher acclimation temperature (12°C) resulted in lower freezing tolerance, lower photosynthetic activity, faster leaf elongation rate and higher biomass compared with the other temperatures. Photochemical mechanisms were predominant in photoacclimation. The northern-adapted populations had a better freezing tolerance than the southern-adapted except when grown during the late autumn period and at the highest temperature; then there were no differences between the populations. Our results indicate that the projected climate change in the north may reduce freezing tolerance in grasses as acclimation will take place at higher temperatures and shorter daylengths with lower irradiance.

Sammendrag

KORT OM KLIMAFRAMSKRIVNINGER I NORGE. Klimaet i Norge er i endring og klimaframskrivinger fram mot 2100 viser økende middeltemperatur og nedbør stort sett over hele Norge. Temperaturøkningen er forventet størst nord i landet og større om vinteren enn om sommeren. Årsnedbøren vil også øke mest i nord. I tillegg vil variasjonen i både temperatur og nedbør øke framover, og dette gir økt risiko for ekstremvær. Nedbørsendringen mellom årstider varierer mye mellom de ulike klimaframskrivningene...

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During the past two decades, significant spread of the perennial weeds Juncus effusus (soft rush) and Juncus conglomeratus (compact rush) in coastal parts of Norway seems to have coincided with an observed rise in winter temperatures. This study investigated the frost tolerance (LT50) and effects of moderate frost exposure on rush plant regrowth over time during the period late November to late winter/spring, and photosynthetic activity in late winter/spring. Juncus effusus and J. conglomeratus of physiologically young age (seedlings) displayed similar high frost tolerance (LT50) and did not differ significantly in regenerative ability following prolonged frost exposure. Regrowth capacity generally increased during winter and when stress conditions increased, shoot formation was prioritised over total biomass production. Maximum quantum efficiency of photosystem II (Fv/Fm) and performance index of photosystem II (PI) were high in late winter/spring, with J. effusus showing higher values than J. conglomeratus. Green, photosynthetically active shoots, which facilitate accumulation of carbohydrates during autumn and even in winter, may provide Juncus spp. with substantial competitiveness in late winter and spring. The results revealed that the dominance of J. effusus over J. conglomeratus in pastures and leys is not due to major differences in winter survival parameters, but probably the higher photosynthetic efficiency observed in J. effusus. Generally higher temperatures during winter and lower frost kill may be contributing to the current increase in rush infestation.

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Sammendrag

Climate change and its effects on grassland productivity vary across Europe. The Mediterranean and Nordic regions represent the opposite ends of a gradient of changes in temperature and precipitation patterns, with increasingly warmer and wetter winters in the north and increasingly warmer and drier summers in the south. Warming and elevated concentration of atmospheric CO2 may boost forage production in the Nordic region. Production in many Mediterranean areas is likely to become even more challenged by drought in the future, but elevated CO2 can to some extent alleviate drought limitation on photosynthesis and growth. In both regions, climate change will affect forage quality and lead to modifications of the annual productivity cycles, with an extended growing season in the Nordic region and a shift towards winter in the Mediterranean region. This will require adaptations in defoliation and fertilization strategies. The identity of species and mixtures with optimal performance is likely to shift somewhat in response to altered climate and management systems. It is argued that breeding of grassland species should aim to (i) improve plant strategies to cope with relevant abiotic stresses and (ii) optimize growth and phenology to new seasonal variation, and that plant diversity at all levels is a good adaptation strategy.

Sammendrag

Ei meir målretta utvikling av frøblandingar og sikrare utprøving av desse i Norge, kan gje auka engavlingar.

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Sammendrag

Lyssiv (Jûncus effûsus L.) og knappsiv (Jûncus conglomerâtus L.) har vorte eit svært synleg ugras dei siste tiåra. Auken har vore mest synleg i kystområda og litt innover i landet. Siv er lett synleg i ekstensivt driven eng og beite, og det er i aukande grad også eit problem i yngre eng i tilsynelatande god drift. Dette fagheftet er ei samling artiklar om siv som er publisert i Bondevennen frå oktober 2016 til juni 2017. Artiklane byggjer på resultat frå forskingsprosjektet “Siv – eit aukande ugrasproblem i eng og beite”. Landbruksdirektoratet har løyvt midlar til denne formidlingsdelen, som i tillegg til serien med fagartiklar omfatta markdagar og fagmøte. Prosjektet “Siv – eit aukande ugrasproblem i eng og beite” (2009-2015) hadde som mål å greia ut veksemåten til lyssiv og knappsiv for å finna målretta tiltak for å kontrollera den stadig aukande utbreiinga av siv på Vestlandet. Prosjektet skulle skaffa fram ny kunnskap om veksemåten til lyssiv og knappsiv som grunnlag for råd om mekaniske og kjemiske tiltak. I tillegg skulle ein sjå på korleis jordtilhøve og dreneringstilstand, agronomi og klimaendringar påverkar overleving og konkurransetilhøve. Prosjektet var finansiert av Norges Forskningsråd (Fondsmidlar forskingsavgift i landbruket), og FMLA i Rogaland, Hordaland, Sogn og Fjordane og Møre og Romsdal. Prosjektet var eit samarbeid mellom NIBIO med einingane NIBIO Fureneset og NIBIO Plantehelse, Norsk Landbruksrådgiving Rogaland, Norsk Landbruksrådgiving Vest og Norsk Sau og Geit. NIBIO var prosjekteigar. Medverkande i formidlingsprosjektet har vore fagfolk frå NIBIO Avd. Fôr og husdyr (Fureneset, Fjaler, Sogn og Fjordane) og Avd. Skadedyr og ugras (Ås, Akershus), Norsk Landbruksrådgiving Rogaland, Norsk Landbruksrådgiving Vest og NMBU, Fakultet for miljøvitenskap og naturforvaltning (Ås). Målet er at dette heftet, med ei samla oversikt over det me veit om siv i dag, gir grunnlag for praktiske tiltak i kampen mot siv i tradisjonell og økologisk drift. Kunnskapen gir også grunnlag for rettleiingsteneste og forvalting til å målretta råd og tiltak

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Global climate change and increased pressure for adopting more sustainable agricultural practices call for new approaches in breeding forage crops. In the cool temperate regions of Europe these crops may benefit from a warmer and prolonged growing season, but new stresses may emerge during autumn and winter, whereas further south risk of drought will increase. In addition, future forage crops have to use both nutrients and water more efficiently to maximize production per unit area. This paper presents examples of how perennial forage crops can be adapted to the projected European environmental conditions through breeding. In the Nordic region, the focus is on identifying traits that are important for high yields under changed overwintering conditions and management practices. In temperate maritime Europe, the breeding focus is on forage grass and legume root systems for ecosystem service, nutrient and water use, as well as the advantages and potential for Festulolium, including its role in ruminant nutrition. In temperate and southern Europe, breeders aim to develop varieties that can survive long drought periods and recover rapidly following autumn rains, as well as improving adapted legume species with the following aims: reducing use of synthetic fertilizers, mitigating the environmental impacts of ruminant production systems; and reducing their dependency on external protein-rich feeds. Forage production systems, which are commonly found in areas less suited to grain production, can contribute significantly to future food security but only if forage crops can be successfully adapted to meet future environmental challenges.

Sammendrag

Eight experiments with cultivars (cvs.) of grass and clover species were established in the Faroe Islands, Greenland, Iceland, Norway and Sweden to evaluate important forage species and cvs. in terms of yield potential, persistence and adaptation to variable climate in the West Nordic countries. Timothy had on average the highest spring cover after three years of trial together with smooth meadow grass (cv. Knut), whereas perennial ryegrass had the lowest spring cover after three years. On average cocksfoot (cv. Laban) and timothy (Grindstad related cvs.) gave the highest yield, 8.85 and 8.71 t ha-1, respectively, and smooth meadow grass and common bent grass the lower yields, 7.52 and 7.30 t ha-1, respectively. The results from these experiments show that we have a wide range of species and cultivars usable in the West Nordic areas. We can meet an increase in temperature to a certain level by moving the more southern species and cvs. farther north, however, our most winter hardy cvs. are still important to maintain.

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Ryegrass x fescue interspecific hybridization (so-called Festulolium) has great potential for forage diversification because of its many amphiploid and introgression-bred forms. Festulolium breeding efforts aim to improve adaptation to mainly winter cold and summer drought through higher abiotic stress tolerance. This goal must be met with a minimum of compromise regarding productivity in the first years of full exploitation. To compare field performances, a 21-entry trial of Festulolium and controls of pure species has been ongoing since 2012 in eight European countries. The yield data collected in 2012 and 2013 in nine locations showed that the Festulolium cultivars performed on average quite well compared to pure species controls. In amphiploids, the annual yield appeared to be mainly driven by the Lolium sp. parent combined with F. pratensis (Fp); the Lm x Fp amphiploids performed thus far better on average than the Lp x Fp equivalents. The only amphiploid from F. glaucescens included in the study had an intermediate response over locations, which was closer to tall fescue than to F. pratensis. Interestingly, a broad variability for yield among the Lm x Fp cultivars appeared to be associated with climate interactions when cold, wet locations were contrasted with more temperate locations with early spring growth.

Sammendrag

The current germplasm of forage crops like perennial ryegrass (Lolium perenne L.), timothy (Phleum pratense L.) and red clover (Trifolium pratense L.) are not adequately adapted to future climatic conditions at higher latitudes. The climate is predicted to be more unstable during winter, and winter survival needs to be improved. In this study, the aim was to detect the effects of selection/local adaptation by estimating genome-wide shifts in allelic composition of single nucleotide polymorphism markers in samples from swards of perennial ryegrass, timothy and red clover grown and managed at diverse locations in Norway. In addition separate mixtures of cultivars and breeding populations of perennial ryegrass, timothy and red clover was sown at five geographically distinct locations throughout Norway. The fields were harvested for 3 years and leaf tissues sampled randomly from about 200 plants field-1 year-1. To detect allelic shifts, genotyping by sequencing was used to generate genome-wide allele frequency fingerprints (GWAFFs). These allele frequency fingerprints were used to monitor shifts in population structure in response to location and years. Preliminary analyses demonstrate that the GWAFFs clearly distinguished samples from years/fields with good survival from those with poor survival based on scoring of winter survival in spring in perennial ryegrass and red clover.

Sammendrag

Lyssiv og knappsiv toler frost på linje med grasartane dei veks saman med i eng og beite. Under snøfrie forhold kan dei auka næringsreservane frå hausten gjennom vinteren og til våren. Denne evna til å ha fotosyntese heile året, og dermed kunna lagra næringsreservar i ein periode der grasartene held vinterkvile, gir lyssiv og knappsiv eit stort konkurransefortrinn når våren kjem. Evna til å akkumulera karbohydratreservar heile året verkar viktigare for den invaderande sivveksten enn mindre skilnader i frosttoleranse mellom lyssiv og knappsiv.

Sammendrag

Lyssiv og knappsiv har minst næringsreservar på seinsommaren, og mekaniske tiltak bør setjast inn frå dette tidspunktet og ut vekstsesongen. Beitepussar er greitt der ein har store areal som ein kan koma til med beitepussar, men nedste delen av stengelen blir ståande att og gir plantene gode sjansar for vidare vekst. Der det er overkomeleg med planter, er ryddesag enno meir effektivt, fordi ein kan knusa jordstengelen og dermed øydeleggja planta fullstendig.

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Sammendrag

I denne rapporten er det gjeve ei vurdering av kva framskriving av klimaendringane med auka nedbør og temperatur kan få å seia for landbruket på Vestlandet. Det er lagt hovudvekt på å omtala situasjonen for grovfôrdyrking då det saman med grovfôrbasert husdyrhald er tyngde-punktet i vestnorsk landbruk. Betring av dreneringstilstand er viktig då meir nedbør og moderne jordbruksdrift set større krav til dreneringstilstanden.Dreneringstilstand verkar sterkt inn på arealproduktiviteten.Ved-likehald av jordkapitalen har vore for lite vektlagt over tid, og det er eit etterslep som må takast att. Overvintring av engvokstrar er vist til både som viktig utfordring i dag sett i samanheng med klima og driftsmåte, og at det er ei utfordring å skaffa klimatilpassa plantemateriale framover. Gjødslingspraksis må både ut frå agronomiske- og miljømessige grunnar leggjast opp slik at ein unngår spreiing av husdyrgjødsel seint i veksetida, for å auka N- og P-utnyttinga og redusera tap til vatn og luft. Dette vil innebera at ein del må utvida lagerkapasiteten for husdyrgjødsel. Frukt og bærproduksjon er svært klimaavhengig. Auka frekvens av vind vert vurdert som utfordrande, ikkje minst økonomisk. Meir nedbør er utfordrande m.o.t. meir sjukdom og bakteriosar. Sterk vind, kombinert med vassmetta jord, fører til meir vindfall i skog. Dette er økonomisk, fagleg og i ressurssamanheng utfordrande for ei ung næring. Auka nedbørsmengde og nedbørintensitet er tilhøve som gjer at fare for flaum og skred må vurderast grundigare i ulike samanhengar, noko som vedkjem landbruket m.o.t. dimensjonering av drenering, avlaup, stikkrenner og sikring mot graving og erosjon. Verksemd som skogsvegbygging må ta meir omsyn til auka vassføring, og med fare for erosjon, flaum og skred. Det å dimensjonera for auka vassføring og førebyggja mot flaum og skred, gjeld og for andre samfunnssektorar.

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The expected temperature rise in late summer/early autumn can change the conditions for acclimation and affect the winter survival of perennial crops. This study examined the effect of the temperature just before the onset of cold acclimation (pre-acclimation) on freezing tolerance of timothy (Phleum pratense L.), perennial ryegrass (Lolium perenne L.) and red clover (Trifolium pratense L.) populations (both cultivars and breeding populations) adapted to either northern or southern parts of Norway. Using phytotron experiments, we studied whether increasing pre-acclimation temperature delays growth cessation, affects photoacclimation and reduces freezing tolerance. Furthermore, we assessed whether these effects were related to the latitudinal adaptation of the plant material. The results showed that a rise in pre-acclimation temperature decreased both cold acclimation capacity and photoacclimation in these species. This affected the freezing tolerance, which was reduced significantly more in northern-adapted population of timothy and perennial ryegrass compared with southern-adapted populations. Red clover was less affected by temperature changes than the grasses.

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This study compared the forage quality of Festulolium entries of festucoid (Hykor) and loloid attributes (Felopa and Norwegian candivars) with major cultivars of the parent species perennial ryegrass and meadow fescue, and with timothy. Forage NDF, iNDF, kdNDF and DDM were analysed at vegetative stage, early heading, heading and anthesis during spring growth (SG) and two subsequent regrowths over two production years at two locations in Norway. NDF and iNDF increased and kdNDF and DDM decreased with advancing maturity, mostly expressed in SG, with negative correlations between DDM and NDF and iNDF and ADL and strong positive correlations with kdNDF. In SG, across years and locations, the content of NDF at heading stage was 30% higher and iNDF 400% higher in stems than in leaves, while stem kdNDF was about 50% of that in leaves. In general, timothy cv. Grindstad and Festulolium cv. Hykor had the highest NDF and iNDF and the lowest kdNDF values. Loloid entries of Festulolium were quite similar to perennial ryegrass, although the tetraploid entry proved better than the others with respect to forage quality. Regarding nutritive value, the festucoid and loloid types of Festulolium should be considered separate groups. The effect of year was more pronounced than that of location, for which the ranking of entries was quite similar. Loloid Festulolium is prone to winter damage and, although it has higher nutritive value than the parent species, its use will depend on the conditions for winter survival.

Sammendrag

Med auka fokus på grovfôrkvalitet og ein lengre vekstsesong, er ei godt drenert jord viktig for at bonden raskast råd kan koma ut på jordet, både om våren for jordarbeiding og gjødsling og for å hausta i vekstsesongen.

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Sammendrag

The potential of ×Festulolium as a forage species for Nordic conditions was investigated by comparing Norwegian candivars (LpFp-T, LmFp-T, LpFp-D-N, LpFp-D-UK) differing in parental origin and ploidy level with commercial cultivars of ×Festulolium (Hykor, Felopa), the parental species perennial ryegrass (Lolium perenne L.) and meadow fescue (Festuca pratensis L.), and timothy (Phleum pratense L.). Plant development was observed as leaf:stem ratio and standardised development stage, and dry matter yield and digestibility were studied throughout two consecutive harvest seasons (2007 and 2008) as an effect of taking the first cut at four maturity stages, namely: 1) vegetative growth, 2) early heading), 3) heading and 4) anthesis, and then consecutive cuts throughout the season. Observations were made at two locations in Norway (61°N, 67°N). Leaf:stem ratio and standardised development stage were affected by maturity stage, and the loloid types of ×Festulolium (Felopa and the candivars) grouped between the parental species as to developmental pattern. The most extreme changes across maturity stages 1-4 in first cut were seen in the festucoid type Hykor (smallest) and in timothy (largest). Across maturity stages 2 and 3, for two years Hykor obtained higher dry matter yield than the other entries, but overall digestible dry matter yield was equal in Hykor and LpFp-T due to the better digestibility in LpFp-T. The lower dry matter yield obtained in ×Festulolium Felopa, the diploid candivars and LmFp-T was mainly due to winter damages. Consistency was found between the locations for the entries investigated. For Nordic growing conditions, in which winter hardiness is required for commercial cultivars, the amphitetraploid breeding approach of perennial ryegrass and meadow fescue should be pursued. It is the parental origin of the candivar LpFp-T, which was comparable to Hykor, the best of the commercial ×Festulolium cultivars, and performed better than the cultivars of the parental species.

Sammendrag

Overvintring i eng vert bestemt av klimaet, jorda og dreneringstilstanden på veksestaden, og plantene si genetiske tilpassing til klimaet. Overvintringsevna vert også påverka av drifta, m.a. nitrogengjødsling, tal slåttar og tidspunkt for slått, stubbehøgde og jordpakking.

Sammendrag

Scenarios of climate changes indicate longer and more frequent spells of mild weather during winter in northern latitudes. De-hardening in perennial grasses could increase the risk of frost kill. In this study, the resistance to de-hardening of different grass species and cultivars was examined, and whether the resistance changes during winter or between years, was tested. In Experiment 1, two cultivars of timothy (Phleum pratense L.) and perennial ryegrass (Lolium perenne L.) of contrasting winter hardiness were grown under ambient winter conditions, transferred from the field in January and April 2006 to the laboratory for 9 d with controlled de-hardening conditions of 3°C, 9°C and 15°C. The timothy cultivars were tested at 3°C, 6°C and 9°C in a similar experiment (Experiment 2) in January 2007. De-hardening, measured as decrease in frost tolerance (LT50), was less in timothy than in perennial ryegrass and increased with increasing temperatures. The northern winter-hardy cultivar Engmo of timothy de-hardened more rapidly than the less-hardy cultivar Grindstad, but had higher initial frost tolerance in both experiments, whereas there was less difference between cultivars of perennial ryegrass in Experiment 1. Cultivar Grindstad of timothy lost all hardiness in early spring at all temperatures, whereas cultivar Engmo maintained some hardiness at 3°C. Cultivar Engmo de-hardened at a lower rate in 2007 than in 2006, in spite of similar frost tolerance at the start of de-hardening treatment in both years. This indicates that the rate of de-hardening was controlled by factors additional to the initial frost tolerance and that autumn weather conditions might be important for the resistance to de-hardening.

Sammendrag

Scenarios of climate changes indicate longer and more frequent spells of mild weather during winter in northern latitudes. De-hardening in perennial grasses could increase the risk of frost kill. In this study, the resistance to de-hardening of different grass species and cultivars was examined, and whether the resistance changes during winter or between years, was tested. In Experiment 1, two cultivars of timothy (Phleum pratense L.) and perennial ryegrass (Lolium perenne L.) of contrasting winter hardiness were grown under ambient winter conditions, transferred from the field in January and April 2006 to the laboratory for 9 d with controlled de-hardening conditions of 3°C, 9°C and 15°C. The timothy cultivars were tested at 3°C, 6°C and 9°C in a similar experiment (Experiment 2) in January 2007. De-hardening, measured as decrease in frost tolerance (LT50), was less in timothy than in perennial ryegrass and increased with increasing temperatures. The northern winter-hardy cultivar Engmo of timothy de-hardened more rapidly than the less-hardy cultivar Grindstad, but had higher initial frost tolerance in both experiments, whereas there was less difference between cultivars of perennial ryegrass in Experiment 1. Cultivar Grindstad of timothy lost all hardiness in early spring at all temperatures, whereas cultivar Engmo maintained some hardiness at 3°C. Cultivar Engmo de-hardened at a lower rate in 2007 than in 2006, in spite of similar frost tolerance at the start of de-hardening treatment in both years. This indicates that the rate of de-hardening was controlled by factors additional to the initial frost tolerance and that autumn weather conditions might be important for the resistance to de-hardening.

Sammendrag

Forsøk og erfaring har hittil vist at raisvingel har stort avlingspotensial. Godkjent på norsk sortsliste er sortane Paulita og Felina. ’Hykor’, med same foreldreartar som ’Felina’, er tilrådd godkjent etter verdiprøving. Nye forsøk viser at fleire kandidatsortar frå norsk sortsutvikling kan vera både varige, gi høg avling og ha god fôrkvalitet.

Sammendrag

Klimaet er i rask endring. Konsekvenser for grasproduksjon i 2071-2100 er inntil tre måneder lengre vekstsesong, med mulighet for å øke antallet høstinger og/eller forlenge beitesesongen i tilsvarende grad. Risikoen for frostskader om høsten/vinteren og isdekkeskader vil minke de fleste steder i følge modellberegninger for seks steder, mens risikoen for frostskader etter vekststart vil øke noe enkelte steder langs kysten.

Sammendrag

Lyssiv og knappsiv er to problemugras som har fått auka utbreiing i kystnære strok på Vestlandet. For å vinne ny kunnskap om svake og sterke sider hos sivartane og koma fram til situasjonstilpassa tiltak mot dei, startar Bioforsk Vest Fureneset og Bioforsk Plantehelse i samarbeid med saueavlslaga, fylkesmannen og forsøksringane i regionen, eit prosjekt der målet er å finne kostnadseffektive metodar for kontroll av ugrasa.

Sammendrag

Vassoverskot om hausten og vinteren har i forsøk ikkje gitt eintydig negativ effekt på frosttoleranse i timotei og engelsk raigras. Dette betyr at risikoen for at meir regn skal svekke overvintringa kan vere mindre enn venta. Temperatur er truleg ein viktig tilleggsfaktor både om hausten, der planter ved høg temperatur vil trengje vatn, eller om vinteren der høg temperatur og vassoverskot kan hemme omsetninga og dermed svekke plantene.

Sammendrag

I eit forsøk med ulik såtid med timotei og fleirårig raigras, hadde timotei større rotdanningskapasitet samanlikna med fleirårig raigras om vinteren og våren. Evna til rotdanning var påverka av såtid, og sein såing (juli) gav betre rotgjenvekst neste vår samanlikna med tidleg sådde (mai) planter når plantene vart utsette for moderat frosteksponering. Karbohydratmengda auka gjennom vinteren.

Sammendrag

I et omfattende klimaprosjekt i Bioforsk undersøker vi effekten av ulike faktorer på overvintringsskader, samt frost- og istoleranse i gras. Temperatur er sannsynligvis den viktigste enkeltfaktoren, mens økning i CO2-innhold og nedbørsmengde betyr mindre. Mildvær midtvinters vil gi raskere avherding, og store fluktuasjoner i været kan gi økning i isskader enkelte steder.

Sammendrag

Jordart og vérlag har svært mykje å seia for kor godt vilkåra ligg til rette for økologisk engdyrking. Jordarten er avgjerande både for jordfysiske- og jordkjemiske tilhøve, og såleis også for korleis ein maktar å halda oppe næringsforsyninga og avlingsnivået over tid. Eit godt innslag av kløver i enga er viktig for avlingsnivået og avlingskvaliteten ved økologisk drift. Det er difor viktig å få etablert ei eng med stor del kløver i attleggsåret, og å halda oppe ein høg andel kløver utover i engåra.