Vedlegg

CV

Biografi

Forskningsområder:

  • Gress til grøntanlegg
  • Integrert plantevern med fokus på myntflekk og mikrodochium flekk
  • Vinterstyrke
  • Abiotiske stressfaktorer (is, vann, temperatur)
  • Etablering, reetablering og skjøtsel av gress til grøntanlegg

Tjenester:

  • Diagnose av sykdommer på gress

Utdanning:

PhD in Agricultural Sciences at National Academy of Sciences of Belarus (2004) and in Plant Pathology at Norwegian University of Life Sciences, UMB (2011).

Les mer
Til dokument

Sammendrag

Seed mixtures with a nurse grass that germinates quickly at low soil temperatures can be an option for faster establishment of Agrostis stolonifera (AS) putting greens after winter damage. From 2015 to 2018 Poa trivialis (PT) ‘Dark Horse’ and Lolium perenne (LP) ‘Chardin’ were evaluated as nurse grasses in comparison with pure AS ‘Independence’ at two experimental sites in each of the two major climatic zones of the Nordic countries. Poa annua (PA) ‘Two‐Putt’ was also included as a nurse grass in the northern zone. As an overall trend, establishment was faster with AS+LP than with AS+PT and AS+PA, which in turn had faster establishment than pure AS. In the northern zone, AS+PT produced better turf quality than pure AS in the seeding year and year after and tended to be superior even on average for the entire trial period (mean value 6.0 vs. 5.8 for pure AS, 5.3 for AS+LP, and 4.6 for AS+PA; scale 1–9 where 9 is the highest quality). In the same zone, AS+PT also suffered less overall winter damage than the other combinations and was less infected with microdochium patch than pure AS. In the southern zone, PT and especially LP were far more persistent than in the northern zone and compromised turfgrass quality compared with pure AS. In conclusion, we recommend PT as a nurse grass for faster establishment of AS putting in the northern zone, but not in the southern zone where AS should rather be seeded in a pure stand.

Til dokument

Sammendrag

Dollar spot was officially documented in Scandinavia in 2013 and the spread and damage from this disease has increased during last years. In summer 2017, on the golf greens with red fescue (Vallda GC, Sweden) and with the mixture of red fescue, colonial bentgrass and annual bluegrass (Roskilde GC, Denmark) rolling 2 times per week reduced dollar spot 61% and 37% and rolling 4 times per week reduced dollar spot 95% and 54%, respectively. Thus, rolling 3-4 times per week can be recommended on golf greens with dollar spot pressure. In the experiment 2018 dollar spot was reduced 24% with increase in nitrogen from 150 to 240 kg ha-1 yr-1 on creeping bentgrass/annual bluegrass golf green (Kävlinge GK, Sweden). However, the increased N-rate lead to a higher degree Microdochium patch from 14% to 30%.

Sammendrag

This is a report on the potential of NanoPro™ to reduce the rate of two commonly used fungicides for control of Microdochium patch (Microdochium nivale), the economically most important turfgrass disease in Scandinavia. The experiment was conducted from 14 Sept. 2018 to 1 May 2019 on an annual bluegrass golf green at the NIBIO Turfgrass Research Center Landvik. Use of NanoPro™ at a rate of 292 ml/ha in tank mixture with the systemic fungicide Delaro® SC 325 or/and the contact fungicide Medallion® TL produced the same level of disease control with a 30-60% reduction in fungicide dosage as with full fungicide dosage without additive. NanoPro™ was more effective with Medallion® TL than with Delaro® SC 325. We conclude that NanoPro™ may have a big potential in Scandinavia and other countries where authorities require reduced fungicide use. The experiment should be repeated one more year before giving final recommendations.

Sammendrag

Dette er den første rapporten om potensialet for additivet NanoPro til å redusere doseringen av de to mest brukte fungicider for bekjemping av mikrodochium flekk (Microdochium nivale), den økonomisk viktigste sykdommen på golfbaner i Skandinavia. Forsøket ble gjennomført fra 14.sept. 2018 til 1.mai 2019 på en tunrappgreen ved NIBIO Turfgrass Research Centre Landvik. Bruk av NanoPro 292 ml/ha i tankblanding, først med det systemiske fungicidet Delaro® SC 325 den 19.sept.18 og deretter med kontakt fungicidet Medallion® TL den 15.nov.18 gjorde det mulig å oppnå samme sykdomskontoll med 30-60 % mindre dose av fungicid. Virkningen av NanoPro var bedre med Medallion® TL enn med Delaro® SC 325. Våre foreløpige data tyder på at NanoPro kan være et viktig hjelpemiddel for å redusere forbruket av soppmidler på golfbaner. Forsøket bør gjentas ett år for å dokumentere effekten av NanoPro igjennom en artikkel i et vitenskapelig tidsskrift.

Til dokument

Sammendrag

Dollar spot is a destructive and widespread disease affecting most turfgrass species, but until recently it has been absent from the Scandinavian countries of northern Europe. In the fall of 2014, disease symptoms consistent with dollar spot were observed on a golf course fairway in Sweden. A fungus was isolated from symptomatic turf and identified as Sclerotinia homoeocarpa on the basis of ribosomal deoxyribonucleic acid (rDNA) internal transcribed spacer (ITS) sequences, morphology, and culture characteristics. The ITS sequence was identical to isolates of S. homoeocarpa from the eastern and midwestern United States. Koch’s postulates were fulfilled, confirming the S. homoeocarpa isolate as the causal agent. This is the first report of turfgrass dollar spot in Sweden and only the second report of the disease from Scandinavia. Because pesticides are rarely used in the cultivation of Scandinavian turfgrass, dollar spot disease may prove difficult to control through conventional means and potentially represents a major threat to the industry.

Sammendrag

Ice encasement (IE) is the most economically important winter stress in Scandinavia; however, little is known about the IE tolerance of different turfgrass species and subspecies except that creeping bentgrass (Agrostis stolonifera L.) is more tolerant than annual bluegrass (Poa annua L.). The objective of this study was to assess the impact of IE and two protective covers (plastic and plastic over a 10-mm woven mat) on the winter survival of six cool-season turfgrasses commonly used on golf greens. The experiment was conducted on a sand-based green at Apelsvoll, Norway (60°42′ N, 10°51′ E) during the winters of 2011–2012 and 2012–2013. Turfgrass samples (8 cm in diameter, 10 cm deep) were removed from the plots at the time of cover installation and throughout the winter. The samples were potted and percent live turfgrass cover assessed after 21 d of regrowth in a growth chamber. Percent turfgrass cover, percent disease, and turfgrass quality were also registered in the field plots in spring. Results indicated that velvet bentgrass (Agrostis canina L.) had superior tolerance to IE, surviving for 98 and 119 d of IE during the winters of 2011–2012 and 2012–2013, respectively. The order of IE tolerance in 2012–2013 was: velvet bentgrass > creeping bentgrass > Chewing’s fescue (Festuca. rubra L. ssp. commutata), slender creeping red fescue (F. rubra L. ssp. litoralis) ≥ colonial bentgrass (A. capillaris) > annual bluegrass. Colonial bentgrass responded negatively to both protective covers in 2012 due to the development of Microdocium nivale. None of the species benefited from the plastic cover alone, compared with natural snow conditions. Annual bluegrass was the only species that benefited from plastic over a woven mat.

Sammendrag

Ice encasement (IE) is the most economically important winter stress in Scandinavia; however, little is known about the IE tolerance of different turfgrass species and subspecies except that creeping bentgrass (Agrostis stolonifera L.) is more tolerant than annual bluegrass (Poa annua L.). The objective of this study was to assess the impact of IE and two protective covers (plastic and plastic over a 10-mm woven mat) on the winter survival of six cool-season turfgrasses commonly used on golf greens. The experiment was conducted on a sand-based green at Apelsvoll, Norway (60°42′ N, 10°51′ E) during the winters of 2011–2012 and 2012–2013. Turfgrass samples (8 cm in diameter, 10 cm deep) were removed from the plots at the time of cover installation and throughout the winter. The samples were potted and percent live turfgrass cover assessed after 21 d of regrowth in a growth chamber. Percent turfgrass cover, percent disease, and turfgrass quality were also registered in the field plots in spring. Results indicated that velvet bentgrass (Agrostis canina L.) had superior tolerance to IE, surviving for 98 and 119 d of IE during the winters of 2011–2012 and 2012–2013, respectively. The order of IE tolerance in 2012–2013 was: velvet bentgrass > creeping bentgrass > Chewing’s fescue (Festuca. rubra L. ssp. commutata), slender creeping red fescue (F. rubra L. ssp. litoralis) ≥ colonial bentgrass (A. capillaris) > annual bluegrass. Colonial bentgrass responded negatively to both protective covers in 2012 due to the development of Microdocium nivale. None of the species benefited from the plastic cover alone, compared with natural snow conditions. Annual bluegrass was the only species that benefited from plastic over a woven mat.

Til dokument

Sammendrag

There has long been a claim that winter injuries of grass are a significant economic burden for golf courses in the Nordic countries. To confirm this claim, in 2015 the Norwegian Institute of Bioeconomy Research and the Norwegian Golf Federation, with support of the Scandinavian Turfgrass and Environment Research Foundation, conducted a net-based survey about winter injury in the five Nordic countries (Denmark, Finland, Iceland, Norway, and Sweden). This comprehensive survey showed that total costs of repair of winter-injured greens and fairways together with lost revenue on golf courses in the Nordic countries can be at least €14 million. In a year with significant winter injuries, the average cost to repair the turf was between €3000 and €12,000 on 88% of the courses. The revenue loss after a winter with considerable injuries was less than €6000 at 50% of the courses, and 25% of the courses reported a loss between €6000 and €12,000 for these years. The causes of winter injuries varied depending on geography and grass species used on the greens. Biotic factors played a major role in the southern part of Scandinavia, and ice and water injuries were most devastating north of 60°N. This paper summarizes some of the answers from the respondents, including information about the dominating grass species on Nordic golf greens.

Sammendrag

Microdochium nivale (Fries) Samuels & Hallett is an important turfgrass pathogen on golf courses. Our objective was to evaluate Gliocladium catenulatum Gilman & Abbott and/or Streptomyces species for biological control of M. nivale on golf greens. The microbial agents were tested relative to fungicides and an untreated control in vitro and in five field trials from 2011 to 2014. G. catenulatum (Turf G+/WPG, Verdera OY, Finland) was applied from October to December and in March–April, while Streptomyces species (Turf S+/WPS, same manufacturer) was applied from May to October, both at four week intervals. In vitro, Streptomyces species suppressed the growth of M. nivale at 6 and 16°C, while G. catenulatum suppressed growth of M. nivale at 16°C only. In contrast, neither product, nor their combination, had any consistent effect in the field trials. A statistically significant reduction in Microdochium patch (from 3 to 2% of plot area) was seen in a trial on a green dominated by Festuca rubra L., but this reduction was deemed to be of little practical interest to the greenkeeper. Despite multiple applications over 3 yr to build up an antagonistic microflora, only fungicides reduced M. nivale significantly on greens dominated by Poa annua L. or Agrostis capillaris L., which generally had more disease. In conclusion, this research showed no potential of G. catenulatum or Streptomyces species to replace fungicides for control of M. nivale on northern-latitude golf greens.

Til dokument

Sammendrag

Red fescue (RF, Festuca rubra L.) is used on golf putting greens in the Nordic region due to its high disease resistance and low requirements for nitrogen (N) and water, but low density and growth rate makes RF susceptible to annual bluegrass (AB, Poa annua L.) invasion. Putting greens seeded with RF + bentgrass (Agrostis sp.) may be more competitive with AB but also have different playing characteristics. Our objective was to compare RF, RF + colonial bentgrass (CB, Agrostis capillaris L.), and RF + velvet bentgrass (VB, Agrostis canina L.) putting greens at two mowing heights (4.0 or 5.5 mm), three N rates (5, 10, or 15 g N m−2 yr−1), and three phosphorus (P)–arbuscular mycorrhizal fungi treatments (0 and 1.8 g P m−2yr−1 without inoculation and 0 g P m−2yr−1 with inoculation). The four-factorial experiment was conducted in 2011 and 2012 at Landvik, Norway. Red fescue provided lower visual quality and density and less competition against AB than RF + bentgrass combinations. Increasing the N rate from 5 to 15 g N m−2yr−1 increased the proportion of bentgrass tillers from 53 to 64% in RF + CB and from 86 to 92% in RF + VB. Surface hardness increased in the order RF + VB < RF + CB < RF turfs. Ballroll distance decreased with increasing N rate and was longer with RF and RF + VB than with RF + CB. The main effects of N and mowing height on AB invasion were not significant, but lower mowing increased AB competition in RF. Mycorrhiza colonization of roots was not significantly affected by any practice, and neither P nor arbuscular mycorrhizal fungi influenced the competition against AB.

Til dokument

Sammendrag

This report presents results from a project testing Turf G+/WPG (fungal products containing Gliocladium catenulatum) and Turf S+/WPS (bacterial products containing Streptomyces spp.), both from Interagro BIOS AB, and Vacciplant (seaweed product containing laminarine) from Nordisk Alkali AB, for the control of Microdochium nivale and other diseases on golf greens. Five field trials were carried out in Denmark, Sweden and Norway from October 2011 to September 2014, and Turf G+/WPG and Turf S+ were tested also in vitro. None of the test-products gave any consistent disease control in the field trials. A significant reduction in Microdochium nivale from 3 % of plot area on untreated plots to 2 % on treated plots was seen in one trial, but this was considered to be of little practical relevance. In all other trials with more severe attacks of Microdochium nivale, only the fungicide control treatment showed a significant reduction in disease compared with the untreated control. On average for all field trials over three years, the higher rate of Vacciplant, the combination of Turf G+/WPG and Turf S+/WPS, and the fungicide treatment gave, in turn, 22, 24 and 87 % less microdochium patch in the fall, but among these, only the effect of fungicide was significant. The effects of the biological products on pink or gray (Typhula incarnata) snow mold after snow melt were even smaller. In the in vitro trials, Turf S+ provided good control of Microdochium nivale at 6 and 16 ̊C, but Turf G+/WPG was effective only at the higher temperature. However, since these results could not be repeated under field conditions, we have to conclude that none of the test products represent any real alternative to fungicides for control of M. nivale or other diseases on Scandinavian golf courses.

Sammendrag

Syngenta’s GREENCAST model was used to predict timing of fungicide application against microdochium patch and pink snow mold caused by Microdochium nivale on an experimental golf green with annual bluegrass (Poa annua) at Bioforsk Landvik, Southern Norway from 5 Oct. 2012 until 1 June 2013. From 5 Oct. until snow covered the green on 2 Dec. 2012, application of the fungicides Headway (azoxystrobin + propiconazole) or Medallion (fludioxonil) only at GREENCAST high risk warnings resulted in equal control of microdohium patch with one less fungicide application than prophylactic application every third week, application at first sign of disease or application at GREENCAST medium risk warnings. The consequences for pinks snow mold in spring could not be evaluated as the turf was killed by the combination of ice encasement and low freezing temperatures during winter.

Til dokument

Sammendrag

This progress report presents preliminary results from a project providing data for potential registration of Turf S+ (bacterial product containing Streptomyces) and Turf G+/WPG (fungal product containing Gliocladium catenulatum), both from Interagro BIOS AB, and Vacciplant (seaweed product containing laminarine) from Nordisk Alkali AB, for the control of Microdochium nivale and other diseases on golf greens. Field trials with all three products are carried out on greens in Denmark, Sweden and Norway from 2011 to 2014, and Turf S+ og Turf G+/WPG are also tested in vitro. Half way through the project, none of the test-products have shown any consistent control of M. nivale or any other disease. In the trials at Bioforsk Landvik and Arendal GK, Norway, there was little attack of M. nivale and no significant effect of any treatment, while in the trials at Rungsted GC, Denmark and Kävlinge GC, Sweden, there were massive attacks, but a significant reduction in disease only in the fungicide control treatments. The fifth trial, at Sydsjælland GC, Denmark, had more healthy turf just before snow cover in late November 2012 on plots that had been sprayed the test products, especially with Turf S+ or Vacciplant than on unsprayed control plots, although the turf quality was not as good as in the fungicide control treatment. The first in vitro trial with the microbial agents suggested better effect of both G. catenulatum and Streptomyces sp. on M. nivale at 16 than at 6°C. Possible implications of this for the protocol will be discussed with the manufacturer. The experimental work continues until the summer of 2014.

Sammendrag

Gresset i grøntanlegg skades av soppsykdommer og invaderes av ugras. EU har bestemt at integrert plantevern (IPM) skal legges til grunn ved bekjempelse av skadegjørere. Det betyr økte krav til kunnskap og dokumentasjon fordi alternativer til kjemisk bekjempelse må vurderes og anvendes når de er effektive og økonomisk forsvarlige. Definisjon av skadeterskler og overvåking av sykdommer blir en utfordring.

Sammendrag

The use of velvet bentgrass (Agrostis canina L.) on putting greens is limited by sparse knowledge on optimal maintenance. Our objective was to determine the effects of N (75 or 150 kg N ha–1 yr–1), topdressing (0.5 or 1.0 mm biweekly), and mechanical-biological treatment (grooming, vertical cutting, spiking, and Thatch-less) on turfgrass visual quality, playability, winter survival, and thatch formation. The study was conducted at a coastal location in Norway (Landvik, 58°N) from August 2007 to May 2010 on sandbased root zone (United States Golf Association specifications) seeded in late spring 2007 with velvet bentgrass ‘Legendary’. Only the higher N rate gave acceptable quality during the first 2 yr after sowing. The higher N rate reduced moss and winter injuries from disease compared with the lower Nbut decreased surface hardness by 21% and reduced ball roll distance by 6 to 14%. Significant interactions reflected an increase in mat organic matter with increasing N rate under light but not under heavy topdressing. Compared with grooming only, grooming plus vertical cutting significantly reduced mat organic matter from 64 to 53 g kg–1. Grooming plus spiking improved water infiltrationrate by 51% compared with grooming alone. Thatch-less increased hardness of the otherwise soft plots receiving grooming plus spiking but had no effect on mat depth or organic matter content.

Sammendrag

 Winter injury of temperate grasses used for turf is a significant problem in northern climatic regions. Field trials at two locations in Norway previously demonstrated differences in winter survival between two Agrostis species, velvet bentgrass (Agrostis canina L.) and creeping bentgrass (Agrostis stoloniferaL.). The freezing tolerance is an important component of winter hardiness of turfgrasses and it was studied under controlled environments. We also determined the crown carbohydrate and protein changes at different stages of cold acclimation of velvet bentgrass and creeping bentgrass and assessed their relationship to freezing tolerance. Similar freezing tolerance in velvet bentgrass and creeping bentgrass was associated with similar levels of sucrose in crown tissue of acclimated plants. Significantly higher crown fructan content in creeping bentgrass than in velvet bentgrass had no significantimpact on LT50 and suggested negligible direct contribution of fructans to freezing tolerance. Increased freezing tolerance in response to cold acclimation was associated with enhanced amino acid synthesis, since serine hydroxymethyltrasfernse and methionine synthase were up-regulated by acclimation. The first acclimation stage caused more changes in the crown protein composition than subzero cclimation. 

Sammendrag

Foredraget tar utgangspunkt i IPM - "Intelligent Plant Management" / "Integrated Pest Mangement" og diskuterer hvilke tiltak greenkeeperer og banemestre kan skjøtte sine arealer med minst mulig bruk av plantevernmidler. Overskriftene er: ¨ 1. Man må kjenne sine fiender: De viktigste ugras og sjukdommer i sportgress 2. Rett art og sort 3. En sterk grasplante har lagringsreserver og deler karbohydrater med sine underjordiske venner. 4. Røtter trenger luft 5. Optimal gjødsling

Til dokument

Sammendrag

Field trials at two locations in Norway previously demonstrated differences in winter survival between two Agrostis species used for turf, velvet bentgrass (VB; A. canina L.) and creeping bentgrass (CB; A. stolonifera L.). The objectives of this study were to compare freezing tolerance and crowncarbohydrate composition of VB and CB. We also compared a direct and two indirect methods of measurements of freezing tolerance. Treatments consisted of: (i) nonacclimated (NA); (ii) acclimation at 2°C for 2 wk (A2); (iii) acclimation at 2°C for 4 wk (A4); and (iv) acclimation at 2°C for 4 wk plussubzero acclimation at –2°C for 2 wk (A4+SZA2). Crowns were harvested for determination of carbohydrates and freezing tolerance. Freezing tolerance (lethal temperature for 50% of the test population [LT50]) was based on whole plant survival (WPS), 2,3,5-triphenyltetrazolium chloride (TTC)reduction, and electrolyte leakage (EL). There were no significant difference in freezing tolerance between VB and CB. The LT50 based on WPS was significantly lower for plants exposed to A2 (–12.7°C), A4 (–14.5°C), and A4+SZA2 (–14.6°C) compared to the NA control treatment (–8.4°C). The concentrations of fructans and sucrose were significantly higher in A2 compared to NA plants of both species, but only fructans continued to increase at A4. The LT50 based on TTC reduction showed better correlation with LT50 based on WPS compared to LT50 values based on EL.

Sammendrag

Del II handler om vinterstyrke hos hundekvein (blant annet frosttoleranse, toleranse for oksygenmangel og mottagelighet for rosa snømugg (Microdochium nivale).

Sammendrag

  Mycket thatch ger mindre hälsosamma gräsmattor. Mängden thatch är ett resultat av två paralella processer  bildande av växtmassa och nedbrytning av dött organiskt material. Plantans växt stimuleras av gödning och bevattning. Svampar, som är effektivast på att bryta ner dött växtmaterial,stimuleras av god tillgång på syre och ganska hög temperatur. åtgärder som stimulerar mikrolivet är viktiga - dressning med sand är den mest effektiva åtgärden för dettamen regelbunden luftning är också viktig. Om vi inte lyckas skapa balans mellan bildande och nedbrytning av thatch måste den tas bort genom vertikalskärning eller motsvarande åtgärd. Särskild uppmärksamhet bör riktas mot spelytor med lite slitage liksom ytor som anlagts med färdigt gräs på rulle.

Sammendrag

Det er mange organismer som vil livnære seg i grasmatta på en golfbane. Noen av plantene som vokser der ikke ønsket, og kalles ugras. Noen mikroorganismer snylter på grasplantene våre og reduserer livskraft og spillekvalitet. De fleste av disse er sopper, og skaden de gjør omtales som plantesykdommer. Det er mange andre biologiske årsaker til redusert graskvalitet også. Skader fra insekter, nematoder, villsvin eller andre skadegjørere kan være betydelige, men omtales ikke her. Bekjempelsen av skadegjørerne forbindes ofte med kjemikaliesprøyting, men for å lykkes med å skape en fin golfbane må vi tenke forebyggende plantevern helt fra planlegging og anleggsfasen. Det gjelder å legge forholdene til rette for at graset skal trives og å gjøre det vanskelig for konkurrentene.   Et EU-direktiv slår fast at bekjempelse av ugras og sykdommer skal bygges på prinsippet om integrert plantevern. Det krever omfattende kunnskaper og forutsetter at alternativ til kjemikalier skal vurderes før det sprøytes. Bare personale med utdannelse og offentlig autorisasjon kan kjøpe og bruke kjemiske preparater på en golfbane, men alle kan bidra til å redusere bruken av kjemikalier. Det er også et spørsmål om holdninger blant golfere.   Denne teksten har ikke som mål å gi greenkeepere tilstrekkelig kunnskap til å gjennomføre integrert plantevern, men den skal gi golfere og styremedlemmer litt innsikt i temaet.  

Sammendrag

Freezing tolerance is a major component of winter hardiness of perennial grasses. Velvet bentgrass showed the same freezing tolerance as creeping bentgrass. Acclimation at temperatures above 0 ºC was associated with accumulation of nonstructural carbohydrates and enhanced plant survival after freezing. Acclimation at 2 ºC for 4 wk was more effective than for 2 wk and resulted in higher concentrations of fructans. Additional subzero acclimation at -2 ºC resulted in a reduction in fructans and higher concentration of reducing sugars; however, there was no additional improvement in freezing tolerance.  Protein analysis was performed using 2-D polyacrylamide gel electrophoresis. Nineteen protein spots were responsive to acclimation. Thirteen proteins were identified. Identified proteins belonged to metabolism, energy, disease/defence, and secondary metabolism functional groups.

Sammendrag

Cold acclimation plays a decisive role in turfgrass winter survival. This study was performed in collaboration with Rutgers University and University of Massachusetts (USA) to examine changes in carbohydrate levels in crown tissues during the first and second phases of cold acclimation in velvet bentgrass (Agrostis canina L.) and creeping bentgrass (A. stolonifera L.), and their association with freezing tolerance.. Four treatments representing different phases of cold acclimation were compared: (i) nonacclimated 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 ; (iii) as treatment (ii) but for 4 wk; and (iv) as treatment (iii) plus additional sub-zero acclimation in the dark at -2 °C for 2 wk. Velvet bentgrass and creeping bentgrass showed no difference in lethal temperatures for 50% of the test population (LT50) as estimated by whole plant survival. Acclimation at 2 °C for 2 and 4 weeks resulted in accumulation of sucrose and fructans, and significantly lowered LT50 as compared with nonacclimated plants.  Subzero acclimation resulted in less fructans, no difference in sucrose, and higher concentration of reducing sugars, but LT50 was not lower than after  acclimation at 2 °C for 4 weeks.  

Sammendrag

High fertilizers rates, especially of nitrogen (N) and phosphorus (P), are commonly used for turfgrass grow-in on sand-based soils. The United States Golf Association recommends preplant applications of up to 1.0 kg P and 0.5 kg N per 100 m2 followed by applications of up to 0.3 kg N/100 m2 every fifth day until plant cover is complete. Such high rates of N and P, given before roots have developed, incur a great risk for nutrient leaching. Irrigation several times per day to keep the seedbed constantly moist also contributes to this leaching potential. iSeed® is a seed coat patented by Yara International ASA and used for grass seed marketed by DLF Trifolium. The coat contains both fast-acting and slow-release fertilizers, in total 10% N and 2% P of coated seed weight. The objective of this research was to determine the effect of iSeed® on turf quality and nitrogen and phosphorus leaching during turfgrass grow-in on two sand-based rootzones. A two-factorial experiment was carried out in the field lysimeter facility at Bioforsk Øst Landvik, South East Norway (58o34"N, 8o52"E) from 22 June to 26 July 2010. The rootzone was maid up of either straight sand, SS, or Green Mix®, GM, (Høst AS, Grimstad Norway), the latter being SS amended with 20% (v/v) mature garden compost. The 2 m2 lysimeter plots were seeded with either iSeed® or uncoated seed of the same seed lot of perennial ryegrass (Lolium perenne L.) ‘Berlioz 1", the sowing rate in both cases corresponding to 20 g/m2 pure seed. Use of uncoated seed was combined with preplant applications of 4 g N (as calcium ammonium nitrate, 27% N) and 0.8 g P (as superphosphate, 8% P) per m2, i.e. the same amount of total nitrogen and phosphorus as in the iSeed® coating. One treatment included additional applications of 5 g N (as calcium nitrate, 15.5% N) and 1.0 g P (as superphosphate, 8% P) on day no. 10 and 21 after sowing. The experiment was irrigated heavily, especially during the first ten days after sowing. Observations were made over the 35 day period. The results revealed significant effects of rootzone composition (SS vs. GM) and/or seed type/additional fertilizer application on turfgrass ground cover, overall impression, colour, surface traction and root development. For all these characters, the GM rootzone showed significant benefits compared with the SS rootzone; however, total nitrogen leaching was 21 % higher and total phosphorus leaching 11 times higher from the GM than from the SS rootzone. Plots seeded with iSeed® usually performed slightly better than plots seeded with uncoated seed, but the visual effects were mostly insignificant and small compared to those of additional fertilizer applications on day no 10 and 21 after sowing. Use of iSeed® reduced nitrate and total nitrogen leaching by approximately 50% during the first 10 days after sowing, but caused no significant reduction during the following 25 days; these effects probably reflect the slow-release properties of 82% of the nitrogen contained in iSeed®. Leaching of phosphorus was not affected by either seed type or additional fertilizer application. Interactions between rootzone and seed type/additional fertilizer applications were mostly not significant.   We conclude that iSeed® has the potential to reduce nitrogen leaching during turfgrass establishment on sand-based rootzones.  However, as iSeed® does not eliminate the need for additional fertilizer inputs about two weeks after sowing, the environmental benefit seems to be of relatively short duration when growing in perennial ryegrass on athletic fields. The advantages of iSeed® may perhaps be more significant when growing in forage or amenity grasslands over a longer period and with less fertilizer inputs.   

Sammendrag

The results from two field trials (Landvik and Apelsvoll) showed that the use of a proper combination of nitrogen rate and topdressing level is very important for thatch control. In coastal areas with ample rainfall, velvet bentgrass should be dusted with find sand every week or at least every other week, totalling around 10-14 mm per season. Nitrogen rate should be held at a level just to get an acceptable color. Weekly grooming, monthly verticutting and spiking twice a year are also needed to control thatch on velvet bentgrass greens, but heavy mechanical treatments should be avoided due to slow recuperative capacity of velvet bentgrass.

Sammendrag

No significant differences in frost tolerance between velvet bentgrass and creeping bentgrass was observed when freezing occurred directly after acclimation. Acclimation under natural conditions was more effective than under controlled conditions. The quantitative and qualitative composition of nonstructural carbohydrates, particularly fructans, varied among bentgrass species, but did not correlate with frost tolerance. The accumulation of fructans may play a role in other aspects of winter hardiness. Subfreezing acclimation increased the frost tolerance of velvet bentgrass and creeping bentgrass.

Sammendrag

Vinteren i år gledet skifolket med mye snø og stabil kulde. Men var den lange og stabile vinteren bra for gresset?  I forskingsanlegget på Landvik har vi for en gangs skyld sett en del spennende vinterskader!

Sammendrag

Take-all patch (Gaeumannomyces graminis) and snow mould (Microdochium nivale and Typhula spp.) are common diseases on sand-based golf greens. Our objectives were (1) to study potential suppression of these diseases on new greens by inclusion of 20 % (v/v) garden compost ‘Green Mix" (GM) in the otherwise straight sand (SS) root zones; (2) to study efficacy against these diseases and leaching potential of fungicides approved for turfgrass use in Norway; and (3) to evaluate if repeated use of fungicide has any effect on microbial numbers in USGA root zones.  Prochloraz (0.45 kg a.i. ha-1),  azoxystobin + propiconazole, (0.200 + 0.125 kg a.i. ha-1), or trifloxystobin + propiconazole (0.1875 + 125 kg a.i. ha-1)  were applied for two consecutive years on two experimental greens, one including field lysimeters with either SS or GM root zones. Iprodione (2.250 kg a.i.ha-1) was applied only outside the lysimeter facility. None of the fungicides had any significant effect on take-all at the applied rates. Azoxystobin + propiconazole and trifloxystrobin + propiconazole were more efficient than prochloraz and iprodione in controlling snow mould. Leaching from SS root zones increased in the order trifloxystrobin< prochloraz