Consulta: creatorFacets:"Østergård, H."
Registros recuperados: 19
Data/hora: 12/06/2024 07:22:10

Simultaneous epidemic development of scald and net blotch on single leaf layers of a spring barley crop
Provedor de dados: 21
Autores: Vollmer, J.H.; Pinnschmidt, H.O.; Munk, L.; Østergård, H.
Background and objectives  Two pathogens growing on the same leaf compete for the same resources, i.e. space and plant nutrients. This may lead to density dependent disease development. The pathogens may also influence each other directly such that the influence of one on the other is more complex than a simple function of the area of the other pathogen. Different interaction types are, for example, competition, mutualism and exploitation. The importance of such interactions for epidemics of simultaneously occurring pathogens has received little attention. The objective of this study is to investigate the simultaneous epidemic development of Rhynchosporium secalis (causing scald) and Drechslera teres (causing net blotch) on spring barley under field...
Tipo: Conference paper, poster, etc.
Palavras-chave: Crop health; Quality; Protection Crop combinations and interactions Breeding; Genetics and propagation.
Ano: 2005
URL: http://orgprints.org/5974/1/5974.pdf

Stability of variety mixtures of spring barley
Provedor de dados: 21
Autores: Østergård, H.; Kristensen, K.; Jensen, J.W.
Six 3-component variety mixtures of spring barley and their component varieties have been grown in 17 different environments (3 years, 3 locations, 3 different growing systems). For three of the six mixtures, the grain yield was significantly higher than the average yield of its components; in none of the mixtures it was significantly lower. The variation in grain yield over environments of all variety mixtures was compared to the variation of all component varieties. The six mixtures were on average more stable than the 14 component varieties grown in pure stands with respect to actual yield as well as to rank values of yield.
Tipo: Conference paper, poster, etc.
Palavras-chave: Crop health; Quality; Protection Crop combinations and interactions Breeding; Genetics and propagation.
Ano: 2005
URL: http://orgprints.org/8152/1/8152.pdf

European perspectives of organic plant breeding and seed production in a genomics era.
Provedor de dados: 21
Autores: Lammerts van Bueren, E.T.; Wilbois, K-P.; Østergård, H.
For further optimisation of organic agricultural systems, more focus is required on  organically produced seeds and the development of better adapted varieties.  Organic plant breeding and seed production need to comply with the concept of  naturalness as applied in organic agriculture, which not only includes the nonchemical  and agro-ecological approaches, but also the integrity of life approach.  As organic environments are less controllable and are more variable, breeding  should aim at improved yield stability and product quality by being adapted to  organic soil fertility as well as sustainable weed, pest and disease management.  Also the ability to produce economicacceptable seed yield avoiding seed-borne  diseases should be included. On the short...
Tipo: Journal paper
Palavras-chave: "Organics" in general Breeding; Genetics and propagation.
Ano: 2007
URL: http://orgprints.org/10734/1/Lammerts_van_Bueren_et_al_2007_JARTS_SP_89.pdf

Predicting spring barley yield from variety-specific yield potential, disease resistance and straw length, and from environment-specific disease loads and weed pressure
Provedor de dados: 21
Autores: Østergård, H.; Kristensen, K.; Pinnschmidt, H.O.; Hansen, P.K.; Hovmøller, M.S.
Abstract For low-input crop production, well-characterised varieties increase the possibilities of managing diseases and weeds. This analysis aims at developing a framework for analyzing grain yield using external varietal information about disease resistance, weed competitiveness and yield potential and quantifying the impact of susceptibility grouping and straw length scores (as a measure for weed competitiveness) for predicting spring barley grain yield under variable biotic stress levels. The study   comprised 52 spring barley varieties and 17 environments, i.e., combinations of location, growing system and year. Individual varieties and their interactions with environments were analysed by factorial regression of grain yield on external variety...
Tipo: Journal paper
Palavras-chave: Crop health; Quality; Protection Weed management Breeding; Genetics and propagation.
Ano: 2008
URL: http://orgprints.org/14957/1/14957.pdf

Energy efficiency of biomass production in managed versus natural temperate forest and grassland ecosystems
Provedor de dados: 21
Autores: Callesen, I.; Østergård, H.
In a conceptual model study based on literature data from Danish ecosystems, energy yield from biomass production was compared in two semi-natural ecosystems (broadleaved forest and grassland) and their managed counterparts. The highest net energy yield of harvested biomass was obtained in the managed grassland system. The energy efficiency in terms of output:input ratios were about 190:1 in the managed beech forest and 6:1 in the managed grassland. This is discussed in relation to nitrogen cycling, carbon storage and energy efficiency of biomass production.
Tipo: Conference paper, poster, etc.
Palavras-chave: Pasture and forage crops; Biodiversity and ecosystem services.
Ano: 2008
URL: http://orgprints.org/12222/1/Callesen_12222_ed.doc

Time for a shift in crop production: embracing complexity through diversity at all levels
Provedor de dados: 21
Autores: Østergård, H.; Finckh, M.R.; Fontaine, L.; Goldringer, I.; Hoad, S.P.; Kristensen, K.; Lammerts van Bueren, E.T.; Mascher, F.; Munk, L.; Wolfe, M.S.
A radical shift in our approach to crop production is needed to ensure food security and to address the problems of soil degradation, loss of biodiversity, polluted and restricted water supplies, coupled with a future of fossil fuel limitations and increasingly variable climatic conditions. An interdisciplinary network of European scientists put forward visions for future crop production embracing the complexity of our socio-ecological system by applying the principle of diversity at all levels from soil micro-organisms to plant varieties and cropping systems. This approach, integrated with careful deployment of our finite global resources and implementation of appropriate sustainable technology, appears to be the only way to ensure the scale of system...
Tipo: Journal paper
Palavras-chave: Production systems Soil quality Systems research and participatory research Recycling; Balancing and resource management Breeding; Genetics and propagation Regulation.
Ano: 2009
URL: http://orgprints.org/21749/1/21749.pdf

Increased yield and yield stability in variety mixtures of spring barley
Provedor de dados: 21
Autores: Østergård, H.; Jensen, J.W.
In the DARCOF II BAR-OF project, six variety mixtures are studied in organic as well as conventional growing systems in the period 2002 to 2005. The focus has been on competitive ability of the component varieties in addition to their disease resistance. This study is included in a European Network on sustainable low-input cereal production focusing on varietal characteristics and crop diversity (SUSVAR - COST 860), initiated in 2004. The following is based on papers presented at two SUSVAR workshops.
Tipo: Journal paper
Palavras-chave: Crop health; Quality; Protection Crop combinations and interactions Breeding; Genetics and propagation.
Ano: 2005
URL: http://orgprints.org/8158/1/8158.pdf

Disease severity and grain yield of spring barley variety mixtures grown under organic and conventional conditions
Provedor de dados: 21
Autores: Østergård, H.; Kristensen, K.; Hovmøller, M.S.; Jensen, J.W.
Despite quite intensive testing of varieties, predictions of future performance of varieties, when grown on specific locations, are known to be nearly impossible; this especially within organic growing systems, where no pesticides and fertilizers can help stabilize yield. Therefore, using mixtures of appropriate varieties might be a way to obtain more stable and acceptable yields. Variety mixtures have so far been studied mostly under conventional farming conditions and focus has often been to characterize disease progress of one pathogen. Here we consider simultaneously four important foliar diseases on spring barley grown in organic as well as conventional growing systems. Further, we study the changes in disease severity of variety mixtures when...
Tipo: Conference paper, poster, etc.
Palavras-chave: Crop health; Quality; Protection Crop combinations and interactions Breeding; Genetics and propagation Biodiversity and ecosystem services.
Ano: 2004
URL: http://orgprints.org/8145/1/8145.pdf

Sustainability assessment of wheat production using Emergy
Provedor de dados: 21
Autores: Coppola, F.; Haugaard-Nielsen, H.; Bastianoni, S.; Østergård, H.
Sustainability of crop production has to be given high priority when global biomass resources are limited. Here emergy evaluation is applied in order to assess sustainability of crop production exemplified by winter wheat. Emergy evaluation takes into account all inputs involved in a production system (i.e. renewable and non-renewable, local and imported) and transforms them into a common measure of direct and indirect solar energy requirement. The evaluation of winter wheat production is conducted by comparing conventional and organic management on two soil types using Danish reference conditions. The resource use efficiency of wheat production per kg biomass is higher using conventional management practices. This is due to high yield based on large use...
Tipo: Conference paper, poster, etc.
Palavras-chave: Environmental aspects Cereals; Pulses and oilseeds Farm nutrient management.
Ano: 2008
URL: http://orgprints.org/11381/2/11381.pdf

Composition of variety mixtures in barley and wheat
Provedor de dados: 21
Autores: Østergård, H.
Breeding within the last 50 years has focused on developing genetic uniform crops/varieties for farmers to be able to produce homogeneous products to be sold. Therefore, especially for selfing crops like wheat and barley where nearly all plants in a field are genetical identical, specific tools have to be applied to ensure genetic diversity. Among these tools is the use of variety mixtures. Principles for composing variety mixtures are to a large extent based on disease resistance characteristics and this is insufficient to predict the performance of the mixtures. Biological principles for interactions between varieties will be of relevance not only to organic farming but also to conventional agriculture where variety mixtures have been used for many years...
Tipo: Conference paper, poster, etc.
Palavras-chave: Crop health; Quality; Protection Crop combinations and interactions Breeding; Genetics and propagation.
Ano: 2005
URL: http://orgprints.org/8253/1/8253.pdf

Assessment of disease in low-input cereal cropping systems and variety trials
Provedor de dados: 21
Autores: Hovmøller, M.S.; Pinnschmidt, H.; Willas, J.; Østergård, H.
Disease assessment is the basis for describing disease resistance characteristics of commercial varieties in national variety lists for all crops where disease is considered a problem. It is well known that ‘disease’ in a specific situation depends on a whole range of interacting hosts, pathogens and environmental conditions. However, the biological complexity conflicts with the wish to express disease resistance characteristics of a variety as a single score per disease. This problem will be illustrated by basic dynamics of growth and senescence of both host and pathogen over time. Disease expressed in terms of absolute diseased leaf area, disease relative to total leaf area or green leaf area will be discussed in general. Two particular problems in...
Tipo: Conference paper, poster, etc.
Palavras-chave: Crop health; Quality; Protection Breeding; Genetics and propagation.
Ano: 2005
URL: http://orgprints.org/8229/1/8229.pdf

Approaches for field assessment of resistance to leaf pathogens in spring barley  varieties
Provedor de dados: 21
Autores: Pinnschmidt, H.O.; Hovmøller, M.S.; Østergård, H.
The resistance of spring barley varieties to powdery mildew, leaf rust, leaf scald and net blotch was characterized by using results from inoculated small-plot nurseries and larger survey plots subject to natural infection. The experiments were conducted in different environments. Both trial types often yielded complementary results with respect to the ranking of varieties suggesting that a recommended variety characterization should include both naturally infected survey-type trials and nursery trials in which the most relevant pathogen isolates and/or isolate mixtures or populations are used for inoculation. Average and median values of the diseased leaf area of a variety were highly correlated with each other and with the genotype main effect determined...
Tipo: Journal paper
Palavras-chave: Crop health; Quality; Protection Breeding; Genetics and propagation.
Ano: 2006
URL: http://orgprints.org/8203/1/8203.pdf

The role of molecular markers and marker assisted selection in breeding for organic agriculture
Provedor de dados: 21
Autores: Lammerts van Bueren, E.T.; Backes, Gunter; de Vriend, H.C.; Østergård, H.
Plant geneticists consider molecular marker assisted selection a useful additional tool in plant breeding programs to make selection more efficient. Standards for organic agriculture do not exclude the use of molecular markers as such, however for the organic sector the appropriateness of molecular markers is not self-evident and is often debated. Organic and low-input farming conditions require breeding for robust and flexible varieties, which may be hampered by too much focus on the molecular level. Pros and contras for application of molecular markers in breeding for organic agriculture was the topic of a recent European plant breeding workshop. The participants evaluated strengths, weaknesses, opportunities, and threats of the use of molecular markers...
Tipo: Journal paper
Palavras-chave: Breeding and genetics.
Ano: 2010
URL: http://orgprints.org/18232/4/18232.pdf

Sortsblandingers udbyttestabilitet og udbyttepotentiale
Provedor de dados: 21
Autores: Østergård, H.; Jensen, J. Willas.
Højere udbytte og bedre udbyttestabilitet er ofte fundet i sortsblandinger i vårbyg sammenlignet med målestandarder og komponentsorter, bl.a. i FØJO II projektet BAROF.
Tipo: Conference paper, poster, etc.
Palavras-chave: Crop health; Quality; Protection Crop combinations and interactions Breeding; Genetics and propagation.
Ano: 2006
URL: http://orgprints.org/8157/1/8157.pdf

Characteristics of spring barley varieties and crop diversity for  organic farming and variety testing
Provedor de dados: 21
Autores: Østergård, H.; Jensen, J.W.
Results from Danish spring barley variety trials including about 50-120 varieties and variety mixtures on three locations over three years under organic as well as conventional farming systems demonstrate the importance of genotype-environment interactions. This has implications for potential future organic VCU-testing; here results are shown for grain yield. Further, grain yield results from of six variety mixtures and their 14 component varieties indicate that variety mixtures may be less influenced by genotype-environment interactions compared to pure line varieties.
Tipo: Conference paper, poster, etc.
Palavras-chave: Regulation Crop combinations and interactions Breeding; Genetics and propagation.
Ano: 2005
URL: http://orgprints.org/8155/1/8155.pdf

Vekselvirkning mellem plantesygdomme påvirker sygdomsudviklingen
Provedor de dados: 21
Autores: Vollmer, J.H.; Østergård, H.; Pinnschmidt, H.; Munk, L.
Sygdomme i planter kan være forårsaget af mange forskellige mikroorganismer, og ofte vil der i en enkelt afgrøde og på én plante være flere arter tilstede samtidigt. På trods af denne erfaring har der været tradition for at forske i sygdomme enkeltvis, og betydningen på det totale sygdomsniveau af vekselvirkninger mellem de enkelte patogener er kun blevet studeret i begrænset omfang. Her beskrives vekselvirkningen mellem sygdommene bladplet og skoldplet på byg i markforsøg.
Tipo: Journal paper
Palavras-chave: Crop health; Quality; Protection.
Ano: 2005
URL: http://orgprints.org/8168/1/8168.pdf

Changes in variety composition in spring barley mixtures over years
Provedor de dados: 21
Autores: Østergård, H.; Backes, G.
In a variety mixture, competition between component varieties as well as differences in performance of the components may lead to changes in the proportion of component varieties between seed sown and seed harvested. This will imply that farm saved seeds of variety mixtures will constitute an evolving population. How much changes are found over a short period of years and in different environments?  In 2002, six 3-component variety mixtures of spring barley were constructed based on altogether 14 mostly high-yielding varieties. The six mixtures and derivatives of these were included in the large Danish BAR-OF variety trials in the years 2002-2005 (Østergård et al. 2005). Here, a subset of this material is considered: only trials from 2003 and 2004 at the...
Tipo: Conference paper, poster, etc.
Palavras-chave: Crop combinations and interactions.
Ano: 2006
URL: http://orgprints.org/10343/1/10343.doc

Værdien af sygdomsresistens i økologisk dyrket vårbyg
Provedor de dados: 21
Autores: Hovmøller, M.S.; Thomsen, I.; Kristensen, K.; Østergård, H.
Bladsygdomme kan være et væsentligt problem både i konventionel og økologisk dyrkning af vårbyg. Der er gode muligheder for at forebygge bladsygdomme ved korrekt sortsvalg, såfremt man lægger vægt på sortens (eller sortsblandingens) resistensegenskaber. Det er således afgørende at kende sortens resistens mod specielt de sygdomme, som har størst sandsynlighed for, baseret på den enkeltes erfaringer, at kunne blive et problem. Udover sortsegenskaber vil sygdomsniveauet for den enkelte sygdom i den enkelte mark afhænge af det lokale smittetryk i begyndelsen af vækstsæsonen, jordens næringsstofbalance- og frigivelse, mikrobiel aktivitet samt vind og vejr.
Tipo: Conference paper, poster, etc.
Palavras-chave: Crop health; Quality; Protection.
Ano: 2006
URL: http://orgprints.org/7910/1/7910.pdf

Association mapping for barley traits related to organic farming
Provedor de dados: 21
Autores: Backes, G.; Kristensen, K.; Østergård, H.
In context of a larger project dealing with the traits of barley that are related to organic farming (BAR-OF), we performed an association mapping in order to dertermine the genetic loci linked with the respective traits. In two subsequent years (2002 and 2003), we used field results from 96 barley lines and varieties, partially overlapping between the years. The lines/varieties were grown on three Dansih locations (Flakkebjerg, Foulum and Jyndevad). For Foulum and Flakkebjerg, we observed both fields grown under organic and conventional regime; for Jyndevad only fields cultivated under organic conditions were ecploited. Neither in the organic nor in the conventional fields; diseases were controlled chemically. In the resulting five environments per year,...
Tipo: Conference paper, poster, etc.
Palavras-chave: Cereals; Pulses and oilseeds Breeding; Genetics and propagation.
Ano: 2007
URL: http://orgprints.org/21774/7/21774.pdf