Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Soil aggregation and soil organic matter in conventionally and organically farmed Austrian Chernozems
Sandén, Taru ; Lair, Georg J. ; Leeuwen, Jeroen P. Van; Gísladóttir, Guorún ; Bloem, Jaap ; Ragnarsdóttir, Kristín Vala ; Steffens, Markus ; Blum, Winfried E.H. - \ 2017
Bodenkultur 68 (2017)1. - ISSN 0006-5471 - p. 41 - 55.
Aggregate hierarchy - Aggregate stability - Organic matter dynamics - Particulate organic matter (POM) - Solid-state 13C NMR spectroscopy
In order to study the soil aggregate distributions and soil organic matter (SOM), we sampled top- and subsoils in four intensively farmed croplands (two organic (Org-OB and Org-LA), and two conventional (Con-OB and Con-LA)) on Haplic Chernozems located in Marchfeld in the east of Vienna (Austria). Soil structure and SOM quantity, quality and distribution between free and occluded particulate organic matter and aggregate size fractions (<20 μm, 20-250 μm, 250-5000 μm) were studied by following a density fractionation procedure with low-energy ultrasound treatment. Te relation of the soil physicochemical (e.g., particle size distribution, pH, organic carbon, total nitrogen) and biological properties (e.g., fungal biomass, active fungi) with stable soil aggregate size fractions and SOM was studied. Te mean weight diameter (MWD) showed no significant difference between all studied sites and was between 3.8 mm and 10.0 mm in topsoils and between 6.7 mm and 11.9 mm in subsoils. In topsoils, the contents of calcium-acetate-lactate (CAL)-extractable P, active fungal biomass, dithionite-extractable Fe and sand were significantly positively correlated with the amount of the macroaggregates and with the MWD. We observed that most soil organic carbon, depending on soil texture, was stored in the microaggregate size classes <20 μm and 20-250 μm.
Serological Evidence for Schmallenberg Virus Infection in Sheep of Portugal 2014
Esteves, Fernando ; Mesquita, João R. ; Vala, Helena ; Abreu-Silva, Joana ; Poel, W.H.M. Van Der; Nascimento, Maria S.J. - \ 2016
Vector-Borne and Zoonotic Diseases 16 (2016)1. - ISSN 1530-3667 - p. 63 - 65.
Arbovirus - ELISA. - Schmallenberg virus - Seroprevalence - Sheep

Between November and December of 2014, a serosurvey was set up to evaluate the presence of Schmallenberg virus (SBV) antibodies in sheep of Portugal. Sera (n = 1068) were tested using an indirect enzyme linked immunosorbent assay (ID Screen® Schmallenberg virus indirect, IDvet Innovative Diagnostics Montpellier, France). The estimated occurrence of immunogobulin G (IgG) antibodies against SBV in sheep of Portugal was 12.8% (95% confidence interval 11.0-15.0%). This is the first study reporting the presence of SBV antibodies in sheep of Portugal.

Biologische bestrijding van de glimslak (Zonitoides arboreus) in potorchidee
Staaij, M. van der; Linden, A. van der; Grosman, A.H. - \ 2012
Wageningen UR Glastuinbouw (Rapport / Wageningen UR Glastuinbouw 1288) - 20
orchidaceae - potplanten - zonitoides arboreus - organismen ingezet bij biologische bestrijding - plaagbestrijding met predatoren - tests - efficiëntie - inventarisaties - gewasbescherming - huisjesslakken - pot plants - biological control agents - predator augmentation - efficiency - inventories - plant protection - snails
De glimslak Zonitoides arboreus veroorzaakt schade in de teelt van potorchidee in Nederland en is al ruim 10 jaar een bekende plaag van hetzelfde gewas in Hawaï. Literatuur en contacten (o.a. Naturalis) in binnen- en buitenland zijn geraadpleegd om kandidaat bestrijders te identificeren. Deze geven aan dat biologische bestrijding van de glimslak Zonitoides arboreus mogelijk is met bodemroofmijten, loopkevers, bodemroofwantsen, duizendpoten en glimwormen. Experts op het gebied van roofvliegen (Jean-Claude Vala en Lloyd Vernon Knutson) geven in hun standaard werk “Biology of snail-killing Sciomyzidae flies” aan dat in Noord Europa (Nederland) slakkendodende vliegen in de natuur voorkomen die glimslakken als prooi hebben. In het voorjaar, de zomer en het najaar van 2013 zijn geen natuurlijke vijanden aangetroffen in kweken van glimslakken die op twee verschillende plaatsen in Nederland in de natuur zijn gezet. Geen van de commercieel beschikbare bodemroofmijten (Macrocheles, Hypoaspis) en de larven en adulten van de roofkevers Atheata en Aleochara had een effect op het uitkomen van de eieren van de glimslak in predatietesten onder laboratoriumomstandigheden. Ook de aanwezige mijten, pseudoschorpioenen, spinnen en duizendpoten, in het materiaal verzameld bij telers, hadden geen effect op de ontwikkeling van de populatie glimslakken. The small snail Zonitiodes arboreus causes damage in orchids in The Netherlands and is for almost a decade a well-known pest in orchids in Hawaii. Literature and contacts in The Netherlands and abroad have been contacted to identify candidate natural enemies of Zonitoides arboreus. Biological control is possible with all sorts of soil dwelling predators (mites, beetles, bugs, centipedes and larvae of fire flies). Experts in the field of snail-killing flies, Jean-Claude Vala en Lloyd Vernon Knutson, present in their standard work “Biology of snail-killing Sciomyzidae flies” species which can be found in Northern Europe in nature. In spring, summer and autumn of 2013 pots with Zonitoides arboreus were placed in nature in two different regions of The Netherlands, but no natural enemies were found in that year. Commercially available soil dwelling predatory mites (Macrochelis and Hypoaspis) and larvae and adults of Atheata and Aleochara had no effect on eggs of Zonitoides arboreus. In the samples of the snails collected in orchids from different growers mites, spiders, pseudo scorpions and centipedes were found. None of them had an effect on the development of the snail population.
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