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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    Microbially healthy water in greenhouse horticulture : Prevention and removal of biofilm formation in zero discharge cultivation systems
    Ruijven, J.P.M. van; Persijn, A. ; Learbuch, K.L.G. ; Verschoor, A.M. ; Bel, N. van - \ 2020
    Bleiswijk : Stichting Wageningen Research, Wageningen Plant Research, Business Unit Greenhouse Horticulture (Report / Stichting Wageningen Research, Wageningen Plant Research, Business unit Greenhouse Horticulture WPR-905) - 86
    Management of biofilms in irrigation lines is an important aspect to achieve Zero Liquid Discharge cultivation systems, as is the goal for Dutch greenhouse horticulture by 2027. A test system (in triplicate) and a protocol were developed and build to test the effectiveness of technologies and products for removal and prevention of formation of biofilms. Under greenhouse circumstances (temperature, water composition, irrigation line material, system length, etc.) this system and protocol have shown to be capable to produce a reproducible biofilm in three parallel test systems. Five technologies have been tested with this system: • (1) Oxyl-PRO S silver stabilised H2O2 has shown to be effective to prevent biofilm formation, but did not show a significant effect in biofilm removal. • (2) SureFlow ClO2 has shown to be effective in both removal of an existing biofilm and prevention of biofilm formation. • (3) Antibacterial pipelines, (4) AQUA4D® and (5) SonoPure Ultrasound did not show a significant effect in both prevention of biofilm formation and removal of an existing biofilm. None of the tested technologies had a selective effect on the composition of the microbial community in the biofilm.
    The pebble in the shoe : Gods on the run, the public, and the politics of life on the Nayarit coast, Mexico
    Regalado, Francisca López ; Verschoor, Gerard - \ 2020
    Journal of Rural Studies 78 (2020). - ISSN 0743-0167 - p. 292 - 303.
    Nayarit - Nayéeri - Ontologies - Politics of life - The public - Wixaritari

    This article aims to describe and analyse the emergence and constitution of the public in the coastal town of San Blas, Nayarit, Mexico. Based on Rancière's notion of politics, Dewey's concept of the public, and relational approaches to ontology, we draw on ethnographic, archival and interview research to follow the tracks of human and non-human actors laying competing claims on a site considered to have different characteristics within different ontologies. We show how the worlds of progress that potentially link the site to real estate profits, tourism and fisheries development enter into conflict with those of Wixaritari and Nayéeri Indigenous peoples defending an alliance between nature and spirituality. Enacted in and through the same as their opponents' materiality, Indigenous renderings of the conflict work as a pebble in the shoe for traditional politics. In particular, we focus on the way in which the site -and its entities-becomes public and political as it gradually surrounds itself with an ontologically heterogeneous audience, and how this is dealt with in practice. We argue that, as an effect, the notion of ‘the political’ changes to encompass not only a politics of who, but also a politics of what –of life itself. We conclude that the public emerges from, and is constituted by, ontological difference.

    Insects for peace
    Barragán-Fonseca, Katherine Y. ; Barragán-Fonseca, Karol B. ; Verschoor, Gerard ; Loon, Joop J.A. van; Dicke, Marcel - \ 2020
    Current Opinion in Insect Science 40 (2020). - ISSN 2214-5745 - p. 85 - 93.

    Insects such as the black soldier fly (BSF) are a nutritious feed component for livestock with high protein levels. BSF can be reared on a wide range of organic residual streams. This allows for local production within a circular agriculture, decoupling livestock production from import of expensive feed components, such as fishmeal or soymeal. Rearing of BSF can be done by smallholder farmers, thus contributing to their livelihood, economic sustainability and social status. Smallholder farmers contribute importantly to food security, which is a prerequisite for a stable society. In armed conflicts, smallholder farmers are usually the first to suffer. In countries recovering from conflict, agricultural development should focus on restoring food production by smallholder farmers, improving their socio-economic position, thereby contributing to sustainable development goals 2 (zero hunger) and 16 (peace and justice). Here, we focus on these SDGs with an example of reintegration of ex-combatants as smallholder insect producers in post-conflict Colombia.

    Effects of Dutch livestock production on human health and the environment
    Post, Pim M. ; Hogerwerf, Lenny ; Bokkers, Eddie A.M. ; Baumann, Bert ; Fischer, Paul ; Rutledge-Jonker, Susanna ; Hilderink, Henk ; Hollander, Anne ; Hoogsteen, Martine J.J. ; Liebman, Alex ; Mangen, Marie-Josée J. ; Manuel, Henk Jan ; Mughini-Gras, Lapo ; Poll, Ric van; Posthuma, Leo ; Pul, Addo van; Rutgers, Michiel ; Schmitt, Heike ; Steenbergen, Jim van; Sterk, Hendrika A.M. ; Verschoor, Anja ; Vries, Wilco de; Wallace, Robert G. ; Wichink Kruit, Roy ; Lebret, Erik ; Boer, Imke J.M. de - \ 2020
    Science of the Total Environment 737 (2020). - ISSN 0048-9697
    Animal production - Climate impact - Disability-adjusted life year (DALY) - Environmental impact - Livestock farming

    Observed multiple adverse effects of livestock production have led to increasing calls for more sustainable livestock production. Quantitative analysis of adverse effects, which can guide public debate and policy development in this area, is limited and generally scattered across environmental, human health, and other science domains. The aim of this study was to bring together and, where possible, quantify and aggregate the effects of national-scale livestock production on 17 impact categories, ranging from impacts of particulate matter, emerging infectious diseases and odor annoyance to airborne nitrogen deposition on terrestrial nature areas and greenhouse gas emissions. Effects were estimated and scaled to total Dutch livestock production, with system boundaries including feed production, manure management and transport, but excluding slaughtering, retail and consumption. Effects were expressed using eight indicators that directly express Impact in the sense of the Drivers-Pressures-State-Impact-Response framework, while the remaining 14 express Pressures or States. Results show that livestock production may contribute both positively and negatively to human health with a human disease burden (expressed in disability-adjusted life years) of up to 4% for three different health effects: those related to particulate matter, zoonoses, and occupational accidents. The contribution to environmental impact ranges from 2% for consumptive water use in the Netherlands to 95% for phosphorus transfer to soils, and extends beyond Dutch borders. While some aggregation across impact categories was possible, notably for burden of disease estimates, further aggregation of disparate indicators would require normative value judgement. Despite difficulty of aggregation, the assessment shows that impacts receive a different contribution of different animal sectors. While some of our results are country-specific, the overall approach is generic and can be adapted and tuned according to specific contexts and information needs in other regions, to allow informed decision making across a broad range of impact categories.

    CATT bestrijdt aardbeimijt zonder chemie
    Verschoor, Jan - \ 2019

    De chemievrije naoogstbehandeling CATT is een succes in de behandeling van aardbeimoederplanten tegen aardbeimijt. Het is een milieuvriendelijk alternatief voor methylbromide. Onderzoeker Jan Verschoor denkt dat er veel meer mogelijkheden zijn voor uitgangsmateriaal en plantaardige producten. 'Niet langer wachten met nieuwe toepassingen.'

    Doorstralen van verse tuinbouwproducten
    Helsen, H.H.M. ; Hogeveen-van Echtelt, Esther ; Rozen, K. van; Verschoor, J.A. ; Vijn, M.P. - \ 2019
    Wageningen : Wageningen University & Research - 4 p.
    Phytotec - fytosanitair - doorstralen - tuinbouwproducten
    Door toenemende wereldhandel nemen fytosanitaire risico’s toe. Ongewenste import van vreemde plaag organismen kan leiden tot grote directe en indirecte schade, en kan onomkeerbare gevolgen hebben.
    Agroecological peasant territories: resistance and existence in the struggle for emancipation in Brazil
    Berg, Leonardo van den; Goris, M.B. ; Behagel, J.H. ; Verschoor, G. ; Turnhout, E. ; Botelho, M.I.V. ; Silva Lopes, I. - \ 2019
    The Journal of Peasant Studies (2019). - ISSN 0306-6150
    Agri-food system transformation - food movements - peasant movements - upscaling agroecology

    We explore peasant territories as an emancipatory alternative in the context of authoritarian populism and neo-liberalism by focusing on two agroecological peasant territories in Brazil. We argue that territories harbour socio-ecological, cultural-political and politico-institutional bases that engender different forms of resistance and existence. Peasant territories build and defend emancipatory alternatives by creating self-governed knowledge and production systems, by problematising and mobilising against exploitative relations, and by transforming parts of the state. We conclude that peasant territories provide a basis for emancipatory transformation. What is more, they can be considered as emancipatory alternatives in themselves.

    Tussenevaluatie van de nota ‘Gezonde Groei, Duurzame Oogst’ : deelproject Milieu
    Verschoor, A. ; Zwartkruis, J. ; Hoogsteen, M. ; Scheepmaker, J. ; Jong, F. de; Knaap, Y. van der; Leendertse, P. ; Boeke, S. ; Vijftigschild, R. ; Kruijne, R. ; Tamis, W. - \ 2019
    Den Haag : Planbureau voor de Leefomgeving (RIVM rapport 2019-0044) - 167
    Resignification practices of youth in zona da mata, Brazil in the transition toward agroecology
    Goris, Margriet ; Berg, Leonardo van den; Silva Lopes, Ivonete da; Behagel, Jelle ; Verschoor, Gerard ; Turnhout, Esther - \ 2019
    Sustainability 11 (2019)1. - ISSN 2071-1050
    Agroecology - Framing strategies - Gender - Repeasantization - Resignification - Social movement - Transition - Youth

    Youth play an important role in the transition toward agroecology through practices of resignification. This article discusses how young people resignify agroecology by taking part in education initiatives that originate from social movements, and that aim to strengthen young peoples' abilities to reflect on their practices and realities. We used action research to create films with young agroecologists in the region of Zona da Mata Mineira, Brazil. Our analysis draws on films, interviews and participatory observations made during thirteen workshops to visualize the agroecological practices and visions of youth. We explore how social frames-e.g., the specific ways in which people understand reality-shape practices and how these frames are actively changed by youth. The findings show how frames are changed during (1) frame amplification by building on existing local values; (2) frame bridging by linking with other social movements; (3) frame extension by inclusion of new frames; and (4) frame transformation by altering the meaning of agroecology. We find that young people who engage with agroecology contribute to processes of repeasantization that rework local culture to be more inclusive of different populations, generations and genders, and that they foster an appreciation of the interconnectedness of humans and nature.

    Aandachtspunten oogst en bewaring Conference en Elstar
    Hogeveen-van Echtelt, Esther ; Geijn, F.G. van de; Verschoor, J.A. ; Wild, Hans de; Wenneker, M. ; Peeters, Jan - \ 2018
    Wageningen University & Research - 15 p.
    Ingestion and chronic effects of car tyre tread particles on freshwater benthic macroinvertebrates
    Redondo Hasselerharm, P.E. ; Ruijter, V. de; Mintenig, Svenja ; Verschoor, A. ; Koelmans, A.A. - \ 2018
    Environmental Science and Technology 52 (2018)23. - ISSN 0013-936X - p. 13986 - 13994.
    Micronized particles released from car tires have been found to contribute substantially to microplastic pollution, triggering the need to evaluate their effects on biota. In the present study, four freshwater benthic macroinvertebrates were exposed for 28 days to tread particles (TP; 10-586 µm) made from used car tires at concentrations of 0, 0.1, 0.3, 1, 3 and 10% sediment dry weight. No adverse effects were found on the survival, growth and feeding rate of Gammarus pulex and Asellus aquaticus, the survival and growth of Tubifex spp., and the number of worms and growth of Lumbriculus variegatus. A method to quantify TP numbers inside biota was developed and here applied to G. pulex. In bodies and faces of G. pulex exposed to 10% car tire TP, averages of 2.5 and 4 tread particles per organism were found, respectively. Chemical analysis showed that, although car tire TP had a high intrinsic zinc content, only small fractions of the heavy metals present were bioavailable. PAHs in the TP-sediment mixtures also remained below existing toxicity thresholds. This combination of results suggests that real in situ effects of TP and TP-associated contaminants when dispersed in sediments are probably lower than those reported after forced leaching of contaminants from car tire particles.
    Editorial: Algal technologies for wastewater treatment and resource recovery :
    Muñoz, Raul ; Temmink, Hardy ; Verschoor, Anthony M. ; Steen, Peter Van Der - \ 2018
    Water Science and Technology 78 (2018)1. - ISSN 0273-1223 - 2 p.
    Fytosanitaire na-oogst behandel- en detectietechnieken voor plaagorganismen in tuinbouw
    Qiu, Y. ; Hogeveen-van Echtelt, Esther ; Verschoor, J.A. ; Rozen, K. van; Ruizendaal, J.L. ; Helsen, H.H.M. ; Booij, C.J.H. ; Dam, M.F.N. van; Sluis, A.A. van der; Pekkeriet, E.J. ; Vreeburg, P.J.M. ; Vijn, M.P. ; Spoorenberg, P.M. - \ 2018
    Wageningen University & Research (Rapport WPR 751) - 81 p.
    2018 Huamentong Fruit Losses
    Verschoor, Jan - \ 2018
    Microalgae as renewable raw material for bioproducts : identification and biochemical composition of microalgae from a raceway pond in The Netherlands
    Broek, L.A.M. van den; Wagemakers, M.J.M. ; Verschoor, A.M. ; Frissen, A.E. ; Haveren, J. van; Blaauw, R. ; Mooibroek, H. - \ 2018
    In: Biomass as Renewable Raw Material for Bioproducts of High Tech-Value / Popa, Valentin, Volf, Irina, Elsevier - ISBN 9780444637741 - p. 39 - 68.
    Microalgae contain valuable lipids, proteins, and carbohydrates that can be used for food and nonfood applications. Here we describe the general aspects of the production, identification, and biorefinery of microalgae. In addition, as an illustrative example we present data obtained over the course of one year from two neighboring seminatural open raceway ponds located in Borculo in the eastern part of the Netherlands. A stable community developed in these ponds and the green microalgae species dynamics and lipid, protein, and carbohydrate profiles of the biomass were investigated. Throughout the year, Desmodesmus species were the most abundant green microalgae present. The biomass harvested from the raceway ponds showed a rather similar lipid, protein, and carbohydrate content over the year. Glucose and mannose were the dominant neutral sugars, and linolenic acid (C18:3) was the major fatty acid in the oil fraction.
    Going for the dough : Engaging governmental funds in the Ciénega de Zacapu, Mexico
    Servin Juárez, Fidencio - \ 2018
    Wageningen University. Promotor(en): L.E. Visser, co-promotor(en): G.M. Verschoor. - Wageningen : Wageningen University - ISBN 9789463438292 - 167

    This study follows a planned development intervention involving greenhouse production systems for tomatoes. The intervention played out in Mexico, where the Planning Sub- Committee for Regional Development (SUPLADER) promoted a strategy for the "development" of the Zacapu region in Michoacán, from 2002 to 2005. The intervention is illustrated through a detailed, in-depth ethnographic case study of the way in which the Unión de Invernaderos Ruta de la Libertad (a USPR or Union of Rural Producers Association) sought to materialize a greenhouse project.

    Using an actor-oriented perspective (Long, 2001; Nuijten, 2001; Diego, 1997) and the concepts of actor’s agency, networks, associations, collectives and organizing processes, the study aims to understand the character of intervention, and shows how programs and development projects serve different purposes – purposes which symbiotically relate to the prevailing social conditions. As a general conclusion, I argue that what is called “the dough” (la lana) is what drives the dynamics of development intervention. While important, it is central to understand the different roles “the dough” plays in these intervention settings: for planners, it is the means to accomplish development, whereas for project beneficiaries it is a goal in itself.

    Chapter 1 elaborates on the general context of planned intervention in Michoacán’s Zacapu region, delineates the theoretical framework, presents the main research question (How do stakeholders organize themselves around the greenhouse project, and how do they redefine the view of planned development by the local government?) and elaborates on the methodology employed.

    Chapter 2 describes the organizing processes underlying implementation of the greenhouse project in the Zacapu - Ciénega region. It explains how, in order to acquire resources for the project, stakeholders organized into groups, forming Rural Production Associations (SPRs) and Unions of Rural Producers’ Associations (USPRs). As a result, a total of 28 SPRs were formed. For the most part, members of these SPRs had extensive, prior experience in organizing and participating in programs similar to those promoted by SUPLADER.

    Chapter 3 describes the practices of the eight groups (SPR) who got no resources from SUPLADER and seek to compensate for an initial investment from the Alliance for the Countryside (Alianza). To complete the project file, the groups were linked to government agencies, municipalities and communities as well as with external agents (firms) to use the register as a professional services provider (PSP) and enter the file to the Alianza program. In addition, power differences and conflict relationships were evident (Lukes, 1974); conditions that led to negotiation (Diego, 1997).

    Advisor firms were considered necessary for the negotiations since their capabilities were required and considered essential for the expected benefit of the Asociación, although they appeared to be a very powerful party. Despite the regulations established by the State to exercise governmental programs, the parties responsible for exercising them applied ambiguous criteria.

    Chapter 4 describes the development of an ideal configuration of greenhouses that included technological, social and cultural elements associated with safety practices, automation and demanding consumers located in an international market. This perception was far from the project conditions of greenhouses in La Ciénega; however, it did not prevent generating expectations among the SPRs. For these actors, the greenhouse became an alternative livelihood, income, and development opportunity.

    To interpret the processes described I used Latour’s (2008) notion of a sociology of associations; this allowed me to interpret how actor-networks were incorporated in the greenhouse project.

    Chapter 5 describes a breakaway attempt from the Asociación spearheaded by 17 SPRs that chose to build their greenhouses with an alternative hardware supplier (ACEA). To obtain the necessary funds new negotiations were started with a range of agencies. The move eventually strengthened the Asociación and its institutional embeddedness.

    In Chapter 6, the Asociación is shown to be a heterogeneous collective with different agendas. This resulted in several conflicts, some of them, involving the advisory offices that intended to take the resources (“the dough”) from the project. Nonetheless, a regional bank authorized a cash disbursement for the initial stage of the greenhouse project.

    Chapter 7 presents the final stage of SUPLADER Zacapu’s greenhouse project. After complex negotiations and conflicts within the Asociación, complementary credit was obtained for the construction of the greenhouse. However, during a municipal election campaign key figures in charge of implementation changed position; this led to a change in project conditions, and the Asociación had to face interventions from external actors. The negotiation game restarted and triggered a new set of strategies (amongst others to obtain money directly through the new SEPLADE delegate). Eventually, some of the Asociación’s funds were reappropriated and assigned to USPR Agrícola Tsakapu and different factions (vying for of resources) resulted fom this.

    Chapter 8 provides the discussion and conclusion to this thesis, with insights that build on Mosse’s (2005) argument that policies to promote development are associated to organizational demands and needs to maintain existing relationships (rather than promoting a previously defined policy). However, in the case of La Ciénega, the agents of change (including the Michoacán Congress) supported and pushed through planners’ development initiatives. In line with Ferguson (1994), I conclude that development must be understood in relation to the political-economic-cultural interests of those behind its design and implementation. Rather than linear, hegemonic and rigid, however, actors’ practices and strategies mould and twist planned development intervention to suit their needs and desires.

    Radical ruralities in practice: Negotiating buen vivir in a Colombian network of sustainability
    Chaves, M.C. ; Macintyre, Thomas ; Verschoor, G.M. ; Wals, A.E.J. - \ 2018
    Journal of Rural Studies 59 (2018). - ISSN 0743-0167 - p. 153 - 162.
    This paper explores the emerging concept of buen vivir – interpreted as integrative and collective well-being – as it is being envisioned and practiced by a network of sustainability initiatives in Colombia. As an example of a transition narrative currently taking place in Latin America and beyond, buen vivir represents a turn towards a more biocentric, relational and collective means of understanding and being in the world. Yet despite the many discourses into buen vivir (many of which tout it as an alternative to neoliberal models of development), there is a general lack of research into its varied forms of application, especially in terms of lived experiences. Drawing on the new ruralities literature, this paper explores the extent to which buen vivir visions and practices represent radical new ruralities – so-called alternatives to development. Data were collected from individuals and ecological communities in predominantly rural areas who are members of the Council of Sustainable Settlements of the Americas (CASA), a network which promotes many of the principles of buen vivir. Through participatory methods, results demonstrate that CASA visions are based on constructing territorial relations through intercultural knowledge exchange and experimentation into alternative lifestyles. Despite the substantial challenges and contradictions of putting these visions into practice, we argue that lived experiences promote processes of self-reflection on what buen vivir really is or could be. We hold that the inclusive nature of buen vivir offers opportunities for diverse peoples to cohere around shared meanings of the 'good life,' while providing the freedom to live variations depending on social and ecological context.
    Regimes of justification : competing arguments and the construction of legitimacy in Dutch nature conservation practices
    Arts, Irma ; Buijs, A.E. ; Verschoor, G.M. - \ 2018
    Journal of Environmental Planning and Management 61 (2018)5-6. - ISSN 0964-0568 - p. 1070 - 1084.
    Legitimacy of environmental management and policies is an important topic in environmental research. Based on the notion of ‘regimes of justification’, we aim to analyse the dynamics in argumentations used to legitimize and de-legitimize Dutch nature conservation practices. Contrary to prior studies, we demonstrate how actors in two locations where environmental disputes arose showed little willingness to switch between arguments in order to reach a compromise. Instead, some actors constructed incompatibilities between arguments in order to delegitimize competing actors. Especially in the visioning phase, institutional actors emphasized technical efficiency, planning and global environmentalism, and arguments related to emotional accounts, inspiration and locality were de-legitimized. In the discussion, we argue that it is not the formal or informal inclusion of the actors in the process, but the construction of the legitimacy of their arguments that determines the inclusiveness and outcome of the process.
    Amphibious Encounters: Coral and People in Conservation Outreach in Indonesia
    Pauwelussen, A.P. ; Verschoor, Gerard - \ 2017
    Engaging Science, Technology, and Society 3 (2017). - ISSN 2413-8053 - p. 292 - 314.
    Drawing on long-term ethnographic research in Indonesia, this article describes a conservation outreach project that attempts to educate and convert local people into coral protectors. Both coral and the sea-dwelling Bajau people appear to be amphibious beings, moving between a changeable land-water interface, and between different, fluidly interwoven ontological constellations. We show that the failure of conservation organizations to recognize the ontologically ambiguous nature of “coral” and “people” translates to a breakdown of outreach goals. Mobilizing the concept of amphibiousness to engage this ambiguity and fluidity, we describe the moving land-water interface as the actual living environment for both coral and people. The notion of amphibiousness, we suggest, has practical and political value, in particular for reconsidering outreach and how it may be reframed as a process involving ontological dialogue. For conservation outreach to become seaworthy, it needs to cultivate an amphibious capacity, capable of moving in-between and relating partly overflowing ways of knowing and being. Providing room for ambiguity, thinking with amphibiousness furthermore encourages suspension of the (Western) tendency to explain the Other, to fix what does not add up. As such, it is of heuristic relevance for the on-going discussions of ontological multiplicity that have proliferated at the intersection between STS and anthropology.
    Evaluation of MACView® Portable Ethylene Postharvest Gas Analyser : Independent test of suitabilityand performance for use in horticultural settings
    Verschoor, Jan A. - \ 2017
    Wageningen : Wageningen Food & Biobased Research (Report / Wageningen Food & Biobased Research report 1753) - 24
    Hiemstra, J.A. - \ 2017
    Phytosanitary Measures Research Group Meeting 2017
    Verschoor, J.A. - \ 2017
    Phytosanitary Measures Research Group (a workgroup of the International Plant Protection Convention)
    Postharvest Technology Course
    Verschoor, Jan - \ 2017
    Haisheng Apple storage consultancy
    Verschoor, Jan - \ 2017
    2017 Huamentong Fruit Losses
    Verschoor, Jan - \ 2017
    Product Quality Measurements & Analysis - Quility of CA stored fruit
    Verschoor, Jan - \ 2017
    Postharvest Technology Course 2017
    Verschoor, J.A. - \ 2017
    Lisa Neven
    Verschoor, J.A. - \ 2017
    PlantgezondheidEvent 2017
    Verschoor, J.A. - \ 2017
    CATT in vaste planten ter bestrijding van aaltjes
    Dalfsen, P. van; Janssen, H. ; Verschoor, J.A. - \ 2017
    Randwijk : Wageningen University & Research, Bloembollen, Boomkwekerij & Fruit
    Risks of Plastic Debris : Unravelling Fact, Opinion, Perception, and Belief
    Koelmans, Albert A. ; Besseling, Ellen ; Foekema, Edwin ; Kooi, Merel ; Mintenig, Svenja ; Ossendorp, Bernadette C. ; Redondo-Hasselerharm, Paula E. ; Verschoor, Anja ; Wezel, Annemarie P. van; Scheffer, Marten - \ 2017
    Environmental Science and Technology 51 (2017)20. - ISSN 0013-936X - p. 11513 - 11519.
    Researcher and media alarms have caused plastic debris to be perceived as a major threat to humans and animals. However, although the waste of plastic in the environment is clearly undesirable for aesthetic and economic reasons, the actual environmental risks of different plastics and their associated chemicals remain largely unknown. Here we show how a systematic assessment of adverse outcome pathways based on ecologically relevant metrics for exposure and effect can bring risk assessment within reach. Results of such an assessment will help to respond to the current public worry in a balanced way and allow policy makers to take measures for scientifically sound reasons.
    Creating common ground : The role of Indigenous Peoples’ sacred natural sites in conservation practice, management and policy
    Verschuuren, Bas - \ 2017
    Wageningen University. Promotor(en): L.E. Visser, co-promotor(en): G.M. Verschoor. - Wageningen : Wageningen University - ISBN 9789463436496 - 219
    indigenous people - indigenous knowledge - historic sites - history - nature conservation - natural landscape - australia - ghana - guatemala - nature conservation policy - inheemse volkeren - inheemse kennis - historische plaatsen - geschiedenis - natuurbescherming - natuurlandschap - australië - ghana - guatemala - natuurbeleid

    In this thesis, I hold a plea for the recognition and integration of Indigenous people’s realities in conservation practice, management and policy related to their sacred natural sites. Sacred natural sites can be mountains, rivers, forests, trees and rocks that have special spiritual significance to indigenous peoples. To Indigenous peoples these places are not just part of their environment, culture and spirituality but they also form their worldviews and ethnicities.

    Based on my research on sacred natural sites, I look at how Indigenous people’s realities can be integrated into conservation approaches and how they lead to the co-creation of new forms of nature conservation. In doing so I focus on how a common ground is being created by Indigenous peoples and development and conservation actors. I argue that this common ground has the capacity to transform conservation practice, management and policy if different worldviews, including those of Indigenous peoples, are equally considered.

    The structure of this thesis represents my personal learning curve. It starts off with my earlier work developed as a conservationist with a natural sciences background and with many years of working experience in the field of international nature conservation. The Chapters gradually take on a sociological and anthropological angle, applying ethnographic research to conservation issues. As a result, the thesis represents the experience of a social conservation scientist doing applied and socially engaged research.

    The first part of the thesis is built upon conservation literature and draws on a multitude of case studies and previously published work. It presents an overview of the overall importance that indigenous sacred natural sites have to the current field of nature conservation and the main challenges and opportunities that these sites pose to conservationists.

    The second part of the thesis builds on case studies and applied ethnographic field research undertaken on conservation projects in North East Arnhem Land in Australia, Santa Cruz del Quiché in Guatemala and the Upper North-West Region in Ghana. In these locations, I have built up working relationships with local indigenous groups and the organisations that support them; respectively these are Yolŋu (since 2007), Maya (since 2012) and Dagara (since 2011).

    The qualitative research methods used throughout my research are based on ethnography, participatory research, observational research, co-creation of research, semi-structured interviews, focus groups, freelisting but also the field of social policy analysis, discourse analysis and literature research. They are particularly useful in situations where the research process contributes to finding solutions for concrete conservation problems with all parties involved.

    The conceptual framework brings together empirical studies and critical analyses of Indigenous sacred natural sites in different geographical, ecological, cultural and spiritual contexts. As these contexts vary across different places I studied the development of different common grounds between indigenous and non-indigenous actors in the specific locations. Eventually, I brought these studies together in an effort to distil common elements for the construction of a generic common ground.

    In the conceptual framework, worldviews and spirituality meet with conceptual areas such as ontological pluralism, biocultural diversity and rights-based approaches across geographical scales and governance levels. I argue that were they meet a common ground is created. I provide further analysis of the process of creating a common ground on the basis of the conceptual areas mentioned above, and draw conclusions that are relevant to furthering scientific debate in these areas as well to the field of conservation.

    Chapter 2 concludes that sacred natural sites are important to the conservation of nature and biodiversity because they form an informal network managed and governed by local Indigenous people. This network goes largely unrecognized by the international conservation community and local protected area managers and planners. The chapter presents ten challenges that sacred natural sites pose to the field of conservation and restoration of biological and cultural diversity.

    Chapter 3 takes examples of Indigenous worldviews and conservation practices from around the world to demonstrate that these form part of approaches that integrate biocultural values in nature conservation. I argue that in order to be effective and sustainable, nature conservation requires to be based on both science and culture, and combine scientific data on the natural world with experiential knowledge about nature of the social-cultural groups involved. The chapter concludes that, for management to be truly adaptive, it needs to respond to societal and cultural changes which can be achieved by enabling Indigenous people and local communities to guide conservation efforts.

    Chapter 4 addresses how the modern conservation movement can use biocultural conservation approaches to overcome disparities between the management and governance of nature and culture. In this discourse about biocultural conservation approaches, the spiritual and the sacred are essential to the conservation of an interconnected network of biocultural hotspots – sacred natural sites.

    Chapter 5 demonstrates the importance of Indigenous ontologies in cross-cultural coastal conservation management, particularly the development of locally relevant guidelines for fishers in North East Arnhem Land, Australia. I explore the ‘both ways’ approach adopted by the Dhimurru Aboriginal Corporation, and that guides collaboration between Yolŋu and non-Yolŋu. Disjunctures and synergies between the two ontologies are identified and I offer reflection on the role of the researcher in the cross-cultural co-production of guidelines for fishers and boaters.

    Chapter 6 analyses how spiritual leaders build common ground for community conservation of sacred natural sites in the face of neoliberalism in Ghana and Guatemala. The research demonstrates that, beyond rights-based approaches, a common ground is essential to developing feasible and acceptable solutions for the protection and conservation of sacred natural sites. I identify ‘ontological equity’ as an important principle for establishing this common ground. I then argue that neoliberal approaches to conservation and resource development are prejudiced because they ignore the principle of ontological equity and suppress lived realities of sacred natural sites and the existence of the wider spiritscape.

    Chapter 7 describes the emerging spaces in international policy and conservation practices as they manifest themselves in a series of conferences, the development of guidelines for protected area managers, and how these have worked to sensitize conservationists to sacred natural sites and their custodians. In connecting different conservation approaches from the local to the international level the chapter shows how a common ground is being created.

    The key findings of this thesis include several universal elements to the creation of a common ground: willingness to learn about other worldviews; application of participatory approaches and applied research; the use of cultural brokers; active processes of stakeholder engagement; agreement on governance arrangements and the adoption of ontological equity.

    I draw four conclusions derived from the main research results:

    1) Biocultural conservation approaches can enable the creation of a common ground, but they may also constrain Indigenous ontologies;

    2) Conservationists should learn from other worldviews and ontologies in order to improve the conservation of Indigenous sacred natural sites;

    3) Non-human agency and spiritual governance are under-recognised in the conservation of spiritscapes and sacred natural sites;

    4) Combining an ethnographic approach with an engaged and participatory research strategy is useful for considering multiple ontologies.

    The recommendations of this thesis could form part of a future research agenda for the development of a common ground between Indigenous people, conservationists, and development actors in relation to the conservation of Indigenous sacred natural sites. The main recommendation is that conservation and development actors should consider multiple ontologies when creating a common ground for the development of biocultural conservation approaches.

    Finding the food by hiding the gold : Andoque abundance, mining, and food in the Colombian Amazon
    Torres, Camilo ; Verschoor, Gerard - \ 2017
    In: Food, Agriculture and Social Change: The Everyday Vitality of Latin America / Sherwood, Stephen, Arce, Alberto, Paredes, Myriam, Routledge Taylor & Francis Group - ISBN 9781138214972 - p. 48 - 59.
    Food is important – but so is thinking about food through knowledge and experience. Food is an essential part of the “web of life,” but thinking about food has real consequences for the way it is grown, gathered, or procured. Scholarly and common ways of “thinking food” help shape systems of food production, distribution, and consumption, which have a bearing on the way societies are organized. As Carolan (2013: 413) notes, academic ways of thinking about food have undergone a number of “turns” over the years. Today we find ourselves in the midst of a new turn that stresses relationality and multiplicity while also emphasizing novel political and ontological practices.
    Challenging Current Knowledge on Amazonian Dark Earths : Indigenous Manioc Cultivation on Different Soils of the Colombian Amazon
    Peña-Venegas, Clara P. ; Verschoor, Gerard ; Stomph, Tjeerd Jan ; Struik, Paul C. - \ 2017
    Culture, Agriculture, Food and Environment 39 (2017)2. - ISSN 2153-9553 - p. 127 - 137.
    Amazonian soils - Floodplain agriculture - Indigenous manioc cultivation - Swidden management - Terra Preta

    Amazonian indigenous people grow manioc in landscapes of different agricultural potential, yet studies on indigenous manioc production on fertile soils are scarce. Non-indigenous communities grow specific manioc landraces on fertile Amazonian Dark Earths (ADE), but it is unknown whether indigenous farmers also do so. During 2 years, we studied manioc cultivation by five indigenous groups on different Amazonian soils using quantitative and qualitative methods. We found that environmental conditions, including soil quality, are less important in determining manioc diversity and agricultural strategies than socioeconomic and socio-cultural factors such as labor availability, labor organization, and culinary preferences.

    Visiedocument gebruik van biobeschikbaarheid in bodembeoordeling : mogelijkheden voor metalen in bodem en waterbodem
    Lijzen, J.P.A. ; Verschoor, A.J. ; Mesman, M. ; Boer, P.T. ; Osté, L. ; Römkens, P. - \ 2017
    Bilthoven : Rijksinstituut voor Volksgezondheid en Milieu (RIVM briefrapport 2015-0215) - 86
    Om te bepalen of de kwaliteit van een bodem geschikt is voor (her)gebruik, wordt een risicobeoordeling uitgevoerd. Daarmee wordt onder meer beoordeeld of de aanwezige metalen een risico vormen voor mens, plant en dier. Momenteel wordt hiervoor de totale concentratie van de aanwezige metalen gemeten. Bekend is echter dat niet al het aanwezige metaal schadelijke effecten veroorzaakt. Door de hoeveelheid metalen te bepalen die effecten kan veroorzaken, wordt de risicobeoordeling van metalen in land- en waterbodem verbeterd. Aanbevolen wordt een meetmethode met verdund salpeterzuur toe te passen waarmee dit kan. Het RIVM heeft een visiedocument opgesteld, waarin staat waar, hoe en waarom dit in het bodem- en waterbodembeleid mogelijk is.
    Amphibious anthropology : engaging with maritime worlds in Indonesia
    Pauwelussen, Annet P. - \ 2017
    Wageningen University. Promotor(en): Leontine Visser, co-promotor(en): Gerard Verschoor. - Wageningen : Wageningen University - ISBN 9789463430654 - 208
    cum laude

    This thesis explores how people live amphibiously in dynamic land-sea environments. It is based on eighteen months of ethnographic fieldwork (2011 – 2013) in the Makassar Strait maritime region in Indonesia: a complex and amphibious land-sea interface. In Western science little attention is given to how people live at sea. There is a general land bias, by which people are seen as primarily belonging to the land. Yet people do live at sea, or rather: in these dynamic land-sea environments. Engaging with these mobile and sea-based ways of life of maritime people provides not only a fuller understanding of how people relate to their environment, but , essentially, it also enables a critical reflection of land-biased assumptions in science and society.

    Anthropology, with its qualitative research methods is particularly suitable to do such in-depth and long-term engagement with other worlds. The research on which the thesis is based was carried out as a mobile ethnography, following people seawards, travelling with them for days to visit close family on faraway islands or joining them on their fishing and diving trips, including illegal fishers using bombs and cyanide poison on coral reefs. Also followed were the practices of marine conservation staff, as they organised field trips to fishing communities. These travels – described in the thesis – show how islands and marine spaces that are remote from the land, turn out to be regional hubs of oversees trade and family relations. From a sea-based perspective the Makassar Strait is a continuity of relations and movements flanked by land masses. This inverts the land-based perspective of the sea as an extension of the land by putting the sea centre stage.

    The Makassar Strait figures in this thesis as an active and moving world – or worlds – of human-marine relations to learn from and theorise about the notion of ontological flow: fluidity of being and moving in relation. Flow is both movement as a pattern of activity – the flowing – and that what flows; elements, matter and meaning in motion. The notion of worlds in flow has infused recent ontological debates in anthropological theory in which reality is assumed contingent, fluid and multiple – thereby revitalising the philosophical work of earlier thinkers, among whom Michel Serres and Gilles Deleuze. This way of thinking complexity and ontological fluidity is central to literature that has emerged out of the cross-fertilisation of Science and Technology Studies (STS), anthropology and philosophy. Despite differences, these studies share the objective to follow, engage with and translate how, in practice, material and semiotic realities come to be and matter – instead of developing a way to ‘access reality better’.

    The concept of ‘amphibiousness’ is mobilised to refer to living in and moving between different worlds that can intermingle but that cannot be reduced to each other. The concept is used to describe the human capacity to live in different worlds at the same time. This amphibious capacity is further elaborated 1) in terms of living in a hybrid land-water interface, 2) in terms of being able to move along with different understandings of the world, of reality, and 3) It refers to the methodology of the anthropologist who also needs to move in these worlds bodily and cognitively, to develop a sensitivity to and understanding of these different worlds. Amphibiousness captures the anthropological engagement with flow, multiplicity and otherness by way of moving between worlds in order to explore the moving interface between worlds, realities or ways of life that partly interact. The research question: How to grasp flow – the fluctuations of and between bodies, things or worlds in the making - conceptually and methodologically without reducing its vital mobility and fluidity? is elaborated in a methodological Chapter 2, and three research chapters (Chapter 3, Chapter 4, and Chapter 5) that each focus from a different angle on human-marine relations.

    The research exposes fundamentally different, and sometimes conflicting, ways in which people understand and experience their relation to the sea. These were not just different perspectives on one maritime reality, or world. These were inherently different understandings of reality, and different ways in which this reality is put into practice, in which worlds – plural – are being created and sustained. In anthropology we speak of ontological difference, because it concerns with (radically) different notions of wat exists, what is real, what matters and what entities participate in the reproduction of the world.

    Although these worlds are different – they cannot be reduced to each another - they are also not separated in any clear-cut way. They do flow into each other, as people, objects and ideas can amphibiously move in between. It is argued in this thesis that such amphibious translation is essential for more effective and equal collaboration in marine conservation. International environmental organisations insufficiently acknowledge (radically) different ways of doing and thinking human-marine relations. Disregarding these undermines the viability of conservation programs as it repeatedly leads to clashes between different ways in which maritime worlds are understood and organised in practice. To be effective, marine conservation needs to become amphibious; attentive to fundamentally different ways of understanding and experiencing the relationship between people and the sea, as well as the mobile practices of trade, fishing, travel and family affiliations through which these worlds are shaped beyond the borders of marine reserves.

    Chapter 2 intends to answer the question how to grasp environmental otherness – radically different ways of understanding and experiencing human-marine relations – in and through ethnography. Chapter 3 serves to provide some empirical grounding to show the relevancy and urgency of a paradigmatic shift in conservation thinking, finding ways to engaging mobile maritime people like the Bajau. The solution to the ‘participation problem’ in conservation will not lie in developing ways to make local people participate more in Western conservation schemes. What is needed is an ontological shift in conservation thinking itself. Chapter 4 describes a conservation outreach project that attempts to educate and convert local people into coral protectors. Both coral and the sea-dwelling Bajau people appear to be amphibious beings, moving between a changeable land-water interface, and between different, fluidly interwoven ontological constellations. Failure of conservation organisations to recognise the ontologically ambiguous nature of ‘coral’ and ‘people’ translates to a breakdown of outreach goals. Chapter 5 provides a case study of a dangerous and destructive fishing practice (cyanide fishing) by which fishers dive beyond the limits of what their body can take – and spirits allow, a practice that generates feeling of both fear and enjoyment as they experience a process of becoming permeable to fluids, spirits and currents penetrating or leaking out of their bodies. This chapter exposes how cyanide fishing sustains as a way of life, involving and producing affective relations.

    In Chapter 6 it is concluded how ontological multiplicity is of a heuristic and political relevance to social science, and anthropology in particular because it allows us to engage with radical difference – or the real on different terms – instead of explaining it away in our own terms. Engaging with such radical different is important because it allows to see the realities that systematically escape (scholarly) attention, yet affect the world nonetheless. This requires translation – the practice of relating different worlds, reals, repertoires or ways of life and bringing them into interaction – which is a process of, and a condition for, dialogue. The notion of amphibiousness has practical and political value, in particular for reconsidering conservation and development outreach and how it may be reframed as a process involving ontological dialogue. Providing room for ambiguity, thinking with amphibiousness furthermore encourages suspension of the (Western) tendency to explain the Other, to fix what does not add up.

    Towards transgressive learning through ontological politics : Answering the "call of the mountain" in a Colombian network of sustainability
    Chaves Villegas, Martha ; Macintyre, Thomas ; Verschoor, Gerard ; Wals, Arjen E.J. - \ 2017
    Sustainability 9 (2017)1. - ISSN 2071-1050
    Colombia - Narrative methods - Ontological politics - Sustainability - Transformative learning - Transgressive learning

    In line with the increasing calls for more transformative and transgressive learning in the context of sustainability studies, this article explores how encounters between different ontologies can lead to socio-ecological sustainability. With the dominant one-world universe increasingly being questioned by those who advocate the existence of many worlds-a so-called pluriverse-there lays the possibility of not only imagining other human-nature realities, but also engaging with them in practice. Moving towards an understanding of what happens when a multiplicity of worlds encounter one another, however, entails a sensitivity to the negotiations between often competing ontologies-or ontological politics. Based on an ethnographic methodology and narrative methods, data were collected from two consecutive intercultural gatherings called El Llamado de la Montaña (The Call of the Mountain), which take place for five days every year in different parts of Colombia. By actively participating in these gatherings of multiplicity, which address complex socio-ecological challenges such as food sovereignty and defence of territory, results show how encounters between different ontologies can result in transformative and potentially transgressive learning in terms of disrupting stubborn routines, norms and hegemonic powers which tend to accelerate unsustainability. Although we argue that a fundamental part of the wicked sustainability puzzle lies in supporting more relational ontologies, we note that such learning environments also lead to conflicts through inflexibility and (ab)use of power which must be addressed if sustained socio-ecological learning is to take place.

    Voorspelling bewaarkwaliteit (KwaliFruit)
    Schaik, A.C.R. van; Wenneker, M. ; Verschoor, J.A. - \ 2016
    Na-oogst kwaliteitsonderzoek KwaliFruit + GreenCHAINge
    Hogeveen-van Echtelt, Esther ; Schaik, A.C.R. van; Wenneker, M. ; Verschoor, J.A. - \ 2016
    Na-oogst kwaliteitsonderzoek Conference en Elstar: Projecten KwaliFruit + GreenCHAINge
    Hogeveen-van Echtelt, Esther ; Schaik, A.C.R. van; Wenneker, M. ; Verschoor, J.A. - \ 2016
    Answering the "Call of the Mountain" : co-creating sustainability through networks of change in Colombia
    Chaves Villegas, Martha - \ 2016
    Wageningen University. Promotor(en): Arjen Wals, co-promotor(en): Gerard Verschoor. - Wageningen : Wageningen University - ISBN 9789462577251 - 152
    sustainable development - sustainability - social networks - networks - communities - rural communities - change - social change - learning - colombia - south america - duurzame ontwikkeling - duurzaamheid (sustainability) - sociale netwerken - netwerken - gemeenschappen - plattelandsgemeenschappen - verandering - sociale verandering - leren - colombia - zuid-amerika

    In response to the age of the ‘anthropocene,’ as some authors are calling this epoch in which one single species is disrupting major natural systems (Steffen et al 2011), there are calls for more radical, learning-based sustainability that generates deep transformations in individuals and communities so as to transition towards a more reflexive and process-oriented society (Wals 2009, Sterling 2009). The principal contention of this thesis is that new social movements (NSM) of the network society (Castells 2012, Buechler 2016), based on integrated visions of sustainability, can provide platforms for bringing about transformative learning. This thesis is based on empirical research (2012-2016) into a fraction of such NSM named the Council of Sustainable Settlements of Latin America (C.A.S.A.). Comprising a diversity of members from Indigenous pueblos, afro-colombian communities, neo-rural settlements (ecovillages), Hare Krishna communities, campesino farmers, NGOs and urban peoples and initiatives, the C.A.S.A. network organizes intercultural exchanges where transformative learning can be traced. Through new forms of collective action centered on a plurality of ideas and practices, and with a strong focus on reflection and personal development, in such encounters through ‘ontological politics’, ‘optimal dissonance’ and ‘deep reflexivity and flexibility’ members are articulating new paradigms of alternative development and creating spaces for transformation. Yet, such learning processes are incredibly complex, and the value-action gap remains substantial in many cases. What this thesis has shown, however, is that by putting into practice principles of buen vivir and the pluriverse such as reconnecting to ancestral wisdom, acknowledging the other, questioning values of competition and consumerism, and forming new relations to place and territory, one begins to question one's own set of norms, and those of society. Ultimately, the C.A.S.A. network’s struggles, negotiations and learning processes remind us that global sustainability entails more than 'menus' of good practices but a plurality of solutions which include humans and non-humans, different ontologies, and even a multiplicity of worlds, in what is a tough but rewarding aula.

    CATT heeft potentie in strijd tegen aaltjes
    Dalfsen, P. van; Verschoor, J.A. - \ 2016
    De Boomkwekerij 2016 (2016)7. - ISSN 0923-2443
    Mundos equivocados: cuando la “abundancia” y la “carencia” se encuentran en la Amazonía colombiana
    Verschoor, G.M. ; Torres, C. - \ 2016
    Revista de Ciencias Sociales Quito. Ecuador 20 (2016)54. - ISSN 1390-1249 - p. 71 - 86.
    Este artículo describe y analiza los efectos de la minería artesanal que involucra a comunidades Andoque del Resguardo Aduche (Amazonía colombiana) en su seguridad alimentaria. En términos analíticos, el punto de partida es la existencia de diferentes perspectivas sobre las actividades de las poblaciones indígenas. Algunas de estas –las que se basan en la noción de “carencia”– distorsionan los ensamblajes en los que participan las comunidades indígenas, involucrándolas en una disyuntiva que choca contra su concepto de “abundancia”. Lo paradójico de este caso es que en un mundo de “abundancia amazónica” se inserta un modelo deficitario basado en la extracción del oro, en donde se integran elementos exógenos que dificultan el reensamblaje inicial. Desde una perspectiva alejada de la unicidad cultural, esta investigación aborda la multiplicidad de las prácticas y realidades donde los diversos actores enfrentan dilemas de uso de los recursos comunes, se integran al “fácil” acceso al dinero y en la que se desfigura la cosmovisión local que requiere que “no se debe tocar lo que no ilumina el sol”.
    Classification and Use of Natural and Anthropogenic Soils by Indigenous Communities of the Upper Amazon Region of Colombia
    Peña-Venegas, C.P. ; Stomph, T.J. ; Verschoor, G. ; Echeverri, J.A. ; Struik, P.C. - \ 2016
    Human Ecology 44 (2016)1. - ISSN 0300-7839 - p. 1 - 15.
    Amazonian Dark Earths - Colombia - Indigenous communities - Manioc - Soil

    Outsiders often oversimplify Amazon soil use by assuming that abundantly available natural soils are poorly suited to agriculture and that sporadic anthropogenic soils are agriculturally productive. Local perceptions about the potentials and limitations of soils probably differ, but information on these perceptions is scarce. We therefore examined how four indigenous communities in the Middle Caquetá River region in the Colombian Amazon classify and use natural and anthropogenic soils. The study was framed in ethnopedology: local classifications, preferences, rankings, and soil uses were recorded through interviews and field observations. These communities recognized nine soils varying in suitability for agriculture. They identified anthropogenic soils as most suitable for agriculture, but only one group used them predominantly for their swiddens. As these communities did not perceive soil nutrient status as limiting, they did not base crop-site selection on soil fertility or on the interplay between soil quality and performance of manioc genetic resources.

    CATT : A new and non-chemical pest and nematode control method in strawberry planting stock
    Kruistum, G. Van; Evenhuis, A. ; Hoek, J. ; Kastelein, P. ; Wolf, J.M. Van Der; Verschoor, J.A. - \ 2015
    Acta Horticulturae 1105 (2015). - ISSN 0567-7572 - p. 189 - 196.
    Disinfection - Fragaria × ananassa - Frigo plants - Meloidogyne hapla - Nurseries - Phytonemus pallidus - Xanthomonas fragariae

    As an alternative to MeBr fumigation, a 48 h controlled atmosphere temperature treatment (CATT) was developed and scaled up by Wageningen UR in cooperation with the Dutch plant propagating association Plantum. This results in an excellent deinfestation and 99.8% mortality of the strawberry tarsonemid mite (Phytonemus pallidus). This non-chemical and sustainable method provides a healthy production of high quality strawberry runners in the field. From 2009, CATT was scaled up to a commercial level and widely applied by Dutch nurseries. In 2011, this CATT method was successfully modified to also eradicate the root knot nematode Meloidogyne hapla (>99.7% mortality), which was not effectively controlled by MeBr fumigation. For an effective killing of the root knot nematodes, temperature must be raised to 40°C. In several experiments, the optimum conditions for high mortality of both tarsonemids and nematodes were studied. An adapted version of CATT was developed of 20 h at a temperature of 35°C and 50% CO2 followed by 20 h at a temperature of 40°C. In 2012, this adapted CATT was successfully upgraded and tested under field conditions. Additional research in 2013 led to the conclusion that cross infection of plants by the bacterial Q-disease (Xanthomonas fragariae) during CATT treatment is unlikely.

    Application of the Benthic Ecosystem Quality Index 2 to benthos in Dutch transitional and coastal waters
    Loon, W.M.G.M. van; Boon, A.R. ; Gittenberger, A. ; Walvoort, D.J.J. ; Lavaleye, M. ; Duineveld, G.C.A. ; Verschoor, A.J. - \ 2015
    Journal of Sea Research 103 (2015). - ISSN 1385-1101 - p. 1 - 13.
    Benthic invertebrates - BEQI2 - Dutch transitional and coastal waters - Multi-metric index - Water framework directive

    The Benthic Ecosystem Quality Index 2 (BEQI2) is the Dutch multi-metric index (MMI) for assessing the status and trend of benthic invertebrates in transitional and coastal waters for the Water Framework Directive (WFD). It contains the same indicators, i.e. species richness, Shannon index and AMBI, as in the multivariate m-AMBI. The latter MMI has been adopted by several European countries in the context of WFD implementation. In contrast to m-AMBI, the BEQI2 calculation procedure has been strongly simplified and consists of two steps, i.e. the separate indicator values are normalized using their long-term reference values resulting in three Ecological Quality Ratios (EQRs), which are subsequently averaged to give one BEQI2 value. Using this method only small numbers of samples need to be analysed by Dutch benthos laboratories annually, without the necessity to co-analyse a larger historical dataset. BEQI2 EQR values appeared to correlate quantitatively very well with m-AMBI EQR values. In addition, a data pooling procedure has been added to the BEQI2 tool which enables the pooling of small core samples (0.01-0.025m2) into larger standardized data pools of 0.1m2 in order to meet the data requirements of the AMBI indicator and to obtain comparable reference values. Furthermore, the BEQI2 tool automatically and efficiently converts species synonym names into standardized species names. The BEQI2 tool has been applied to all Dutch benthos data monitored by Rijkswaterstaat in the period of 1991-2010 in the transitional and coastal waters and salt lakes and these results are reported here for the first time. Reference values for species richness and Shannon index (99 percentile values) and AMBI reference values (1 percentile values) were estimated for all water body-ecotopes and are discussed. BEQI2 results for all these water bodies are discussed in view of natural and human pressures. The pressure sensitivity of the BEQI2 for sewage and dredging/dumping, via the state variables oxygen and suspended matter respectively, was demonstrated.

    KwaliFruit, Kwaliteitsvoorspelling bewaring Elstar en Conference
    Schaik, A.C.R. van; Wenneker, M. ; Verschoor, J.A. - \ 2015
    Op naar een aaltjesvrije vaste plantenteelt : Kennis en ervaringen uit een praktijknetwerk
    Dalfsen, P. van; Verschoor, J.A. - \ 2015
    Praktijkonderzoek Plant & Omgeving, Business Unit Bloembollen, Boomkwekerij & Fruit - 19 p.
    Xanthomonas geen beletsel voor CATT
    Evenhuis, A. ; Kastelein, P. ; Kruistum, G. van; Verschoor, J.A. ; Wolf, J.M. van der - \ 2015 (2015). - p. 14 - 14.
    Controlled Atmosphere Temperature Treatment : Non-chemical (quarantine) pest control in fresh plant products
    Verschoor, J.A. ; Otma, E.C. ; Qiu, Y.T. ; Kruistum, G. Van; Hoek, J. - \ 2015
    Acta Horticulturae 1071 (2015). - ISSN 0567-7572 - p. 253 - 258.
    Insects - Nematodes - Phytosanitation

    Insects, nematodes and mites that damage postharvest plant products can cause severe quality losses or trade restrictions in case of quarantine organisms. With the ban of the ozone depleting methyl bromide (MeBr), the most widely used chemical for phytosanitary treatments, effective and sustainable alternatives are required. A physical method, Controlled Atmosphere Temperature Treatment (CATT) can be a sustainable alternative for the control of pests on living plant products. Optimising CA-conditions besides temperature and exposure time can help in developing successful applications. In The Netherlands, a successful application to disinfest strawberry (Fragaria × ananassa) planting material from strawberry tarsonemid mite (Phytonemus pallidus) or plant parasitic nematodes Meloidogyne hapla was developed and implemented in practice. Initial tests with a number of other potential quarantine plant-pest combinations showed promising results of CATT.

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