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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    Efficacies of bacterial and fungal isolates in biocontrol of Botrytis cinerea and Pseudomonas syringae pv. tomato and growth promotion in tomato do not correlate
    Köhl, J. ; Vasconcelos de Medeiros, Flavio ; Plas, C.H. ; Haas, B.H. de; Bosch, G.B.M. van den - \ 2020
    Biological Control 150 (2020). - ISSN 1049-9644
    biological control - Antagonist - Bioassay - Grey mold - Bacterial spot - Solanum lycopersicon
    There is a need to develop more biological control agents to fulfil the increasing demand for biological crop protection. Testing for consistent efficacy in disease control under the relevant range of environmental conditions is one of the most demanding steps during screening programs. Bioassays were conducted to target three major diseases of tomato, stem canker caused by Botrytis cinerea, leaf spot caused by B. cinerea, and bacterial spot caused by Pseudomonas syringae pv. tomato, and to assess possible growth promotion of tomato seedlings. Nine quantitative screening approaches were analyzed for a test panel of approximately 100 isolates of bacteria and fungi, all obtained from tomato, and several known antagonists as reference isolates. Even with such a limited number of isolates promising antagonists, partly not yet described as antagonists, could be selected for control of the targeted diseases when labor and resource demanding in planta bioassays had been applied. Also some promising isolates enhancing seedling development could be identified. Independent screening assays for the different traits were needed since no correlation between the different traits were found. Attempts to simplify screening assays to high-throughput systems failed since there were no positive correlations with in planta bioassays. In conclusion, the often suggested first screening rounds using in vitro tests for huge numbers of isolates followed by in planta testing of a selected group of candidates, e.g. those with high in vitro production of certain secondary metabolites or biosurfactants, may not exploit the entire potential of antagonists. Especially antagonists combining various modes of action may be excluded by in vitro screening with a bias on a specific mode of action. Therefore, independent in planta assays are proposed to screen against different pathogens and for growth promotion.
    Conflicten over natuurbeheer : Wat kenmerkt deze? Wat kunnen we eruit leren?
    Haas, Wim de - \ 2020
    Wageningen : Wettelijke Onderzoektaken Natuur & Milieu (WOt-paper 51) - 7
    Transition pathways - analyzing transitions in food systems : A synthesis of seven case studies
    Dengerink, Just ; Roo, Nina de; Dijkshoorn-Dekker, Marijke ; Bos, Bram ; Hetterscheid, Bas ; Kraan, Marloes ; Bonnand, Johann ; Haas, Wim de; Linderhof, Vincent - \ 2020
    Wageningen : Stichting Wageningen Research, Wageningen Plant Research, Business Unit Field Crops (Report / Stichting Wageningen Research, Wageningen Plant Research, Business Unit FieldCrops WPR-838) - 55
    Assessing the activity of individual group-housed broilers throughout life using a passive radio frequency identification system—a validation study
    Sluis, Malou van der; Haas, Yvette de; Klerk, Britt de; Rodenburg, T.B. ; Ellen, Esther D. - \ 2020
    Sensors 20 (2020)13. - ISSN 1424-8220 - p. 1 - 21.
    Activity - Broilers - Radio frequency identification - Tracking - Ultra-wideband - Video

    Individual data are valuable for assessing the health, welfare and performance of broilers. In particular, data on the first few days of life are needed to study the predictive value of traits recorded early in life for later life performance. However, broilers are generally kept in groups, which hampers individual identification and monitoring of animals. Sensor technologies may aid in identifying and monitoring individual animals. In this study, a passive radio frequency identification (RFID) system was implemented to record broiler activity, in combination with traditional video recordings. The two main objectives were 1) to validate the output of the RFID system by comparing it to the recorded locations on video, and 2) to assess whether the number of antennas visited per unit time could serve as a measure of activity, by comparing it to the distance recorded on video and to the distance moved as recorded using a validated ultra-wideband (UWB) tracking system. The locations recorded by the RFID system exactly matched the video in 62.5% of the cases, and in 99.2% of the cases when allowing for a deviation of one antenna grid cell. There were moderately strong Spearman rank correlations between the distance recorded with the RFID system and the distance recorded from video (rs = 0.82) and between UWB and RFID (rs = 0.70) in approximately one-hour recordings, indicating that the RFID system can adequately track relative individual broiler activity, i.e., the activity level of a broiler in comparison to its group members. As the RFID tags are small and lightweight, the RFID system is well suited for monitoring the individual activity of group-housed broilers throughout life.

    Draft genome sequences of three isolates of golubevia sp. basidiomycete fungi isolated from powdery mildew pustules
    Russ, Lina ; Warris, Sven ; Lombaers-Van der Plas, Carin ; Groenenboom-De Haas, Lia H. ; Cordewener, Jan H.G. ; Schijlen, Elio ; Köhl, Jürgen - \ 2020
    Microbiology Resource Announcements 9 (2020)23. - ISSN 2576-098X

    The genomes of three Golubevia isolates (BC0812, BC0850, and BC0902) that have been shown to reduce conidiation of Blumeria graminis f. sp. tritici were sequenced using a dual-platform approach. The assembled genomes will help to elucidate the molecular mechanisms underlying the biocontrol effect of this understudied group.

    Transition pathways - contours of an analytical framework
    Elzen, Boelie ; Haas, Wim de; Wigboldus, Seerp ; Bos, Bram ; Dijkshoorn-Dekker, Marijke - \ 2020
    Wageningen : Stichting Wageningen Research, Wageningen Plant Research, Business Unit Field Crops (Report WPR 839) - 30
    Can greenhouse gases in breath be used to genetically improve feed efficiency of dairy cows?
    Difford, G.F. ; Løvendahl, P. ; Veerkamp, R.F. ; Bovenhuis, H. ; Visker, M.H.P.W. ; Lassen, J. ; Haas, Y. de - \ 2020
    Journal of Dairy Science 103 (2020)3. - ISSN 0022-0302 - p. 2442 - 2459.
    breath gas measurement - carbon dioxide - feed efficiency - methane - residual feed intake

    There is considerable interest in improving feed utilization of dairy cattle while limiting losses to the environment (i.e., greenhouse gases, GHG). To breed for feed-efficient or climate-friendly cattle, it is first necessary to obtain accurate estimates of genetic parameters and correlations of feed intake, greenhouse gases, and production traits. Reducing dry matter take (DMI) requirements while maintaining production has high economic value to farmers, but DMI is costly to record and thus limited to small research or nucleus herds. Conversely, enteric methane (CH4) currently has no economic value, is also costly to record, and is limited to small experimental trials. However, breath gas concentrations of methane (CH4c) and carbon dioxide (CO2c) are relatively cheap to measure at high throughput under commercial conditions by installing sniffers in automated milking stations. The objective of this study was to assess the genetic correlations between DMI, body weight (BW), fat- and protein-corrected milk yield (FPCM), and GHG-related traits: CH4c and CO2c from Denmark (DNK) and the Netherlands (NLD). A second objective was to assess the genetic potential for improving feed efficiency and the added benefits of using CH4c and CO2c as indicators. Feed intake data were available on 703 primiparous cows in DNK and 524 in NLD; CH4c and CO2c records were available on 434 primiparous cows in DNK and 656 in NLD. The GHG-related traits were heritable (e.g., CH4c h2: DNK = 0.26, NLD = 0.15) but were differentially genetically correlated with DMI and feed efficiency in both magnitude and sign, depending on the population and the definition of feed efficiency. Across feed efficiency traits and DMI, having bulls with 100 daughters with FPCM, BW, and GHG traits resulted in sufficiently high accuracy to almost negate the need for DMI records. Despite differences in genetic correlation structure, the relatively cheap GHG-related traits showed considerable potential for improving the accuracy of breeding values of highly valuable feed intake and feed efficiency traits.

    Real-Time Visualization of Methane Emission at Commercial Dairy Farms
    Schokker, Dirkjan ; Mollenhorst, Herman ; Seigers, Gerrit ; Haas, Yvette De; Veerkamp, Roel F. ; Kamphuis, Claudia - \ 2020
    In: International Symposium on Environmental Software Systems (ISESS 2020) Wageningen : Springer (IFIP Advances in Information and Communication Technology ) - ISBN 9783030398149 - p. 194 - 200.
    The Dutch government has set an objective to reduce greenhouse gasses (GHG) emissions to 116 Mton CO2-equivalent in 2030. The agriculture sector aims for 11–23 Mton of GHG emission by 2050 and thus contributes to this objective. For this sector, the major contributor to the GHG emission in the Netherlands is the dairy sector. Before any mitigation strategies can be enrolled, some key facts need to be measured regarding the GHG emission on a farm. One of these key facts is the establishment of the baseline of GHG emission on a farm (and per cow). For this, we previously have built an infrastructure to measure and collect methane and carbon dioxide (near) real-time on a farm. The next challenges, addressed in the current study, were to (1) combine the private methane data, collected real-time through the infrastructure, with open source weather information, and (2) visualize both data streams for farmers, by developing an application that can be viewed on a web or mobile phone platform.
    Development and evaluation of two TaqMan assays for generic detection of Dickeya species
    Zijlstra, Carolien ; Haas, Lia Groenenboom De; Krijger, Marjon ; Verstappen, Els ; Warris, Sven ; Haan, Eisse de; Wolf, Jan van der - \ 2020
    European Journal of Plant Pathology 156 (2020). - ISSN 0929-1873 - p. 311 - 316.
    Accuracy - Blackleg - Diagnostics - Refused sample material - Seed potato - Sensitivity - Specificity

    Two TaqMan assays were developed for generic detection of Dickeya species in plant material. The assays enabled detection of all strains of D. chrysanthemi, D. dadantii, D. dianthicola, D. solani and D. zeae tested, but only weak reactions were found with strains of D. paradisiaca. The assays enabled detection of as low as 100 fg of target DNA in a background of potato DNA. The assays were evaluated with DNA extracted from potato tuber extracts, in which different Dickeya species can be present. Results of both assays were highly similar indicating that they can be used reliably in potato seed testing programs.

    Contribution of animal breeding to reduce environmental impact of animal products
    Mollenhorst, H. ; Haas, Y. de - \ 2019
    - 317 p.
    ISSN/ISBN: 1382-6077
    Publisher: Wageningen Academic Publishers, Wageningen
    Natuur in conflict: botsende waarden, waarheden en belangen in het natuurbeheer
    Haas, W. de; Donders, J.L.M. ; Mattijssen, T.K.M. - \ 2019
    Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-technical report 163) - 108
    Conservation management can sometimes lead to bitter conflicts. The aim of this project is to get a better understanding of how and why this happens. From an inventory of conservation conflicts, two were selected for further study. The conflict in the Amsterdamse Waterleidingduinen (a protected area for the abstraction of drinking water) concerned the management hunting of fallow deer. This conflict was finally settled by legal process. In Salland the conflict was about the conversion of forest into an open landscape. The forest clearance was limited in the wake of a nationwide discussion about the climate change impact. Important lessons are: think in terms of dilemmas, not solutions; bring parties into direct communication; and listen to people who have local knowledge. In general, conflicts should not be seen as negative phenomena. They help to bring the issues to light and in the long term this contributes to the growth of society.
    Circulaire systemen
    Bos, Harriëtte ; Groenestijn, John van; Harmsen, Paulien ; Hugenholtz, Jeroen ; Appelmans, Wilfred ; Jetten, Jan ; Bussmann, Pauil ; Bon, Jeroen van; Burgering, Maurits ; Verdoes, Nico ; Groenestein, Karin ; Duinkerken, Gert van; Fels-Klerx, Ine van der; Schans, Milou van de; Gerrits, Elise ; Schoumans, Oscar ; Haas, Wim de; Regelink, Inge ; Stuiver, Marian ; Bakker, Sjaak ; Dijk, Wim van; Visser, Saskia - \ 2019
    Wageningen : Wageningen University & Research - 41
    On-farm automated tracking of group-housed poultry
    Ellen, E.D. ; Sluis, M. van der; Klerk, B. de; Haas, Y. de; Hijink, Thijme ; Rodenburg, T.B. - \ 2019
    In: Book of abstracts of the 70th Annual Meeting of the European Federation of Animal Science (EAAP). - Wageningen Academic Publishers (Book of Abstracts ) - ISBN 9789086863396 - p. 136 - 136.
    Production animals, including poultry, are increasingly kept in groups, making identication and tracking of individual animals challenging. Often video analyses are used, but these are time-consuming and prone to human error. Therefore, automated systems for monitoring individual animals are desired. One possible approach is the implementation of an ultra-wideband (UWB) system to track individual animals. A previous study implemented an UWB system for laying hens in a research setting. Hens were tted with an UWB tag in a small backpack and, using stationary sensing beacons, the location of each bird could be determined. Compared to video tracking of individual birds, the UWB system was shown to be capable of detecting the bird’s location with 85% accuracy. In the current study, the system was applied on a broiler farm to assess its on-farm applicability. At approximately 14 days of age, broilers were tted with an UWB tag. Twelve birds were tracked with the UWB system on nineteen consecutive days, for one hour each day. Distances moved according to the UWB system were compared to those found on video and a moderately strong correlation between the UWB system and video tracking was found (Repeated measures correlation, r=0.71, P<0.0005). Furthermore, individual levels of activity were assessed using this setup. 137 birds from different genetic crosses were tracked near-continuously for seventeen consecutive days. First results indicate that for all crosses, the UWB system was found to be capable of detecting a decrease in activity over time. Overall, the UWB system appears well-suited for tracking of broilers. However, the UWB tags are relatively large. Therefore, tracking and monitoring of young broilers is not possible. Current work is focussing on implementing a passive radio frequency identication system, with smaller tags. Possibly, this system can track individual activity of broiler chickens throughout their life.
    Developing proxies for resilience and efficiency with at-market sensor technologies
    Kamphuis, C. ; Haas, Y. de; Friggens, N.C. ; Ouweltjes, W. - \ 2019
    - 10 p.
    At-market sensor technologies to develop proxies for resilience and efficiency in dairy cows
    Kamphuis, C. ; Haas, Y. de; Ouweltjes, W. - \ 2019
    In: Proceedings of the 2nd International Precision Dairy Farming Conference. - University of Minnesota - p. 11 - 12.
    Potential of DNA pooling for the inclusion of commercial slaughterhouse data in genetic improvement
    Aldridge, M.N. ; Klerk, B. de; Haas, Y. de; Greef, K.H. de - \ 2019
    In: Book of Abstracts of the 70th Annual Meeting of the European Federation of Animal Science. - Wageningen Academic Publishers (EAAP Book of Abstracts 25) - p. 289 - 289.
    Rural livelihoods and agricultural commercialization in colonial Uganda: conjunctures of external influences and local realities
    Haas, Michiel De - \ 2019
    European Review of Economic History (2019). - ISSN 1361-4916
    Positioneren in meervoudigheid : Omgaan met een diversiteit aan frames
    Haas, W. de; Donders, J.L.M. - \ 2019
    Moving beyond colonial control? Economic forces and shifting migration from Ruanda-Urundi to Buganda, 1920–60
    Haas, Michiel De - \ 2019
    Journal of African History 60 (2019)3. - ISSN 0021-8537 - p. 379 - 406.
    Migration was a crucial component of the spatially uneven formation of labour markets and export-oriented economies in colonial Africa. Much of this mobility was initiated by migrants themselves rather than by colonial authorities. Building on analytical concepts from economic history and migration theory, this study explains the changing composition and magnitude of one such uncontrolled migration flow, from Ruanda-Urundi to Buganda. Migrants’ mobility choices – when to migrate, for how long, and with whom – proved highly responsive to shifting economic opportunity structures on the sending and receiving ends. Initially, large differences in terms of land and labour endowments, socio-economic structures, and colonial interventions, combined with substantial scope for price arbitrage, created large spatial inequalities of opportunity and strong incentives for circular male labour migration. Over time, however, migration contracted as opportunities in Ruanda-Urundi and Uganda converged, not in the least as a result of large-scale mobility itself.

    Biodiversiteit & Kringlooplandbouw
    Doorn, Anne van; Vet, Louise ; Sukkel, Wijnand ; Melman, Dick ; Migchels, Gerard ; Lotz, Bert ; Vogelzang, Theo ; Westerink, Judith ; Haas, Wim de - \ 2019
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