Wageningen UR Plant Research International

AA, Netherlands

Wageningen UR Plant Research International

AA, Netherlands

Time filter

Source Type

Kohl J.,Wageningen UR Plant Research International | de Jong P.-F.,WageningenUR Applied Plant Research PPO Fruit | Kastelein P.,Wageningen UR Plant Research International | Groenenboom-de Haas B.H.,Wageningen UR Plant Research International | And 3 more authors.
European Journal of Plant Pathology | Year: 2013

Brown spot disease on pear caused by Stemphylium vesicarium may affect leaves and fruits. Inoculum sources present on orchard floors play an important role in the epidemiology of pear brown spot. The pathogen can overwinter on plant residues and multiply and spread on the residues during the growing season. In the Netherlands, brown spot characteristically occurs only in a fraction of the orchards per season. Until now, no tools are available for Dutch pear growers to predict the risk of brown spot in specific orchards. As a consequence, preventive fungicide sprayings are common. The concentration of DNA of pear-pathogenic S. vesicarium was quantified by a specific TaqMan-PCR assay for various types of plant residues present on orchard floors to evaluate their importance as potential inoculum source. The pathogen was often found in residues of pear leaves, grasses and weeds, but only occasionally in mummies and prunings. Studies of the population dynamics showed that S. vesicarium decreased in dead pear leaves during early winter whereas pathogen populations developed with irregular pattern during the growing season on residues of weeds and grasses. Based on DNA concentrations of S. vesicarium in plant residue samples taken in 78 to 106 orchards in the springs of 2010, 2011 and 2012, the risk of brown spot development could be predicted for individual orchards. Such a risk prediction will allow growers to adapt their fungicide spray schedules to avoid unnecessary sprays in low-risk orchards. © 2013 KNPV.


Kohl J.,Wageningen UR Plant Research International | Lombaers C.,Wageningen UR Plant Research International | Moretti A.,National Research Council Italy | Bandyopadhyay R.,International Institute Of Tropical Agriculture | And 2 more authors.
Biological Control | Year: 2015

Pink ear rot of maize caused by Fusarium verticillioides, Fusarium proliferatum and Fusarium graminearum can lead to severe yield losses and contamination of grain with a range of mycotoxins. Maize stalks colonized by Fusarium spp. are the main primary inoculum source for Fusarium incited epidemics in maize or other susceptible crops grown in rotation.The colonization of individual maize stalks originating from fields in The Netherlands, Italy and Nigeria by Fusarium spp. was quantified using specific TaqMan-PCR assays. Highest values were found for F. graminearum and Fusarium avenaceum in Dutch samples, for F. graminearum and FUM producing species (. F. verticillioides and F. proliferatum) in Italian samples and FUM producing Fusarium spp. in Nigerian samples. The increase in Fusarium spp. colonization under field conditions during a period of 3-6. months after harvest of the maize crops varied considerably between individual stalks. The fungal and bacterial diversity was analyzed for sub-sets of stalks with high versus low increase of Fusarium colonization. Bacterial taxonomic groups such as Bacillus, Curtobacterium, Erwinia, Flavobacterium, Novosphingobium, Pantoea, Sphingomonas, Rahnella and Staphylococcus and fungal taxonomic groups such as Acremomium sp., Cryptococcus flavescens, Cryptococcus zeae, Leptosphaeria sp. and Microdochium bolleyi were more abundant in the stalks with lower increase in pathogen colonization. Such fungal and bacterial groups associated with 'suppressive stalks' may be antagonistic to Fusarium spp. and a source of candidate strains for the selection of new biological control agents. © 2015 Elsevier Inc.


PubMed | University of Wisconsin - Madison, University of Kaiserslautern, Hill International, Syngenta and 4 more.
Type: Journal Article | Journal: Molecular plant pathology | Year: 2016

Following earlier incomplete and fragmented versions of a genome sequence for the grey mould Botrytis cinerea, a gapless, near-finished genome sequence for B. cinerea strain B05.10 is reported. The assembly comprised 18 chromosomes and was confirmed by an optical map and a genetic map based on approximately 75 000 single nucleotide polymorphism (SNP) markers. All chromosomes contained fully assembled centromeric regions, and 10 chromosomes had telomeres on both ends. The genetic map consisted of 4153 cM and a comparison of the genetic distances with the physical distances identified 40 recombination hotspots. The linkage map also identified two mutations, located in the previously described genes Bos1 and BcsdhB, that conferred resistance to the fungicides boscalid and iprodione. The genome was predicted to encode 11 701 proteins. RNAseq data from >20 different samples were used to validate and improve gene models. Manual curation of chromosome 1 revealed interesting features, such as the occurrence of a dicistronic transcript and fully overlapping genes in opposite orientations, as well as many spliced antisense transcripts. Manual curation also revealed that the untranslated regions (UTRs) of genes can be complex and long, with many UTRs exceeding lengths of 1 kb and possessing multiple introns. Community annotation is in progress.


Kohl J.,Wageningen UR Plant Research International | Scheer C.,Foundation Kompetenzzentrum Obstbau Bodensee | Holb I.J.,Debrecen University | Holb I.J.,Hungarian Academy of Sciences | And 2 more authors.
Plant Disease | Year: 2015

Apple scab, caused by Venturia inaequalis, is the most important disease in apple production, reducing yield and quality of fruit. Control of apple scab in commercial orchards currently depends on multiple applications of fungicides. The potential of the antagonistic isolate Cladosporium cladosporioides H39, originating from a sporulating colony of V. inaequalis, to control apple scab development was tested in eight trials during 2 years in orchards in Eperjeske (Hungary), Dabrowice (Poland), and Bavendorf (Germany) planted with different cultivars. Treatments were conducted as calendar sprays or after infection periods. Additional trials in an orchard in Randwijk (The Netherlands) focused on the effect of timing of antagonist application before or after infection periods. The overall results of the field trials consistently showed—for the first time—that stand-alone applications of the antagonist C. cladosporioides H39 can reduce apple scab in leaves and fruit. This was demonstrated in an organic growing system as well as in conventional orchards by spray schedules applied during the primary or the summer season. In both systems, the same control levels could be reached as with common fungicide schedules. Efficacies reached 42 to 98% on leaf scab incidence and 41 to 94% on fruit scab. The antagonist was also effective if applied one or even several days (equivalent to approximately 300 to 2,000 degree h) after infection events in several field trials and a trial conducted in Randwijk with single-spray applications at different intervals before or after infection events. Better understanding of the biology of the antagonist will help to further exploit its use in apple scab control. © 2015 The American Phytopathological Society.


Aarts H.F.M.,Wageningen UR Plant Research International | Humphreys J.,Teagasc | Le Gall A.,Institute Of Lelevage
Journal of Agricultural Science | Year: 2014

Substantial improvements of agricultural systems are necessary to meet the future requirements of humanity. However, current agricultural knowledge and information systems are generally not well suited to meet the necessary improvements in productivity and sustainability. For more effective application of research output, research producers and research consumers should not be considered as separate individuals in the knowledge chain but as collaborating partners creating synergy. The current paper investigates the relationships between scientists and stakeholders and identifies approaches to increase the effectiveness of their communication. On-farm research has proven to be an effective means of improving exploitation of research output at farm level because it connects all relevant partners in the process. Furthermore, pilot farms can act as an effective platform for communication and dissemination. Regional networks of pilot farms should be established and connected across regions. © Cambridge University Press 2014.


PubMed | Wageningen UR Plant Research International, Teagasc and Institute Of Lelevage
Type: Journal Article | Journal: The Journal of agricultural science | Year: 2015

Substantial improvements of agricultural systems are necessary to meet the future requirements of humanity. However, current agricultural knowledge and information systems are generally not well suited to meet the necessary improvements in productivity and sustainability. For more effective application of research output, research producers and research consumers should not be considered as separate individuals in the knowledge chain but as collaborating partners creating synergy. The current paper investigates the relationships between scientists and stakeholders and identifies approaches to increase the effectiveness of their communication. On-farm research has proven to be an effective means of improving exploitation of research output at farm level because it connects all relevant partners in the process. Furthermore, pilot farms can act as an effective platform for communication and dissemination. Regional networks of pilot farms should be established and connected across regions.


Ponsone M.L.,Instituto Nacional de Tecnologia Agropecuaria | Nally M.C.,National University of San Juan | Chiotta M.L.,National University of Rio Cuarto | Combina M.,Instituto Nacional de Tecnologia Agropecuaria | And 2 more authors.
Biological Control | Year: 2016

The efficacy of two strains of Lanchancea thermotolerans in preventing the growth and ochratoxin A (OTA) accumulation of ochratoxigenic fungi under greenhouse and field conditions were evaluated during three consecutive year trials. The data from this study showed that both yeast strains were able to control Aspergillus section Nigri species ochratoxin A accumulation in wine grapes at harvest stage. The inhibitory effects were dependent on the ochratoxigenic species, yeast strains, and year analyzed. Over all conditions assayed, ochratoxin A accumulation was reduced from 27% to 100%, depending on the conditions evaluated. These results are promising for future development of a bio-pesticide. © 2016


Palazzini J.M.,National University of Rio Cuarto | Alberione E.,Instituto Nacional de Tecnologia Agropecuaria | Torres A.,National University of Rio Cuarto | Donat C.,Bio ferm GmbH | And 2 more authors.
Biological Control | Year: 2016

Fusarium head blight (FHB) mainly caused by Fusarium graminearum is a devastating disease that causes extensive yield and quality losses to wheat in humid and semi-humid regions of the world. The biocontrol effect of two bacterial strains on FHB incidence, severity and deoxynivalenol (DON) accumulation in wheat was evaluated in field trials during 2010 and 2011 at Marcos Juarez, Córdoba province, Argentina. Bacillus subtilis RC 218 and Brevibacillus sp. RC 263 applied at anthesis period were evaluated through several combinations of cell type, strains, inoculum density (104 and 106cfu/ml) and physiological modification. A significant and consistent biocontrol effect on FHB severity and DON contamination was observed in all the evaluated treatments during both 2010 and 2011 field trials. Reduction in FHB severity ranged 62-76% and 42-58% for 2010 and 2011 field trials, respectively. When evaluating the effect of the combined strains (104+104 and 106+106cfu/ml), a better biocontrol effect was observed in 2010 field trial. After biocontrol treatments, no DON accumulation was observed in wheat heads; meanwhile in control plots an average of 1372μg/kg DON was detected during the two trials. FHB incidence was significantly reduced by biocontrol treatments during the 2010 field trial but not during the 2011 field trial. The results showed the effectiveness of the two formulated biological control agents in reducing both FHB severity and DON accumulation by F. graminearum under semi controlled field conditions. © 2015 Elsevier Inc.


Boeriu C.G.,Wageningen UR Food and Biobased Research | Frissen A.E.,Wageningen UR Food and Biobased Research | Boer E.,Wageningen UR Plant Research International | Van Kekem K.,Wageningen UR Food and Biobased Research | And 2 more authors.
Journal of Molecular Catalysis B: Enzymatic | Year: 2010

A mild and efficient method for the conversion of C-terminal esters of side-chain protected peptides into an amide function via enzyme-catalysed ammonolysis in organic media with low water content is described. Subtilisin A, the alkaline serine protease from Bacillus licheniformis, was used as biocatalyst and ammonium carbamate as source of ammonia. Response surface methodology (RSM) and central composite design were employed to estimate the effects of reaction parameters such as molar ratio of ammonia source to peptide methyl ester (2:1-10:1), composition of the solvent system (Bu tOH/DMF, % v/v, 70:30-95:5) and water concentration (0.2-0.8%) at different temperatures (30-50 °C) for the preparation of Z-Ala-Phe-NH 2 starting from Z-Ala-Phe-OMe. Optimum reaction conditions for maximum amide yield and minimum secondary hydrolysis were determined from cross-section analysis: temperature 30 °C, solvent composition Bu tOH/DMF 82.5:17.5 (v/v) containing 0.2% water (v/v) and molar ratio of ammonia source to peptide methyl ester of 10:1. The maximum yield of Z-Ala-Phe-NH2 was 87% after 21 h for a quantitative substrate conversion. The method proved to be generally applicable for the synthesis of C-terminal amides of dipeptides with different terminal amino acids and sequence. © 2010 Elsevier B.V. All rights reserved.


Palazzini J.M.,National University of Rio Cuarto | Groenenboom-de Haas B.H.,Wageningen UR Plant Research International | Torres A.M.,National University of Rio Cuarto | Kohl J.,Wageningen UR Plant Research International | Chulze S.N.,National University of Rio Cuarto
Plant Pathology | Year: 2013

The biocontrol effect of Clonostachys rosea (strains 016 and 1457) on Fusarium graminearum, F. avenaceum, F. verticillioides, F. langsethiae, F. poae, F. sporotrichioides, F. culmorum and Microdochium nivale was evaluated on naturally infected wheat stalks exposed to field conditions for 180 days. Experiments were conducted at two locations in Argentina, Marcos Juarez and Río Cuarto. Antagonists were applied as conidial suspensions at two inoculum levels. Pathogens were quantified by TaqMan real-time qPCR. During the first year at Marcos Juarez, biocontrol was observed in one antagonist treatment for F. graminearum after 90 days (73% reduction) but after 180 days, the pathogen decreased to undetectable levels. During the second year, biocontrol was observed in three antagonist treatments for F. graminearum and F. avenaceum (68·3% and 98·9% DNA reduction, respectively, after 90 days). Fusarium verticillioides was not controlled at Marcos Juarez. At Río Cuarto, biocontrol effects were observed in several treatments at different intervals, with a mean DNA reduction of 88·7% for F. graminearum and F. avenaceum, and 100% reduction for F. verticillioides in two treatments after 180 days. Populations of F. avenaceum and F. verticillioides were stable; meanwhile, F. graminearum population levels varied during the first 90 days, and low levels were observed after 180 days. The other pathogens were not detected. The study showed that wheat stalks were important reservoirs for F. avenaceum and F. verticillioides populations but less favourable for F. graminearum survival. Clonostachys rosea (strain 1457) showed potential to reduce the Fusarium spp. on wheat stalks. © 2012 The Authors Plant Pathology © 2012 BSPP.

Loading Wageningen UR Plant Research International collaborators
Loading Wageningen UR Plant Research International collaborators