ABSTRACT Themaboek PPO 303 uitgegeven naar aanleiding van de studiedag met gelijknamige titel op ... more ABSTRACT Themaboek PPO 303 uitgegeven naar aanleiding van de studiedag met gelijknamige titel op 14 maart 2002 in het WICC te Wageningen, georganiseerd door Praktijkonderzoek Plant & Omgeving en Plant Research International onder auspiciën van het Innovatiecentrum Biologische Landbouw
This article describes a Delphi-based expert judgment study aimed at the selection of indicators ... more This article describes a Delphi-based expert judgment study aimed at the selection of indicators to identify the occurrence of emerging mycotoxin hazards related to Fusarium spp. in wheat supply chains. A panel of 29 experts from 12 European countries followed a holistic approach to evaluate the most important indicators for different chain stages (growth, transport and storage, and processing) and their relative importance. After three e-mailing rounds, the experts reached consensus on the most important indicators for each of the three stages: wheat growth, transport and storage, and processing. For wheat growth, these indicators include: relative humidity/rainfall, crop rotation, temperature, tillage practice, water activity of the kernels, and crop variety/cultivar. For the transport and storage stage, they include water activity in the kernels, relative humidity, ventilation, temperature, storage capacity, and logistics. For wheat processing, indicators include quality data, fraction of the cereal used, water activity in the kernels, quality management and traceability systems, and carryover of contamination. The indicators selected in this study can be used in an identification system for the occurrence of emerging mycotoxin hazards in wheat supply chains. Such a system can be used by risk managers within governmental (related) organizations and/or the food and feed industry in order to react proactively to the occurrence of these emerging mycotoxins.
ABSTRACT The item has text in English with foreword, introduction, vita and summary in Dutch. Vit... more ABSTRACT The item has text in English with foreword, introduction, vita and summary in Dutch. Vita. Thesis (Ph. D.)--Landbouwhogeschool te Wageningen, 1982. Includes bibliographical references.
By screening (Z)-11-tetradecenal and (E)-11-tetradecenal alone, mixed with each other or mixed wi... more By screening (Z)-11-tetradecenal and (E)-11-tetradecenal alone, mixed with each other or mixed with corresponding alcohols or acetates, sex attractants were discovered or improved for nine Lepidoptera. Attractants were found forAcleris sparsana, A. tripunctana, Aphelia viburnana (all Tortricidae),Cilix glaucata (Drepanidae), andCosmia trapezina (Noctuidae). The significance of Δ11-tetradecenals in tortricid sex attractants is discussed.
Most of the known sex attractants and pheromones found for Tortricidae attract species of the sub... more Most of the known sex attractants and pheromones found for Tortricidae attract species of the subfamily Tortricinae. In order to find more sex attractants for species of the subfamily Olethreutinae, about 60 one- and two-component lures were screened for attractancy in different biotopes in the Netherlands. Most of the chemicals tested were straight-chain dodecen-1-ols and their acetates. The species captured belonged to the following families and subfamilies: Tortricinae (5), Olethreutinae (30), Noctuidae (2), Gelechiidae (1), Gracillariidae (1). Some of the species captured are recorded as pest species in forestry:Epinotia tedella, Gypsonoma aceriana, Cydia strobilella, C. zebeana, Petrova resinella, Blastesthia turionella, andB. posticana.
ABSTRACT : Habitat quality affects the condition of predatory beetles in terms of size and weight... more ABSTRACT : Habitat quality affects the condition of predatory beetles in terms of size and weight. Carabid body weight and size are defined and measured in many ways. The way of collecting and preserving of beetles affects these parameters. This makes comparison between studies difficult. This paper presents more precise methods to determine the condition of the carabid P. cupreus in farmland. Beetles were caught alive by using pitfall traps and were weighted. Elytra maximum length and area were measured by image analysis. The elytra area appeared to be a good indicator for beetle size. The relative fresh weight was defined as the fresh weight/elytra area. To convert weight from formalin trapped beetles into fresh or dry weight, relationships between different weighing procedures were established. Analyses were made of the relation between various weight and size parameters. The relative fresh weight of both sexes increases significantly early in the season. Weight and relative fresh weight do not differ significantly between sexes. Since females are expected to respond more clearly to environmental circumstances in terms of weight, variability should be higher. This is best reflected in the relative fresh weight which is much more variable in females than in males. Therefore this parameter is most suitable for assessing individual conditions. For P. cupreus the multiplication factor to transform alcohol weight into fresh weight is 1.19. Because all dry, fresh and alcohol weights are highly correlated it depends on the research questions and circumstances which method to choose.
... Page 2. 254 C. /. H. Booij, S. Voerman and LPM Willemse idana (L.) (ARN et al. ... Usually 1 ... more ... Page 2. 254 C. /. H. Booij, S. Voerman and LPM Willemse idana (L.) (ARN et al. ... Usually 1 mg of each compound or blend of compounds to be tested was a plied to a red-rubber sleeve stopper, 5 mm x 9 mm (Arthur H. Thomas Company, Philadelp!ia, PA. 19105, USA, Cat. No. ...
Intercropping is used to reduce pests and diseases by decreasing their establishment or performan... more Intercropping is used to reduce pests and diseases by decreasing their establishment or performance on the crop, and by enhancing antagonist activity. The effect of intercropping cabbage with white and subterranean clover on epigeic predator activity-density was studied in two successive years in the Netherlands. The presence of clover as an intercrop resulted in significantly higher predator activity-densities and diversity,
ABSTRACT Themaboek PPO 303 uitgegeven naar aanleiding van de studiedag met gelijknamige titel op ... more ABSTRACT Themaboek PPO 303 uitgegeven naar aanleiding van de studiedag met gelijknamige titel op 14 maart 2002 in het WICC te Wageningen, georganiseerd door Praktijkonderzoek Plant & Omgeving en Plant Research International onder auspiciën van het Innovatiecentrum Biologische Landbouw
This article describes a Delphi-based expert judgment study aimed at the selection of indicators ... more This article describes a Delphi-based expert judgment study aimed at the selection of indicators to identify the occurrence of emerging mycotoxin hazards related to Fusarium spp. in wheat supply chains. A panel of 29 experts from 12 European countries followed a holistic approach to evaluate the most important indicators for different chain stages (growth, transport and storage, and processing) and their relative importance. After three e-mailing rounds, the experts reached consensus on the most important indicators for each of the three stages: wheat growth, transport and storage, and processing. For wheat growth, these indicators include: relative humidity/rainfall, crop rotation, temperature, tillage practice, water activity of the kernels, and crop variety/cultivar. For the transport and storage stage, they include water activity in the kernels, relative humidity, ventilation, temperature, storage capacity, and logistics. For wheat processing, indicators include quality data, fraction of the cereal used, water activity in the kernels, quality management and traceability systems, and carryover of contamination. The indicators selected in this study can be used in an identification system for the occurrence of emerging mycotoxin hazards in wheat supply chains. Such a system can be used by risk managers within governmental (related) organizations and/or the food and feed industry in order to react proactively to the occurrence of these emerging mycotoxins.
ABSTRACT The item has text in English with foreword, introduction, vita and summary in Dutch. Vit... more ABSTRACT The item has text in English with foreword, introduction, vita and summary in Dutch. Vita. Thesis (Ph. D.)--Landbouwhogeschool te Wageningen, 1982. Includes bibliographical references.
By screening (Z)-11-tetradecenal and (E)-11-tetradecenal alone, mixed with each other or mixed wi... more By screening (Z)-11-tetradecenal and (E)-11-tetradecenal alone, mixed with each other or mixed with corresponding alcohols or acetates, sex attractants were discovered or improved for nine Lepidoptera. Attractants were found forAcleris sparsana, A. tripunctana, Aphelia viburnana (all Tortricidae),Cilix glaucata (Drepanidae), andCosmia trapezina (Noctuidae). The significance of Δ11-tetradecenals in tortricid sex attractants is discussed.
Most of the known sex attractants and pheromones found for Tortricidae attract species of the sub... more Most of the known sex attractants and pheromones found for Tortricidae attract species of the subfamily Tortricinae. In order to find more sex attractants for species of the subfamily Olethreutinae, about 60 one- and two-component lures were screened for attractancy in different biotopes in the Netherlands. Most of the chemicals tested were straight-chain dodecen-1-ols and their acetates. The species captured belonged to the following families and subfamilies: Tortricinae (5), Olethreutinae (30), Noctuidae (2), Gelechiidae (1), Gracillariidae (1). Some of the species captured are recorded as pest species in forestry:Epinotia tedella, Gypsonoma aceriana, Cydia strobilella, C. zebeana, Petrova resinella, Blastesthia turionella, andB. posticana.
ABSTRACT : Habitat quality affects the condition of predatory beetles in terms of size and weight... more ABSTRACT : Habitat quality affects the condition of predatory beetles in terms of size and weight. Carabid body weight and size are defined and measured in many ways. The way of collecting and preserving of beetles affects these parameters. This makes comparison between studies difficult. This paper presents more precise methods to determine the condition of the carabid P. cupreus in farmland. Beetles were caught alive by using pitfall traps and were weighted. Elytra maximum length and area were measured by image analysis. The elytra area appeared to be a good indicator for beetle size. The relative fresh weight was defined as the fresh weight/elytra area. To convert weight from formalin trapped beetles into fresh or dry weight, relationships between different weighing procedures were established. Analyses were made of the relation between various weight and size parameters. The relative fresh weight of both sexes increases significantly early in the season. Weight and relative fresh weight do not differ significantly between sexes. Since females are expected to respond more clearly to environmental circumstances in terms of weight, variability should be higher. This is best reflected in the relative fresh weight which is much more variable in females than in males. Therefore this parameter is most suitable for assessing individual conditions. For P. cupreus the multiplication factor to transform alcohol weight into fresh weight is 1.19. Because all dry, fresh and alcohol weights are highly correlated it depends on the research questions and circumstances which method to choose.
... Page 2. 254 C. /. H. Booij, S. Voerman and LPM Willemse idana (L.) (ARN et al. ... Usually 1 ... more ... Page 2. 254 C. /. H. Booij, S. Voerman and LPM Willemse idana (L.) (ARN et al. ... Usually 1 mg of each compound or blend of compounds to be tested was a plied to a red-rubber sleeve stopper, 5 mm x 9 mm (Arthur H. Thomas Company, Philadelp!ia, PA. 19105, USA, Cat. No. ...
Intercropping is used to reduce pests and diseases by decreasing their establishment or performan... more Intercropping is used to reduce pests and diseases by decreasing their establishment or performance on the crop, and by enhancing antagonist activity. The effect of intercropping cabbage with white and subterranean clover on epigeic predator activity-density was studied in two successive years in the Netherlands. The presence of clover as an intercrop resulted in significantly higher predator activity-densities and diversity,
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