Het mineralenspoor in 'Koeien & Kansen'. Uitgangssituatie mineralenstromen

Dit rapport beschrijft de mineralenhuishouding van 12 bedrijven, verspreid over heel Nederland, in 1997. De 12 bedrijven doen mee met het project ‘Koeien en Kansen’ en zijn via een wervingsadvertentie in landbouwbladen opgespoord. In het voorjaar van 1999 is het project ‘Koeien en Kansen’ van start gegaan. Het project richt zich op het ontwikkelen van een aantal praktijkbedrijven tot duurzame melkveebedrijven en het uitdragen van kennis daarvan. Elk praktijkbedrijf is representatief voor een deel van de Nederlandse melkveehouderij en samen zijn de bedrijven representatief voor de blijvers in de Nederlandse melkveehouderi

An individual-based model of the evolution of pesticide resistance in heterogeneous environments : Control of meligethes aeneus population in oilseed rape crops

Copyright: © 2014 Stratonovitch et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Preventing a pest population from damaging an agricultural crop and, at the same time, preventing the development of pesticide resistance is a major challenge in crop protection. Understanding how farming practices and environmental factors interact with pest characteristics to influence the spread of resistance is a difficult and complex task. It is extremely challenging to investigate such interactions experimentally at realistic spatial and temporal scales. Mathematical modelling and computer simulation have, therefore, been used to analyse resistance evolution and to evaluate potential resistance management tactics. Of the many modelling approaches available, individual-based modelling of a pest population offers most flexibility to include and analyse numerous factors and their interactions. Here, a pollen beetle (Meligethes aeneus) population was modelled as an aggregate of individual insects inhabiting a spatially heterogeneous landscape. The development of the pest and host crop (oilseed rape) was driven by climatic variables. The agricultural land of the landscape was managed by farmers applying a specific rotation and crop protection strategy. The evolution of a single resistance allele to the pyrethroid lambda cyhalothrin was analysed for different combinations of crop management practices and for a recessive, intermediate and dominant resistance allele. While the spread of a recessive resistance allele was severely constrained, intermediate or dominant resistance alleles showed a similar response to the management regime imposed. Calendar treatments applied irrespective of pest density accelerated the development of resistance compared to ones applied in response to prescribed pest density thresholds. A greater proportion of springs own oilseed rape was also found to increase the speed of resistance as it increased the period of insecticide exposure. Our study demonstrates the flexibility and power of an individual-based model to simulate how farming practices affect pest population dynamics, and the consequent impact of different control strategies on the risk and speed of resistance development.Peer reviewe