Modelling sheath blight epidemics on rice tillers uri icon

abstract

  • The structure of a model for vice sheath blight which integrates processes at the tiller level and their contribution to epidemics is reported. The model considers two processes, primary and secondary infection, leading to disease increase. It incorporates disease aggregation in terms of accessibility of healthy tillers to infection by the pathogen from diseased tillers, Parameters from the model were derived either empirically ol by numerical optimisation front published data, and from a field experiment. A separate field experiment was conducted for model evaluation, The model has the potential to adequately account for actual epidemics, Sensitivity analysis showed that the intrinsic rate of secondary infection had a large effect on simulated epidemics, while effect of the intrinsic rate of primary infection was comparatively small. The aggregation parameter had a strong effect on simulated epidemics in their later stages. The model adequately, simulated the pattern of actual epidemiological data, except in the later stage of epidemics, when it failed to account for decrease in disease incidence at the tiller level. The model was considered to comply with the requirements of a preliminary simulation model, and approaches to improve its performances are discussed. (C) 1997 Published by Elsevier Science Ltd.

publication date

  • 1997
  • 1997
  • 1997