To systematically collate and synthesise published and unpublished evidence in order to evaluate the effectiveness of herbicides used for the control of ragwort (Senecio) species, by the use of datasets concerning measures of mortality rates and/or population density, following herbicide application.
The secondary objective was to explore, when possible, the following reasons for heterogeneity among the datasets:
- Species of ragwort
- Dosage of the herbicide
- Month of treatment
- Time period between treatment and recording of results.