Modelling the potential for gene escape in oilseed rape via the soil seedbank: its relevance for genetically modified cultivars

A simple mechanistic model is presented which describes population dynamics of volunteer oilseed rape within a field. The model calculates the number of volunteers appearing in each crop and the seedbank after each crop. The main input variables are harvesting losses when the crop is oilseed rape, c rop rotation, soil cultivation, moisture distribution in soil and the level of volunteer control in each crop in the rotation. The impact of the amoun t of harvesting losses and of the level of volunteer control are tested and presented in this paper. Simulations of the effects of replacing oilseed r ape with linseed are shown. Sensitivity analysis revealed that the relation ship between the number of volunteer seedlings and the size of the seedbank in the absence of direct control measures was of particular importance and further research is necessary to improve the definition of this relationsh ip.