Abstract
A population of 50% transgenic hybrids between seabeet and a transgenic glyphosate tolerant sugarbeet was tested against pure lines of sugarbeet and seabeet to determine if a model could detect any significant differences between the hybrids and the pure lines. The competitive abilities were fairly constant over time. The 95% confidence limits, determined by the “bootstrap”; method, showed that biomass per plant at low densities and maximum biomass production per unit area were not significantly different among the three Beta lines. Based on above‐ground biomass recordings, the hybrid and sugarbeet lines were more competitive than the seabeet line. The hybrid line showed the highest competitive ability, which can be explained by hybrid vigour.