Research was conducted to determine the utility of a single, temperature-independent Weibull function for describing cumulative seed germination under several temperature regimes with 14 sets of weed and crop seed germination data. A modified cumulative Weibull function was derived to distribute germination times for individuals within the population and distributed the occurrence of germination given ample sample size and appropriate sample interval. The descriptive and predictive attributes of the stochastic model component are well suited for incorporation into seed germination models and are likely applicable to models to predict distribution of times for other developmental processes of plants.
