Development and validation of a model describing the curd induction of winter cauliflower

A simulation model was proposed to predict changes in apex development duri ng the curd induction phase of winter cauliflower (Brassica oleracea var. b otrytis L.). The model included a continuous asymmetric function for temper ature based on a gamma distribution using only two parameters. The model wa s fitted to data for the two winter cauliflower selections `March' and `Dec ember/January'. The temperature function implied little apex expansion belo w 4 and 8 degreesC for `March' and `December/January' respectively but the upper limit of 17 degreesC was the same for both selections. The modal valu e of 9.4 degreesC for `March' was lower than that for `December/January' at 11.7 degreesC. The model accurately predicted progress through curd induct ion on independent data sets for each selection.