Simulation of Over-Winter Low-Temperature Responses of Winter Cereals.

The ability to withstand winter stresses determines the geographical distribution and commercial potential of winter cereals. Winter survival is determined by complex, environmentally driven responses that affect just about every measurable morphological, physiological, and biochemical characteristic of the plant.  These responses are not clearly understood making it difficult to design plant breeding and agronomic strategies to optimize production potential, control input costs, and minimize cropping risks. Simulation models offer a valuable means for the integration of information accumulated from detailed physiological, genetic, and genomics studies; thereby improving our understanding of the complicated plant response functions. In addition, a well-designed model provides an effective extension and teaching tool and the opportunity for the systematic investigation of production risks, cause-and-effect processes, and genetic theories. In the 1990’s we developed and deployed a “Winter Cereal Survival Model” based on a series of equations (http://www.wheatworkers.ca/FowlerSite/winter_cereals/WWModel.php) that described acclimation, dehardening, and damage due to low-temperature stress. Recent advances in our understanding of this complex, environmentally induced character have provided us with the opportunity to develop a more robust simulation model with a wider geographic application that now also considers cultivar acclimation threshold induction temperature, respiration stress, photoperiod, and other developmental factors. This presentation will outline the structure and application of the revised winter survival model.