Empirical modeling the response of winter wheat to freezing injury: a combination of variety variances, crop management differences and environmental divergence

BACKGROUND: With the increasing complexity of winter temperature fluctuations and the adoption of new wheat varieties, accurately simulating low-temperature freezing damage in winter wheat has become a critical challenge because existing crop models exhibit significant limitations. The present study developed new simulation algorithms that incorporate the effects of variety, solar radiation, main stem leaf-age and low temperature intensity. Key innovations included dividing the cold hardening process into two distinct stages and introducing a light influence factor and a main stem leaf-age factor to dynamically quantify their impacts on freezing tolerance. RESULTS: Sufficient light during the first stage of cold hardening was found to promote an increase of 4.2 °C in the critical freezing tolerance temperature (CFTT) of winter wheat. Furthermore, a 20-day delay in the sowing period led to a decrease of 1.6 °C in the CFTT. The model effectively simulated CFTT variation under different growth environments and for varieties with different vernalization characteristics, achieving a root mean square error of 0.54 °C during the overwintering period. Although the model performed well in simulating freezing tiller death rates for winter varieties under different low-temperature levels and freezing days, the simulated values for weak winter varieties were slightly lower than the observed values. CONCLUSION: The newly developed model significantly improves the dynamic simulation of freezing tolerance in winter wheat by integrating key physiological and environmental factors. It provides a reliable tool for assessing freezing risks under diverse sowing dates and variety traits, although further refinement is required to enhance accuracy for weak winter varieties. © 2026 Society of Chemical Industry.