Temperature By Photoperiod Interactions in Modeling of Soybean Phenology.

This review examined (1) experimental evidences on the roles of temperature and photoperiod on soybean development, especially reproductive stages, and (2) corresponding modeling approaches. Qualitative response to temperature and photoperiod on soybean reproductive stages is well understood, but their quantitative description requires improvement. There are still inconsistent reports or incomplete data on the role of photoperiod on soybean reproductive stages, esp after the first flowering. When models that are developed under a given range of maturity group or planting dates, their performance outside the range are often less satisfactory. This suggests that the nature of photoperiod or their cardinal values need redefined or adjusted under those condition. Although model calibration has often been used as a remedy to this model deficiency, better model functions or parameters estimation mechanisms are needed.