Stress Stability

wheat field


In order to identify varieties that perform well in both good conditions and under stress, we conduct side-by-side trials at a subset of our statewide trial locations. In these trials common wheat and triticale varieties are grown under fully watered and fertilized conditions and under conditions of terminal drought or nitrogen stress. These trials help to identify varieties that perform well under a wide range of management conditions, and help us understand why certain varieties perform better or worse in certain years and locations.

Heat map represents the average stress stability of common hard spring wheat varieties to terminal drought and nitrogen (N) stress in trials conducted in Yolo and Fresno Counties of California during the 2018-19, 2019-20, and 2020-21 seasons. Stability is measured as the relative performance of an individual variety in the unstressed conditions plus or minus its relative performance in the stress conditions at the same location (for more info see illustration at the bottom of the page). Terminal drought and N stress responses are based on averages of three site-years of data. Stress trials are managed identically except for the exclusion of irrigation after the vegetative growth period (terminal drought) or the exclusion of N fertilizer additions throughout the season (N stress).

average stress summaries


2018-19 – 2020-21 Summary

  • Common Wheat and Triticale Combined

2017-18 – 2019-20 Summary

  • Common Wheat and Triticale Combined

2016-17 – 2017-18 Summary

How are these results calculated?