Modeling leaf appearance rate for Canada Western Red Spring wheat cultivars

The rate of leaf appearance [LAR (d-1)] was observed for two older (Marquis and Neepawa) and two newer (AC Barrie and AC Elsa) Canada Western Red Spring (CWRS) wheat (Triticum aestivum L.) cultivars grown in a semiarid environment on the Canadian prairies for four years. Although the newer cultivars significantly increased yield LAR did not change when compared with the older cultivars. A simulation model developed by Jame et al. (1998a), and using coefficients for Neepawa determined from a previous study adequately predicted LAR for all four cultivars.Key words: Wheat, leaf appearance rate, temperature, daylength, model