Abstract

To provide base for improving wheat capacity in warmer climate in the North China Plain (NCP), a four-year field experiment was conducted to study temperature effects on length of growth period (LGP), final leaf number (FLN) and yield with six wheat cultivars at 20 test sites (from 32°4´ N to 36°1´ N) of Henan Province in NCP. The results show that the accumulated and average temperature at main stages was significantly different among the four wheat growing seasons (P < 0.01), and LGP, FLN and yield also. In addition, LGP was significantly correlated with accumulated and average temperature at sowing-turning green stage and growth period, and FLN and yield, with the accumulated temperature at almost all stages, but with only theaverage temperature at jointing-blossoming (FLN) or sowing- overwintering stage (yield) and growth period. There was also a positive linear regression relationship between LGP and accumulated temperature at sowing-overwintering stage and growth period between FLN and accumulated and average temperature of growth period, while a negative linear regression relationship between LGP and average temperature of growing period was observed. There was a quadratic regressionrelationship between yield and accumulated and average temperature at sowing-overwintering stage and growth period. In general, with temperature increase, FLN was increased, although LGP decreased. Therefore, if farmers give full consideration to sowing dates and field management when planting, the wheat yield will not suffer too much influence of the global warming in NCP in the future.

Key words: Temperature, wheat, length of growth period (LGP), final leaf number (FLN), yield.