Abstract:

To investigate the effects of sowing date on the growth, development, and yield of spring maize in the hilly area of northeast Sichuan, three varieties (‘Zhongyu 3’, ‘Chengdan 30’ and ‘Huayu 130’) were selected as experimental materials. A two-factor split-plot design was adopted in field experiments to analyze the effects of eight sowing dates on the growth process, morphological characteristics, and yield of the three spring maize varieties. The results showed that sowing date significantly regulated maize growth progress. With the delay of sowing date, the duration of each growth stage and the whole growth period shortened gradually, and the stage from seedling emergence to jointing was most obviously affected. Plant height and ear height presented a trend of initial decline, subsequent rise and final drop as sowing date postponed. In terms of varietal difference, both indicators ranked as ‘Chengdan 30’> ‘Zhongyu 3’ >‘Huayu 130’. Maize yield decreased continuously with delayed sowing date. Compared with sowing date A₁ (March 14), the yield of ‘Zhongyu 3’, ‘Chengdan 30’ and ‘Huayu 130’ under sowing date A₈ (May 2) decreased by 18.48%, 18.22% and 17.87% respectively. It indicates that the yields of ‘Sangdian 30’ and ‘Zhongyu No.3’ are more susceptible to the influence of sowing date. Meteorological factors indirectly affected maize morphological formation and yield by regulating sowing time. Accordingly, the optimal sowing window for spring maize in hilly area of northeast Sichuan is the middle and late March. Yield declines sharply when sowing is conducted later than April 18. ‘Huayu 130’ is recommended to maintain stable yield if timely sowing cannot be ensured.

Key words: sowing date, maize, hilly area of northeast Sichuan, plant height, ear height, growth and development, yield