Abstract:

In order to clarify the effects of sowing dates on the growth and yield of winter wheat with different spike types, the large-spike cultivar ‘Tainong 18’, the medium-spike cultivar ‘Shannong 18’, and the multi-spike cultivar ‘Hongdi 95’ were used as experimental materials，September 30th, October 10th, October 20th and October 30th were set as sowing dates, the wheat plant height, leaf area index, spike number, yield and yield components were measured under different sowing dates. The results showed that with the delay of sowing date, the plant height of ‘Tainong 18’, ‘Shannong 18’, and ‘Hongdi 95’ showed a decreasing trend, while the leaf area index, the number of stem and tiller per unit area, spike number, grains per spike, thousand grain weight, and yield all showed an initial increase and then a decrease trend. The highest yield achieved at 9.38 t/hm², 8.94 t/hm², and 9.22 t/hm² when the sowing date was October 10th, the lowest yield achieved at 7.26 t/hm², 7.32 t/hm², and 7.74 t/hm² when the sowing date was October 30th. Compared to the highest yield, the lowest yield was decreased by 22.6%, 18.1%, and 16.1%. The path analysis of the yield and three yield components showed that the grains per spike of the large-spike cultivar ‘Tainong 18’, the thousand grain weight of the medium-spike cultivar ‘Shannong 18’, and the spike number of the multi-spike cultivar ‘Hongdi 95’ were affected by sowing date. Based on the above results, it could be concluded that the optimal sowing date for all three cultivars was October 10th, and late sowing could cause a decrease in plant height, leaf area index, the number of stem and tiller, and resulted in a decrease of yield.

Key words: winter wheat, sowing date, spike types, plant height, population characteristics, grain yield, path analysis