Abstract:

To explore the effects of different sowing methods on the photosynthetic characteristics and grain yield of winter wheat, and provide a theoretical basis for further improving winter wheat yield, ‘Jimai 44’ was used as the experimental material and the experiment was conducted at Changyi Experimental Farm of Weifang Academy of Agricultural Sciences and Yueyang Professional Cooperative in Daiyue District of Tai'an City from 2018 to 2019 and 2019 to 2020. Four sowing methods were set up under field conditions including winter wheat precision sowing and semi precision sowing (PS), winter wheat wide precision sowing (WPS), winter wheat seedling with less tillage sowing (LTS), and winter wheat rake pressure integration single grain uniform sowing (SUS). The tillering rate, leaf SPAD value, leaf area index, net photosynthetic rate, effective light intensity radiation, and yield of winter wheat under different sowing methods at the wheat seedling stage, turning green stage, jointing stage, filling stage, and mature stage were measured. The differences in the structure and physiological characteristics of winter wheat population under different sowing methods were analyzed. The experiment showed that the average tillering rate of SUS in two years increased by 14.94%, 29.37%, and 15.03% compared to PS, WPS, and LTS, respectively; the chlorophyll content of flag leaves increased by 7.54%, 7.06%, 5.79%, and 8.30%, 8.15%, 5.50% during flowering and mid filling stages, respectively; the leaf area index increased by 13.8%, 8.88%, and 6.32% during the flowering period, respectively; the net photosynthetic rate of flag leaves increased by 13.15%, 11.50%, and 12.23% during the flowering period, respectively; the photosynthetic effective radiation of the canopy increased by 17.10%, 18.96%, and 10.73% during the flowering period, respectively. In terms of yield, compared to other three sowing methods, SUS increased the number of panicles, thousand grain weight, and yield by 5.17%-8.93%, 5.33%-9.52%, and 6.11%-14.86%, respectively, in two years. Overall, compared to PS, WPS, and LTS, SUS can significantly improve the tillering rate and flag leaf photosynthetic characteristics of wheat, and ultimately achieve an increase in grain yield by increasing the number of spikes and thousand grain weights. The integrated single grain uniform sowing method (SUS) of winter wheat with harrowing and pressing can significantly improve the photosynthetic capacity of winter wheat, increase the effective amount of light radiation intercepted by the canopy, and is a reasonable sowing mode for achieving high yield of winter wheat.

Key words: winter wheat, sowing method, single seed uniform sowing, photosynthetic characteristics, yield