Influence of the sowing period and denesityon yield and yield components of three semi -winter wheat varieties

Abstract

Three semi-winter wheat varieties Zhoumai 18, Zhoumai 22 and Bainong 207 were selected as materials for this study to study quality seeds and reliable methods capable of supporting the dominant wheat cultivation technology in southern Huanghuai. In our experiments, each variety was used in six sowing times and seven planting densities. The results showed that: (1) varieties had significant effects on yield and yield components. The yield among different varieties in the order of high and low was Bainong 207 >Zhoumai 22 >Zhoumai 18; suitable sowing date from October 1 to October 22, and the density is 300 ~ 525 × 104 plant·hm-2. (2) The interaction of the date and planting density affects the yield and its constituent factors.The best combination of sowing date and density for Zhoumai 18 and Bainong 207 were 450×104 plant·hm-2 on October 8, and the yields were 10829.0 kg·hm-2 and 11891.7 kg·hm-2, respectively, and Zhoumai 22 is 450 × 104 plant·hm-2 on October 15 and the yield is 10792.5kg·hm-2. It can be seen that the best sowing date is October 8~15, and the seeding density is 450 × 104 plant·hm-2. All three varieties showed that the spikes was higher during the high-density and the suitable sowing date treatment (October 8~15, 525~675 × 104 plant·hm-2), and the grain number per spike was higher when the density was suitable (300-525 ×104 plant·hm-2), the thousand-grain weight is higher in the low-density treatment (225~300 × 104 plant·hm-2). (3) There are significant differences in the percentage of tiller among different varieties. The order of the three varieties is Bainong 207 >Zhoumai 18 >Zhoumai 22. With the postponement of the sowing date and the increase of the sowing density, the population tiller number (PTN) increased, and the percentage of earring-tiller gradually decreased. In summary, the appropriate sowing date and density can make the yield and its constituent factors make full use of light energy and water which build a reasonable population structure, and increase yield.