Effects of Sowing Date and Planting Density on Tillering Dynamics and Yield of Winter Wheat Cultivar Yumai 49

The effects of sowing date and planting density of winter wheat cultivar Yumai 49 on tillering dynamics,spike number and yield were conducted by split plot experiment to figure out the appropriate sowing date and planting density.Results: 1) Tiller number per plant was mainly affected by sowing date and planting density.the tiller number per plant decreased with the postponing of sowing date,and increased with the increasing of planting density,the tillering number kept at a low level no matter when sowed,and the group tillering number reached the highest if sowed at October 9 with the planting density of 1.95 million plants per hectare;2) The sowing date and planting density had significant effects on grain yield.There were significant difference between sowing dates of October 9(the highest,7 991.53 kg/hm2) and October 16(6 631.33 kg/hm2);Significant difference also between planting densities of 1.95 million plants per hectare(the highest,7904.25 kg/hm2) and 1.20 million plants per hectare(the lowest,6 925.32 kg/hm2).Conclusion: The appropriate sowing date and planting density were October 9-16 and 1.95-2.70 million basic seedlings per hectare.