Effect of Sowing Date and Planting Density on Population Quality,Chlorophyll Fluorescence and Yield of Wanmai 52 in Huaibei Area

In order to explore the suitable sowing date and density in main wheat production area of Huaibei,the effects of six sowing dates of S1(October 3),S2(October 10),S3(October 17),S4(October 24),S5(October 31),S6(November 7)and four planting densities of D1(120×104 plants·hm-2),D2(210×104 plants·hm-2),D3(300×104 plants·hm-2),D4(390×104 plants·hm-2)on physiological characteristics and yield of Wanmai 52(semi-winter)was studied.The results indicated that the highest dry matter weight of wheat population was the combination of S2D4 and S3D4 at heading stage,and of S2D3 and S3D3 at maturity.The leaf area index of wheat at filling stage increased with the increasing of planting density,and the highest values were observed at the sowing dates of S2 and S3.Under the same planting density,the highest values of chlorophyll content at each growth stage and each chlorophyll fluorescence parameter(Fo,Fm,Fv/Fm,ETR andΦPSII)at fillingstage of wheat were all appeared at the sowing dates of S2 and S3,while they were all decreased with the increasing of planting density under the same sowing date.The highest yield of Wanmai 52 was observed in the combination of S2D2,S2D3,S3D2 and S3D3,and was 7 790.5,8 122.4,7 826.4and8 261.1kg·hm-2,respectively.This study suggested that the suitable sowing date of Wanmai52in main wheat production area of Huaibei was October 10~October 17,and the suitable planting density was the basic seedling 210×104~300×104 plants·hm-2,the recommended combinations of sowing date and density of the similar wheat varieties were S2D2,S2D3,S3D2and S3D3.