Effects Of Planting Density On Growth Characters, Yield And Quality Of Winter Wheat Cultivars Of Big Spike In Dryland

The winter wheat is one of the most important crops in northwest arid area.In order to verify the production adaptability and potentiality of winter wheat of big spike in dryland with higher fertility,and choose the best combination of cultivar and density when not only the maximum yield ,but also the most superiority quality is gained, this experiment was studied.Jinmai 47 (CK) ,the middle spike cultivar, and three cultivars of big spike are selected as trail materials, under the condition of dryland and higher fertilizer level, the effects of planting density on agronomic characters,yield and yield components and quality of winter wheat of big spike are studied systematically, and the theorial base and technical supporting on breeding innovations and the cultivation system of higer yield and superiorer quality of big spike in dryland will be provided.The main results were showed as follows:1. In the jointing stage, with the increasing planting density,the seedling height increases ,while the sum tillering number , big tillering numbers ,secondary root number , fresh weight and dry weight of single-plant decreases, and the differences between planting densities and cultivars are significant.2.From boot stage to milk stage,the leaf area indexes of the upper three leaves of all cultivars are highest in boot stage,and decrease after this stage. From boot stage to middle milk stage, the leaf area indexes of the upper three leaves of all cultivars increase with the increasing planting density ,and after the middle milk stage,the trend is increase, followed by decrease .3.The basic angle,open angle and drooping angle of the upper three leaves of all cultivars decrease with the increasing planting density ,and the differences between planting densities are significant; the law on the basic angle,open angle and drooping angle of the upper three leaves of all cultivars is found:the angle of flag leaf is smaller than second leaf from top and third leaf from top,the angle difference of leaf decreases gradually from bottom to top.The leaf areas of the upper three leaves of all cultivars decrease with the increasing planting density ; the leaf area of the second leaf is the biggest,and followed by the third leaf and flag leaf. The plant shape of three cultivars of big spike is more terser than that of Jinmai 47,and at the same time,the leaf area of the upper three leaves is bigger than that of Jinmai 47.4.The Pn,Co,Tr of flag leaf of all cultivars increases firstly,and decreases following with the increasing planting density ;the effects of density on Ci is fairly slight; and the differences between planting densities are insignificant except Jinmai 47 ;WUE decreases with the increasing planting density.5. With the increasing planting density, the plant height, the final spike number and ineffective small spike number increase,and the differences between planting densities are significant; at the same time, the spike length,the effective small spike number, the grain number per spike and thousand grain weight decreases ; the yield trend of all the cultivars is increase, followed by decrease, and the maximum yield is gained when density is 315×104/hm2, and the difference of yield between 315×104/hm2 and 420×104/hm2 is insignificant.The regression analysis shows that, the final spike number and density are interrelated tightly in plus direction;on the contrary, the grain number per spike and thousand grain weight and density are interrelated tightly in negative direction;while the relation between the yield and density is parabola.6. With the increasing planting density,the protein content,hardness of all cultivars increases firstly,and decreases in the following,and the maximum is gained when density is 420×104/hm~2, and the difference of densities are insignicant.When it comes to the Sedi mentation, the Sedi mentation of Jinmai 47 increases,while that of three cultivars of big spike increases firstly,and decreases in the following ,and the maximum is gained when density is 315×104/hm~2;the effects of density on water content and loaf volume is fairly slight.In a word,except Sedi mentation, the effects of density on the other quality indexes are fairly slight.