不同株型玉米品种密度制约对源库形成与产量的影响

以紧凑型玉米品种大丰26和平展型太单23为材料,大田条件下设置1.5万,4.5万,7.5万,10.5万株/hm2共4种群体规模,系统研究了不同株型的光合系统与干物质生产、籽粒形成、产量及其构成因素、源库关系等在群体调节上的异同,并提出挖掘不同株型玉米品种产量潜力途径。结果表明,紧凑型大丰26最适密度为7.5万株/hm2,平展型太单23最适密度为4.5万株/hm2,前者产量及构成因素的群体调节作用小于后者,但获得最高经济产量适宜经济系数都在0.5左右,适宜源库比均为1.50左右;生长发育后期,紧凑型大丰26净同化率和干物质积累优势明显;产量构成因素的主次作用因株型而异,平展型太单23在充足穗数前提下,主攻粒质量为主,稳定粒数为辅,而紧凑型大丰26在充足穗数前提下,为充分挖掘生产潜力,宜二者兼顾。

Influence of the Density Control for Different Plant Type Corn Varieties to the Formation of Source-sink and Yield

The experiment were conducted under field conditions with two corn varieties: compact type of cultivar Dafeng 26 and horizontal type of cultivar Taidan 23 planted at 4 densities of 15 000,45 000,75 000 and 105 000 plants/hm2.Photosynthesis system and dry matter,grain growth,yield and its components,source-sink relations were measured and compared between two different plant types in respect of population regulations.Approaches were further proposed to utilize yield potentialities of different plant types of corn.Optimum density for maximal grain yield was 75 000 plants/hm2 for Dafeng 26 and 45 000 plant/hm2 for Taidan 23 respectively.Both plant types performed best at favorite harvest index of 0.5 and favorite source-sink ratio of 1.50.The compact type cultivar exhibited higher NAR and dry matter production than the horizontal type cultivar during late growth phase.Provided with adequate ear number per mu,approaches to higher yield are to increase grain weight firstly and grain number per ear secondly for corn of horizontal type,and to give attention to two items at the same time for compact type.