不同行距配比对玉米光合生理指标及茎秆特性的影响

Effect of Row Spacing Rate on Stem Mechanic Property and Photosynthetic Physiological Indexes of Maize

以‘大丰30’为试验材料,在同一密度下(75000株/hm^2)设置5种不同行距配比,研究不同行距配比对玉米光合生理指标及茎秆力学特性的影响。结果表明:行距配比为40 cm×80 cm时,棒三叶的叶绿素含量(SPAD)在灌浆期达到峰值;行距配比为30 cm×90 cm时,棒三叶净光合速率在灌浆期最高。大口期开始,行距配比为40 cm×80 cm时,叶面积指数(LAI)最高。单株干物质积累量以40 cm×80 cm最高。各行距配比的茎秆硬皮穿刺强度与茎秆弯曲性能随着节位的下降均呈逐渐增强的趋势,从大到小为40 cm×80 cm>50 cm×70 cm>30 cm×90 cm>60 cm×60 cm>20 cm×100 cm。穗长、穗粗、千粒重和穗粒数各处理间均有不同变化,行距配比为40 cm×80 cm时产量最高,比等行距60 cm×60 cm增产7.96%。由此可见,行距配比为40 cm×80 cm,有利于大穗型品种‘大丰30’的光合性能和茎秆强度的提高,从而达到抗倒伏增产的目的。

Effects of five different row spacing on stem mechanic property and photosynthetic physiological indexes of maize were studied under the same density(75000 plants/hm^2),and’Dafeng 30’was used as the experimental material.The results showed that the chlorophyll content of three-ear-leaves was the highest at the grain-filling stage when the rate of row spacing was 40 cm×80 cm;the net photosynthesis of three-earleaves was the highest at the grain-filling stage when the rate of row spacing was 30 cm×90 cm;the leaf area index(LAI)was the highest from flare opening when the rate of row spacing was 40 cm×80 cm.The single trunk dry matter accumulation was the highest at the rate of row spacing 40 cm×80 cm.It was found that the stalk hard rind penetration strength and stem bending capacity were enhanced with the descend of internodes,in an order from high to low as:40 cm×80 cm>50 cm×70 cm>30 cm×90 cm>60 cm×60 cm>20 cm×100 cm.Panicle length,ear diameter,number of grains per panicle and 1000-grain weight had different changes among the treatments,the yield was the highest at the row spacing of 40 cm×80 cm,increased by 7.96%compared with that of the equal row spacing 60 cm×60 cm.Taken together,the best rate of row spacing is 40 cm×80 cm,which is more conducive to photosynthetic characteristics and stem strength of’Dafeng 30’,and could achieve the goal of lodging resistance and yield increase.