密度、种植方式对夏玉米茎秆抗倒伏能力的影响

为了提高玉米抗倒特性,在豫北高产灌区生产条件下,以郑单958和浚单20为试验材料,采用了等行距、宽窄行种植方式,设6.75万、7.50万、8.25万、9.00万株/hm24个密度处理,研究了不同密度、种植方式对夏玉米茎秆抗倒伏能力的影响。结果表明:在成熟期,郑单958的平均茎折率比浚单20低43.55%,茎秆第三节间的茎粗系数、茎秆外皮穿刺强度分别比浚单20高0.04、564.1 N/mm2,宽窄行种植的玉米茎粗系数、外皮穿刺强度比等行距种植的高0.01、59.23N/mm2。随着密度的增加,玉米的茎折率、空秆率和穗位系数增大,茎粗系数和穿刺强度降低。郑单958在密度为8.25万株/hm2、采用宽窄行种植时抗倒伏能力最强,而浚单20表现最好的为7.50万株/hm2的宽窄行种植方式。

Effects of Planting Densities and Modes on Stem Lodging Resistance of Summer Maize

In order to improve stem lodging resistance of summer maize,effects of planting densities and modes on stem lodging resistance were studied under the ecological condition of northern Henan province.Two cultivars,Zhengdan 958 and Xundan 20,were used as materials and four densities,6.75×104,7.50×104,8.25×104,9.00×104 plants/ha,were adopted in the experiment with two planting modes,wide-narrow row and the same row.The results showed that the stalk breaking percentage of Zhengdan958 was lower than Xundan 20 by 43.55% at maturity,and stem diameter coefficient of the third internode and stalk crushing strength of Zhengdan 958 were more than Xundan 20 by 0.04,564.1 N/mm2,while these indexes under the planting mode of wide-narrow row were higher than those under the same row by 0.01,59.23 N/mm2.With the increase of density,the stalk breaking percentage,barren stem percentage and ear position coefficient increased,but the stem diameter coefficient and stalk crushing strength decreased.The stem lodging resistance of Zhengdan 958 was the strongest at the density of 8.25×104 plants/ha with wide-narrow-row planting mode.The stem lodging resistance of Xundan 20 was strong at the density of 7.50×104 plants/ha with wide-narrow-row planting mode.