种植密度与化学调控对春玉米茎秆性状及抗倒伏能力的影响

Effects of Planting Density and Chemical Regulation on Stem Traits of Spring Maize

以迪卡159为供试材料,设置6.0×10^(4)(D1)、7.0×10^(4)(D2)、8.0×10^(4)(D3)和9.0×10^(4)株/hm^(2)(D4)4个密度水平,在8展叶期喷施化控剂玉多十(HK)和清水为对照(CK)2个处理,研究不同种植密度与化学调控技术对植株茎秆性状的影响。结果表明,随种植密度的增大,迪卡159的株高、穗位高显著增高,茎秆节间长变长,茎粗变小,扁率增大,茎秆强度变弱。HK处理后,株高、穗位高显著降低,4~5节位节间长大幅度减少,茎粗增加,扁率降低,茎秆强度增强,茎秆横折强度与穿刺强度在3个时期均随种植密度的上升呈现整体下降趋势,并于乳熟期达到最大值。HK处理后,茎秆的横折强度与穿刺强度增强,其中,4~5节位提升幅度最大。HK处理增加了灌浆期与乳熟期第3节位的木质素与纤维素含量,D1、D2、D4密度下效果显著。倒伏率随种植密度的升高呈上升趋势;HK处理可以显著降低倒伏率,4个密度下分别比对照降低了26.15%、47.72%、35.17%和33.82%。

Dika 159 was used as experimental materials.Four density levels of 6.0×10^(4) plants/ha(D1),7.0×10^(4) plants/ha(D2),8.0×10^(4) plants/ha(D3)and 9.0×10^(4) plants/ha(D4)were set.At 7-8 leaf development stage,experimental treatments sprayed chemical YuDuoShi(HK)and control group only sprayed water(CK).The results showed that with the increase of planting density,the plant height and ear height of Dika 159 increased significantly,the internode length became longer,the stem diameter became smaller,the flattening rate increased,and the stem strength became weaker.In HK treatments,plant height and ear height decreased significantly,internode Growth at 4-5 nodes decreased,stem diameter increased,flattening rate decreased,and stem strength increased.Stem transverse crushing strength and puncture strength showed an overall downward trend with the increase of planting density at three stages,and reached the maximum value at milk stage.In HK treatments,the transverse crushing strength and puncture strength of the stem were enhanced,and the increase range of 4-5 node was the largest;HK treatment increased the lignin and cellulose content of the third node at the filling stage and milk stage,and the effect was significant at D1,D2 and D4.HK treatment could significantly reduce the lodging rate,which decreased by 26.15%,47.72%,35.17%and 33.82%respectively compared with the control.