乙矮合剂对不同密度夏玉米茎秆抗倒伏能力及产量的影响

Effects of Ethylene-Chlormequat-Potassium on Stem Lodging-Resistance and Yield of Summer Maize under Different Sowing Densities

以中单909和浚单20为试验材料,研究乙矮合剂对不同密度夏玉米茎秆形态建成、抗折力、抗倒伏指数及产量的影响。结果表明,随密度增加,株高、穗位高、重心高度、节间长度、倒伏率呈升高趋势,而节间粗度、单位长度节间干重、抗折力及抗倒伏指数呈降低趋势,这些变化品种间存在差异。乙矮合剂处理显著降低株高、穗位高、重心高度,缩短节间长度、增加节间直径和单位长度节间干重,抗折力和抗倒伏指数提高,倒伏率降低;较高密度下（≥7.5万株/hm2）,中单909和浚单20较各自对照增产幅度分别为3.77%∽8.15%和6.73%-68.94%。综上所述,采用合理的种植密度并结合喷施乙矮合剂,能够提高抗倒伏能力和产量,可作为华北夏玉米区高产栽培的重要技术措施。

Using two cuhivars of Zhongdan 909 and Xundan 20 as materials,we investigated the effects of spraying Ethylene-Chlormequat-Potassium（ECK） on the basal stem morphological characteristics, breaking-resistance, lodging resistant index and grain yield for summer maize under different sowing densities. The results showed the increase of sowing density significantly improved the plant height, ear height, gravity center height, length of basal internodes and lodging while decreased stem diameter,dry weight of unit length of internodes, breaking-resistance and lodging resistant index. ECK treatment signifciantly decreased the plant height, ear height and gravity center height, markedly shorten the length of internodes, increased the diameter, dry weight of unit length of internodes, breaking-resistance and lodging resistant index, and thus decreased the lodging. Under the density of ≥7.5 × 104plants/hm2,Zhongdan 909 increased grain yield by 3.77%∽ 8.15% while Xundan 20 improved grain yield by 6.73% -68.94% compared with the control treatment. Therefore, an combination of appropriate sowing den- sity togather with ECK would improve the lodging-resistance and grain yield significantly for summer maize and could be an important agronomical strategy in Northern China for high-yielding maize production.