春玉米叶片SPAD值与氮含量及产量的相关性研究

通过田间小区试验,研究不同时期玉米叶片SPAD值与叶绿素、氮含量及产量的相关性,确定SPAD值测定的最佳叶位及时期。结果表明,上位叶SPAD值对氮素的敏感时期顺序为12叶期>10叶期>8叶期;穗位叶SPAD值对氮素的敏感时期顺序为抽雄期>灌浆期>蜡熟期。叶片SPAD值可以很好的反映植株叶绿素和氮含量及产量水平,以某一特定叶片的SPAD值来诊断春玉米氮素营养状况和推荐追肥时期时,10叶期是较为理想的测定时期;作为早期预测玉米产量的指标,12叶期为最佳时期。测定SPAD值方法简便、快捷,不破坏叶片生长,可作为早期预测玉米产量的指标。

Study on the Relationship of SPAD Readings to Nitrogen Content and to Yield in Spring Maize

In the field plot experiments, the relationships of SPAD readings to chlorophyll content, to nitrogen content in maize leaves of different developmental stages and to the yield were studied. The best leaf location and stage of SPAD readings were determined, which could be used to predict the maize production. The results showed that the sensitive periods of the SPAD readings of lobus leaves to nitrogen were stages of 12 leaves, 10 leaves and 8 leaves, respectively. While for the ear leaves, the sensitive periods were stages of tasseling, filling and dough. In addition, the SPAD readings were also suggested to well reflect the chlorophyll content, the total nitrogen content and the maize yield. It was the best stage of 10 leaves in which the leaf SPAD readings could evaluate the nutritional status and recommend the top dressing time. Meanwhile the stage of 12 leaves was the best stage to early predict the maize yield by using the SPAD readings. The methods of measuring the SPAD readings are convenient and not destroying leaf growth, which should be one of the indices to predict maize yield.