不同氮水平下化学调控对旱地冬小麦生长及产量的影响

通过田间试验研究了不同氮水平下分阶段采用多效唑及其与6-BA配合对小偃6号和小偃22两小麦品种生长及产量的影响.结果表明,多效唑浸种显著增加了小麦的单株分蘖,拔节初期喷施多效唑明显降低了两品种的株高.不同生长阶段使用生长调节物质均增加了两品种的叶面积和叶片叶绿素SPAD值,尤其以灌浆初期喷施6-BA后对成熟期叶片SPAD值的增加幅度最为突出,表明其具有延缓叶片衰老,延长叶片功能期的效果.采用多效唑及其与6-BA配合进行分阶段化学调控具有明显增产作用,其中多效唑与6-BA相结合处理较清水处理小麦产量提高了601.2 kg/hm2,增产幅度达显著水平;小麦穗粒数和千粒重的增加是其籽粒增产的主要原因.由此可见,在小麦生长的不同阶段采取不同的化控措施,可以有效地调节小麦生长发育,达到提高作物产量的目的.

Effects of plant growth regulators on the growth and yield of winter wheat at different N-application rates on dryland

A field experiment with the split-plot design was conducted to study the effects of the application rates of nitrogen and growth regulator substances on the growth and grain yield of 2 winter wheat varieties.The result showed that seeds soaked with PP333 significantly increased the tiller number per plant at different N-application rates.The height of Xiaoyan 22 and Xiaoyan 6 were obviously decreased by spraying PP333 in jointing stage,and the decreasing rate of Xiaoyan 6(1.73 cm) was more obvious than that of Xiaoyan 22(1.57 cm).The leaf area and leaf SPAD value of the 2 cultivars were also increased by the PGRs during different growth phases;and the increase of leaf SPAD value was significant when the 6-BA was sprayed during the grain filling stage,which indicates the positive role of plant growth regulators(PGRs) in improving the grain filling by delaying the senescence of flag leaf and extending the function time of leaves.In addition,the grain number per plant,1 000-grain weight,and the yield were obviously improved by using PGRs in different growth phase.PP333BA increased wheat yield by 348.6 kg/hm~2 and 601.2 kg/hm~2 compared with PP333 and Water,respectively.