双重化控对夏玉米穗花发育及产量的影响

In response to the serious lodging of summer maize in the Huanghuaihai Plain, and the varying conclusions regarding yield increase or decrease after spraying chemical control agents, this study investigated the effects of different density levels and control promotion combined with dual chemical control techniques on the development of female ear and flower, hormone levels, assimilate content, and yield of maize, and explored the physiological mechanism of dual chemical control affecting female ear development and yield. The results showed that: (1) The dual chemical control and lodging resistance technology significantly inhibited the development of female ears in maize, significantly reduced the number of fertilized flowers and the fertilization rate of small flowers, and reduced the number of grains per ear. (2) The dual chemical control technology significantly reduced the IAA content in female spikes, increased the GA3 and ABA content in female spikes, decreased sucrose content, affected the distribution of photosynthetic products, and ultimately affected maize yield. This indicates that the densification and chemical control technology significantly inhibits the development of female ears in maize, reduces the number of grains per ear, and thus affects maize yield. Therefore, promoting grain setting and increasing the number of grains per spike are the main targets for further improvement of this technology.