摘要： 以田间大豆为材料，研究了干热天气条件下群体大豆的光合午休及其形成原因，并对喷灌效应进行分析。结果表明，大豆群体光合午休要比单叶光合午休为重，诱发群体光合午休的原因是低湿、高温；喷灌可明显地提高空气相对湿度（RH）,降低空气温度（Ta）,增加群体光合速率（Pc）和累积光合速率，并对产生光合午休的临界湿度和适宜喷灌时间提出了初步见解。

关键词: 大豆, 群体, 光合午休, 喷灌

Abstract: The photosynthetic midday depression (PMD)of soybean (G}ycine max) grown in field at hot summer days is caused by low atmosphere humidity and high air temperature, aad decreased by spray irrigation. PMD of soybean population is more serious than that of a single leaf. Spray irrigation can enhance the population photosynthetic rate and accumulated photosynthetic rate, morever, it can raise relative humidity and lower the temperature, The critical level of dryness causing PMD and suitable time for spray irrigation are discussed.

Key words: Soybean, Population, Photosynthetic midday depression, Spray irrigation

中图分类号: 

• S565.107.1