花生冠层温度日变化及其与地表温度和光照度的关系
Relationships between diurnal changes of peanut canopy temperature and surface temperature and illuminance

【目的】探索花生冠层温度日变化特征及其与地表温度和光照度的关系，以揭示不同基因型花生品种冠层温度差异机理。【方法】于花生结荚期和饱果期，分别应用红外测温仪和照度计对花生冠层温度、地表温度日变化和冠层、1/2株高层、0.02 m株高层光照度日变化（06:00－18:00，每隔2 h观测1次）进行了观测。【结果】不同基因型花生品种冠层温度存在明显分异，冠层温度偏高的品种（暖型花生）持续偏高，冠层温度偏低的品种（冷型花生）持续偏低，且越是到生育后期，差异越明显。结荚期和饱果期不同温度型花生冠层温度、地表温度日变化均能用三次多项式很好地拟合，各层光照度日变化均能用二次多项式很好地拟合。冠层温度日变化与地表温度和各层光照度呈显著（P<0.05）或极显著（P<0.01）正相关，但不同生育时期各因子的作用大小不同，结荚期：地表温度>1/2株高层光照度>0.02 m株高层光照度>冠层光照度；饱果期：地表温度>冠层光照度>1/2株高层光照度>0.02 m株高层光照度。【结论】花生冠层温度日变化与地表温度密切相关，到生育后期，冠层光照度也对其起重要作用。
【Objective】This study aimed to reveal the mechanism of canopy temperature differences in different genotype peanut varieties by investigating the characteristics of diurnal changes in peanut canopy temperature and the relationships with surface temperature and illuminance.【Method】Diurnal changes (06:00－18:00,every 2 h) in peanut canopy temperature and surface temperature were determined with an infrared radiation thermometer,and canopy illuminance,illuminance of 1/2 plant height layer,and illuminance of 0.02 m plant height layer were measured by an illuminometer at both pod setting stage and filling stage.【Result】Significant differences in canopy temperatures of different peanut genotypes were found.Temperatures of warm-type peanut varieties with high canopy temperature were continuously high,those of cold-type peanut varieties with low canopy temperature were continuously low,and the differences were larger at late growth stage.Diurnal changes of canopy temperature and surface temperature of different temperature-type peanuts were well fitted by cubic polynomials,and diurnal changes of various layers were well fitted with quadratic polynomials.There were significant (P<0.05) and extremely significant (P<0.01) positive relationships between diurnal changes of peanut canopy temperature and surface temperature and illuminance of each layer.However,at different growth stages,the effects of various factors on diurnal changes of canopy temperature were different:At pod setting stage,surface temperature>illuminance at 1/2 plant height layer>illuminance at 0.02 m plant height layer>canopy illuminance,while at pod filling stage,surface temperature>canopy illuninance>illuminance at 1/2 plant height layer>illuminance at 0.02 m plant height layer.【Conclusion】Diurnal changes of peanut canopy temperature were closely associated with surface temperature,and canopy illuminance also played an important role at late growth stage