Interception of PAR and relationship between FPAR and LAI in summer maize canopy

According to our observation under clear and cloudy days during growing season, we analyzed the diurnal changes of the incident PAR, the reflected PAR of canopy and soil, the transmitted PAR, the reflectance of soil, and the absorbed photosynthetically active radiation (APAR). FPAR at an interval of five minutes and the average value of a day are also calculated according to each PAR component in canopy. Then the relationship between daily variation of FPAR and crop growth periods as well as the variation of LAI was also investigated and a linear relationship between FPAR and LAI was presented.