Firstly, the extinction coefficient for global solar radiation (Extgr)can be estimated as:

where Extgr is extinction coefficient for global solar radiation (unitless) and Extdiff is extinction coefficient for diffuse light (unitless).
The potential transpiration rate can be calculated with the following equation:

where Trpot is maximum crop transpiration rate (cm d-1), ET0 is potential evapotranspiration rate (cm d-1), Extgr is extinction coefficient for global solar radiation (unitless) and LAI is leaf area index (m2 m-2).
Created with the Personal Edition of HelpNDoc: Write eBooks for the Kindle