Environmental constraints to net primary productivity at northern latitudes: A study across scales of radiation interception and biomass production of potato

•Scale study of plant growth with CASA: NPP=RUEopt×Ipar×environmental constraints.•Field-, air- and spaceborne data provided comparable estimates of Ipar and NPP.•Maximum air temperature and diffuse radiation were major environmental constraints.•RUEopt of potato ranged from 4.19 to 4.98 g MJ-1 in relation to scale.•Potential to extend approach for quantifying fertilization and irrigation need.