Solar-induced chlorophyll fluorescence (SIF) offers a promising method to remotely monitor photosynthesis at the canopy and regional scale. However, in order to interpret satellite SIF measurements in a biological context, there needs to be a better understanding of the diurnal dynamics of SIF and photosynthesis under variable stress conditions. Photons absorbed by a leaf can enter photochemistry, be actively dissipated via non-photochemical quenching (NPQ), or be re-emitted as chlorophyll fluorescence. Therefore, having better understanding of NPQ should improve interpretation of SIF. At the canopy scale, we captured diurnal dynamics of SIF and GPP. We then coupled leaf-level measurements of chlorophyll fluorescence, NPQ and photosynthesis and plant water status with canopy-level SIF and GPP to explore the mechanisms controlling diurnal dynamics of fluorescence vs. photosynthesis in a rain-fed maize field situated in upstate New York.