Photosynthesis is an important target trait to improve crop resilience to different biotic and abiotic stresses. Photosynthesis is a multicomponent process; therefore, it is important to identify rate limiting processes to ensure photosynthetic stability. Therefore, objective of the current research was to determine the underlying physiological processes driving reductions in net photosynthesis in response to (1) nitrogen deficiency, (2) water deficit stress, (3) combined water deficit and N deficiency, or (4) cotton leafroll dwarf virus disease (CLRDD), in field grown cotton. To achieve the objective, five different field studies were conducted, out of which, two studies were on CLRDD, one on nitrogen deficiency, one on water deficit stress, and one on combined water deficit and N deficiency. Net photosynthetic rate (AN) was negatively impacted by all the aforementioned stresses. RuBP regeneration and Rubisco carboxylation co-limited AN due to N deficiency at peak bloom. Lower mesophyll conductance, ETR and RuBP regeneration were the primary drivers of water deficit stress-induced declines in AN. Reduced CO2 availability and Rubisco carboxylation were the major drivers of declines in AN under combined water deficit and N deficiency. Lower mesophyll conductance, electron transport rate (ETR), RuBP regeneration, and Rubisco carboxylation were important contributors to declines in AN due to CLRDD. Across all stresses, carbon loss processes (dark respiration and photorespiration) were either not impacted or they were less negatively impacted than carbon gain process (photosynthesis), as a result, a higher fraction of total carbon fixed was depleted by carbon loss processes under stress conditions. Therefore, these carbon loss processes were also partially contributing to declines in AN. Overall, the underlying physiological processes contributing to declines in AN were dependent on the type of stress prevailing in field grown cotton.