The improvement of crop species has been a basic pursuit since cultivation began thousands of years ago. To feed an ever increasing world population will require a great increase in food production. Photosynthesis is directly related to plant growth and crop production. Any fluctuation in the photosynthetic activity imposes great threat to crop productivity. Enormous efforts are made all over the world to document as well as use these resources. Due to the environmental fluctuations plants are often exposed to the different environmental stresses leading to decreased photosynthetic rate thus leads to problems in the plant growth and development. Photosynthesis, Productivity and Environmental Stress covers all the topics related to photosynthesis, whether it is terrestrial or aquatic. The book chapters focus on the basic effect of environmental fluctuations, discussing photosynthesisunder both controlled and stressed conditions. New techniques like transgeneics, proteomics, genomics, ionomics, metabolomics; micromics etc. related to photosynthesisare alsodiscussed in the book.