Yield of water stressed sugarcane is about 50% of the yield of well watered sugarcane though it is one of the grassy crops that well adapted to the dry environmental conditions. Also, sugarcane shows greater genotypic variation in performance within a water regime as well. Hence, investigation of physiological response which could ultimately determine the yield of the crop under different growing conditions is important to achieve the maximum yield by minimizing the yield gap between actually obtained and genetically determined maximum yields in improved genotypes. However, studying these aspects of sugarcane in plant and ratoon crops under different natural environmental conditions is tedious and time consuming process. Despite the circumstances, this book provides the research background and the findings of the field experiment conducted in seven years period to investigate the effects of soil moisture on growth, physiology, yield and ratoonability of sugarcane under irrigated and rainfed conditions in sub-tropical climatic conditions that could be very useful guidelines for the researchers and university students who engaged in crop physiological studies.