This book, in a comprehensive manner, provides an overview of the challenges of increasing crop or agricultural productivity to meet the demands of a growing population, linking descriptions of physiological, ecological, biochemical and molecular activity in plants with their tolerance and adaptation to natural environments. In the case of plants, a stress is an adverse condition or substance that affects or blocks a plant's metabolism, growth, or development. The threat to productivity in crops and agriculture due to these stresses cannot be overstated, nor overlooked, especially in light of climate change. The information covered in this book will be helpful in building strategies to counter the impact of stress on plants. The book also provides an overview of the essential disciplines required for sustainable crop and agricultural production for policymakers, scientists, academics, and students of plant science, agricultural science, environmental science, biochemistry, biotechnology, and related areas.