The book examines principles, theories, mathematical models, and experimental observations concerning plant responses to environment that are relevant to the development of improved crop cultivars and management methods. It illustrates the importance of considering emergent plant properties as well as reductionist approaches to understanding plant function and adaptation. Plant physiological and developmental responses to light and temperature, and plant water relations are considered in detail. Dr. Hall also describes climatic zone definitions based on temperature, rainfall, and evaporative demand in relation to plant adaptation and the prediction of crop water use. Irrigation management and crop responses to salinity, flooding and toxic levels of boron and aluminum are considered. Crop responses to pests and diseases as they interact with crop responses to physical and chemical aspects of the environment are examined. The book concludes with analyses illustrating the relevance of crop responses to environment to plant breeding.