Environmental stress physiology of agronomic crop plants; effects of water deficits on the physiology, growth, development and yield of agronomic crops; adaptation of crops to environmental stresses; genetic, morphological and physiological characteristics relating to crop avoidance or tolerance of water deficits; crop water relations; nitrogen fixation; photosynthate accumulation and partitioning; evapotranspiration; stomatal activity; techniques for measuring plant water status