PHYSIOLOGY OF YIELD EXPRESSION IN SUNFLOWER

This paper evaluates currently available information on the physiology of sunflower (Helianthus annuus L.) in the context of field growth responses and the determination of crop yield, It deals with phenology, water economy, mineral nutrition, carbon fixation and partitioning, yield formation, and seed quality. Attention is drawn to information on intraspecific variation of individual traits to highlight the possibilities that exist for cultivar adaptation and improvement. Properties commonly attributed to this crop such as high photosynthetic capacity, profligate use of water and low water-use efficiency are evaluated.