To achieve maximum crop yield, factors influencing growth must be identified, evaluated and limiting ones overcome. Limits to growth will be revealed by studying the crop in terms of its physiology, ecology and particularly its response to competition. Lack of information on growth and yield of fodder beet prompted initiation of the work described in this thesis. Crop development and yield as influenced by inter and intra specific competition was measured by varying the density of fodder beet plants in pure stands and in association with weeds.