This congress is the result of a voluntary policy of the French National Committee for Scientific Research (CNRS) to promote interdisciplinarity. Some of the major problems encountered by present research require the collaboration and association of abilities from various disciplines. Plant biomechanics is a typical case, since it requires a synergy between scientists involved in plant biology, the modelling of complex systems, and the mechanics of materials and structures. This field aims at improving the understanding and analysis of: morphogenesis and function of supporting organs in plants; relationships between mechanical functions of cultivated plants and the quality of crops; growth, development. structure and mechanical strength of plant systems relative to modifications imposed by man and the environment; plant mechanical; structural and responsive designs as paradigms, in a biomimetic sense, for man-made applications. During the last few years, this new theme has been developed in North America, Japan and Europe, particularly in Great Britain, Germany and France. The first international congress entirely devoted to plant biomechanics is thus due to the initiative of the national committee. The following collection of voluntary contributions reflects the main axes of the research under development, either basic approaches to morphogenesis and plant growth, or applied research aiming to meet the needs of foresters, the agricultural sector, the food industry and park managers. The level of interaction between specialists in basic and applied knowledge is another strong feature of this congress, which should be, primarily, an occasion to meet others. The full text of invited papers, originally published in two special issues of "Biomimetics", has been added to the document.