FRACTURE PROPERTIES OF PLANTS

There is a number of reasons for studying the mechanisms controlling the structural integrity (largely expressed as fracture properties) of plants. The first is in terms of the plant itself—the plant has to be able to withstand the mechanical effects of wind, water, and gravity and grow in such a way that its integral parts remain intact and do not split open unannounced. This may sound a trivial statement, but it is the experience of engineers that it is much easier to design something which breaks than something which does not especially when, as with plants, there is an upper limit (if only an implied one) to the amount of material available for construction. To survive, the plant must, therefore, have mechanisms for resisting fracture (the initiation and propagation of cracks). By contrast, the plant can encourage and direct fracture by laying down abcission and dehiscence layers, which are very brittle. The fracture properties of plants are also important for the animals that feed upon them. Mechanical properties constitute a significant factor in palatability, which, for man, extends to mechanical properties during and after various processes in preparing plants as food. © 1990 Academic Press, Inc.