ABSTRACT
Growth-extending deciduous grafts or leafy grafts, both requiring light levels in the photosynthetically active range can be provided with the correct spectral mix by light emitting diode lamps. Developments in the provision of economical lighting make it possible to consider replacing warm callusing systems by growth chambers or growth houses. Buildings based on those for refrigerated cold stores converted with necessary heating, humidifying and lighting equipment may fulfil the basic requirements for large-scale climate-controlled growth chambers. These are well-insulated and vapour sealed but will require heating, humidifying and lighting for conversion to a suitable structure with the potential to offer optimum environmental control for grafts. A suitably insulated building supplied with heating, cooling and humidification equipment lacks only light to efficiently provide all environmental conditions for grafts. This concept may mean that it will be feasible to provide conditions for grafts in energy efficient, non-traditional growing structures with the possibility that in the future facilities become commonplace.
