A TRANSPIRATION-BASED CLIMATE CONTROL ALGORITHM
An example of how a plant process can be indirectly manipulated is discussed in this paper, where a transpiration control algorithm is described. The latter is not based on fixed set-points for temperature and humidity within a greenhouse but on a set-point for crop transpiration. This set-point depends only upon the quantity of available radiation. Corresponding set-points for temperature and humidity are deduced from within the algorithm. In fact, many different combinations of the two can provide the desired transpiration rate, once the available radiation is given. The choice of final climate set-points has therefore to be based on the optimization of 'targets' (e.g. net photosynthesis or, ideally, net return for the grower) which are physically possible.
van Meurs, W.Th.M. and Stanghellini, C. (1989). A TRANSPIRATION-BASED CLIMATE CONTROL ALGORITHM. Acta Hortic. 245, 476-481