When talking about Plant Empowerment, Hoogendoorn Growth Management means using the information the plant provides to guide your growing processes. An important part of Plant Empowerment is balancing various elements of the growing process. One such element that needs to be balanced is water – balancing irrigation and evaporation to create optimal conditions for the root zone.
Balancing evaporation and uptake is important, because if one exceeds the other it can cause issues for the plant. If a plant’s hydration is lower than the amount of evaporation, for longer stretches of time the plant’s stomata will close to reduce evaporation. This, in turn, reduces the uptake of CO2, which slows down photosynthesis and thus growth.
The driving force of evaporation is always energy, whether this comes in the form of heat, or light, or from the surrounding air. Convective heat transfer, as this transfer of energy via air is called, can only take place if two conditions are met: the leaves of the plant are at a lower temperature than the air, and the air is moving. Temperature difference between leaves and the air in the greenhouse depends on the humidity deficit in the air. If this deficit is too small there is little or no convective evaporation.
Aligning irrigation to evaporation
In order to align irrigation to evaporation, according to Hoogendoorn it is necessary to add up different energy inputs to a total evaporation energy flow. In the Hoogendoorn iSii control software this flow can be summarized over time. Every time a certain sum is reached, the next drip cycle can be triggered, allowing the grower to align irrigation to evaporation.