“This is the situation I often see: a grower has a climate system but is not getting the optimal results. So they look for another system to complement their production and hopefully get better results. However, if you don’t find the right balance between these systems, you are not getting the best out of them and could even run into problems,” says Vincent Kickert of ARC Technology. As a climate specialist, Vincent helps develop new systems and cultivation projects. In addition, he helps growers who are not getting the desired results. “Often it is not because they have the wrong systems. More often it is because there is no harmony between the elements that should work together. The importance of air movement is often underestimated.”

Vincent Kickert at work in the greenhouse

Air movement
Why is good air circulation so important? “Air moves upwards. In a greenhouse, the plant evaporates moisture into the air. Not only does the air become more humid, it also becomes colder and heavier, creating a microclimate. From this microclimate, the air then absorbs heat and moves upwards,” explains Vincent. “The more air circulation that passes through the plants, the more evaporation is stimulated. When the air circulation is right, the air flows through the plants, over the leaves, and brings CO2 to the leaves, which stimulates growth. The result: a faster growing plant with better results.”

But what happens when the air movement is not done properly? “If the air movement is not homogeneous, one plant in the greenhouse will get more air movement than another plant. This then leads to irregularities in the harvest. Everything has to be even and balanced to get the best result from your systems and your harvest.”

Two different varieties in the same climate. “To see and understand why one variety survives and the other does not, the cultivation specialist and the climate specialist must work together to find the connection,” says Vincent.

Active air movement through a plant will result in differences in activity and evaporation. More evaporation will result in cooler plants, giving a quick insight into how uniform a plant looks in a greenhouse.

Vincent still encounters growers who do not consider the impact that a different component can have on the climate. “More light means different values. Different CO2 values ​​mean different values. So that also has to be taken into account when you incorporate a new climate component into cultivation. How big will the deviation in the climate be and do the different systems work harmoniously together?”

For example, Vincent worked with a grower who had a chiller on one side of the greenhouse and a dehumidifier on the other. “On one side, cold and humid air is blown onto the plants. On the other side, the plants get warm and dry air. Such conflicting components make it difficult to achieve good results. Adding a new climate system may seem like an improvement to your grow. But if the different components are not properly coordinated, it can even lead to a setback.”

“Similar to a ‘flat’ plant like lettuce, a tomato also has its temperatures. Where it is visibly colder at the bottom (also due to active cooling being blown in from below), a gradient can be found across the plant. The vertical gradient is rarely the biggest problem, but the gradient between front and back more often leads to an uneven growth rate. Plants that are structurally colder fall behind, or the warmer plant is too warm and stops due to stress. To balance the climate, several components must work together harmoniously,” explains Vincent.

Basil in a vertical farm. “When the climate is out of balance, several problems can occur simultaneously. In a single photo, you can see efflorescence of the plant/leaf, bulging of the leaf to protect it from drying out, and hollowing of the leaf to reduce incoming light and increase evaporation. Three different problems, all caused by a climate imbalance and air movement that is not timed to support the plant at the right time.”