This allows the grower to monitor the climate around the plants and whether the stomata of the plants are open.
When the stomata are open, the plants will lose water through a process called transpiration.
Transpiration is linearly related to growth, so open stomata indicate plant growth. When plants’ stomata are open, we also know that Ca, Mg and CO2 are being effectively taken up.

HOW CAN WE SEE PLANTS TRANSPIRING?

Inactive leaf

A LEAF WITH CLOSED STOMATA HAS THE SAME TEMPERATURE AS THE GREY SPHERE, THE INACTIVE LEAF.

Thermal image

THE TEMPERATURE OF A LEAF WITH CLOSED STOMATA IS THE SAME AS THE INACTIVE LEAF.

A LEAF WITH OPEN STOMATA IS COLDER.

Why?

BECAUSE WHEN A PLANT HAS OPEN STOMATA, ENERGY IS LOST BY EVAPORATION, COOLING DOWN THE PLANT.

In practice

AIM FOR LEAVES COLDER THAN THE INACTIVE LEAF, TO ENSURE THE PLANT IS TRANSPIRING.

? Stomata Camera Datasheet and offer for January