Thermography and plant physiology.

The temperature of a plant in a climatised room depends on the irradiation level. The use of a thermocamera is valuable for the characterisation of the complicated temperature distributions as can be found, for example, on a leaf in an assimilation chamber. Point measurements of temperature are useful only when the temperature distribution over an object is sufficiently known. The measurement of the radiation temperature of an object behind an infra-red transmitting filter is possible. The temperature distribution over a leaf depends on the gradients in irradiation and air humidity to which it is exposed, on local difference in stomatal opening and on air velocity.