New analyzing method of laser induced fluorescence induction kinetics for indoor trees with low-irradiation stress

Laser induced chlorophyll fluorescence induction kinetics provides a simple and non-destructive method for making a diagnosis of indoor plants. This study aimed at developing new parameters related to the laser induced fluorescence induction kinetics for detecting stress imposed on indoor trees mainly due to low irradiation conditions. Evaluating new parameters required only 25 s for each measurement. The new parameters referred to the shape of the second maximum in the induction kinetics. In an experiment lasting over a year using Cinnamomum camphora both outdoors and in a chamber, two of the new parameters showed clear seasonal variations for the outdoor trees and almost constant values for the indoor trees. The values for the indoor trees differed according to the light environment of each tree. These results strongly suggested that the new parameters could be applicable to practical diagnosis of indoor trees.