PROBLEM TO BE SOLVED: To provide a growth diagnostic apparatus that diagnoses the growth of a vascular plant without using an expensive device.SOLUTION: A growth diagnostic apparatus comprises: internal information measurement systems (1a, 1b, 11) which measure data on internal information showing a growth state of a vascular plant 2a； environmental factor measurement systems (12 to 15, 51a) which measure fluctuation data on an environmental factor affecting the growth state of the vascular plant 2a； and an arithmetic control device 30 which calculates a correlation coefficient between data on the internal information and fluctuation data on the environmental factor. The growth state of the vascular plant 2a is diagnosed by a value of the correlation coefficient.SELECTED DRAWING: Figure 1
