Episodic growth of Ligustrum japonicum Thunb. plants was determined by
measuring total shoot and root fresh weight nondestructively. Episodi
c growth patterns were apparent in shoot elongation, shoot and root fr
esh weight as a percent of total fresh weight, shoot and root relative
growth rates (RGR(s) and RGR(r)) and two-dimensional measurements of
the root system. Increases in root growth and initiation of lateral ro
ot branching were coincident with changes in percent of total fresh we
ight in the root and RGR(r). The rate of fresh weight gain of roots, s
hoots and the whole plant increased continuously throughout two experi
ments and thus episodic growth patterns were not apparent from these v
alues. Alternating episodes of shoot and root growth, which is shown b
y percent fresh weight allocation and RGR, did not directly correspond
to shoot elongation and cessation of elongation. Continuous, nondestr
uctive measurement of total shoot and root growth reveals important ch
anges in growth which may be obscured by other measurement techniques.