Testing the hypothesis that mean relative growth rates eliminate the size-related growth differences in tree seedlings

Various hypothetical growth curves were used to evaluate the suitability of using mean relative growth rate (kGR) to compare growth when tree seedlings differ in initial size. Two seedlings were said to be growing according to the same basic growth curve if the only difference between the two growth curves was due to time (Le., the larger seedling was always 2 weeks ahead of the smaller seedling). The k(5R technique eliminated such size-related growth differences when growth exhibited an exponential pattern: y=k + eb+ct (where k=0, t=time, and b and c are constants). The RGR technique did not eliminate size-related growth differences under conditions where k was not equal to zero or when the growth curve was not exponential. Various examples are given to show that RGR usually declines ^ seedling size increases during the first 5 months after germination. Where the RGR value is a function of size, the RGR method of analysis is not suitable for eliminating growth differences related to seedling size