Archimedes Plutonium wrote in message ...
[snip]
Perhaps rate of growth is want underlies the yellowish color of Sunburst cultivar. Maybe
Sunburst rate is slower than normal and as such yellow. So slow is yellow, and normal growth is
green and fast is red.

No such relation, red new growth is normally juvenile chlorophylls.
Red new growth does not translate to red fall color: they are
different pigments produced by different means altogether.

--
Chris Green