Increase in sweet cherry fruit equatorial diameter
follows a double-sigmoid pattern consisting of three distinct
growth stages (Fig. 1): an initial phase of exponential growth of
the fleshy mesocarp (stage I) generally assumed to be driven by
cell division; the lag phase, a period of reduced mesocarp growth,
lignification of the endocarp and development of the embryo and
associated seed tissues (stage II); a second period of exponential
fruit growth due to mesocarp cell expansion. The length of each
stage varies with genotype and environmental conditions.