 The seed germinates slowly, taking up to
4 months before the shoot appears. During germination,
the single cotyledon (seed leaf) grows inside the seed
cavity. After two weeks, it hardens a little and then begins
to form the first root on the underside, followed by the
shoot on the upper side. It also grows a sheath to protect
the seedling root and shoot from insects and mammals. This
grows with them through the softest of the three eyes at
the base of the shell.
At the same time, the embryo develops
an organ of spongy tissue (technically, the haustorium,
but often called the ‘apple’)
that expands rapidly into the cavity of the nut, usually
filling it completely within four months, although in a
large nut this would take a little longer. It rapidly absorbs
the coconut water, and from the kernel it takes nutrients
at an increasing rate to provide substance and energy for
the growth of the seedling. Because the seedling has this
natural reservoir, it can grow for some time before making
contact with the soil.
When the first green leaf appears,
the seedling can begin to generate its own food by photosynthesis
and there is a period of gradual ‘weaning’ as
the young seedling expands a series of leaves, each larger
than the one before. Each new leaf supplies a greater
share of the energy needs of the seedling, which thereby
becomes less and less reliant on the diminishing kernel
to sustain its accelerating growth.
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