Agriculture Reference
In-Depth Information
bask in the light and out-compete the rest by
suppressing those buds below it, creating
what is referred to as
apical dominance
.
Wherever there is a stem with an active
apical bud going straight up, it will continue
to do so regardless of the buds below it.
There are plenty of people out there who are
like this, and needless to say, they (the apical
buds) should be trained to make sure that
the whole plant can realise its maximum
plant potential (see Figure 1.4).
The apical bud is essential for creating a
strong central leader (trunk) in trees or other
woody plants; however, it needs to be
discouraged to form bushy plants. Successful
lavenders would never have a central trunk, as
their talent lies in forming a rounded shape
in order to carry more flowers. Lavenders are
a shrub, so are naturally inclined to be bushy.
Pinching out the apical bud will ensure that
the bush will branch from the base. This is
often done in the nursery as soon as the
Figure 1.3
This seven-day-old snow pea started with two
meristems. The radicle forms the roots, and the plumule
that forms the above-ground parts. Note the roots are
branching and the seedling mix is clinging to the
microscopic root hairs that draw up water and nutrients.
The plumule is just unfolding its seed leaves that hide a
meristem that gives rise to the rest of the future pea plant.
Buds-apicalandotherwise
Buds form the above-ground growth points
on plants. They contain the actively dividing
cells and plant hormones that produce
growth. Due to the balance of auxins,
however, not all buds were created equal.
Apicalbuds
These buds are those at the very top (apex)
of the plant or plant stem and produce
auxins that keep this top bud extending
towards the maximum amount of light
available. Auxins also inhibit the growth of
side or axillary buds. The apical bud, fuelled
with hormones, gets the priority grab of
water, nutrients and sugars required for
growth. This means that it can grow taller,
Figure 1.4
The most active growth is at the apex of the
plant governed by the apical bud that pushes onwards
and upwards. This is essential for a central trunk in trees.
