Horticulture Principles and Practices

Tear away
top of peat
pot
Pot with growing
medium and hole
to receive seedling
Plant seedling
with remainder
of pot
FIGURE 9–16 Removing larger seedlings from pots for
transplanting or repotting.
FIGURE 9–17 Transplanting seedlings raised in
peat pots. Since peat is biodegradable, there is no
need to remove peat pots before transplanting.
9.16.2 TRANSPLANTING FROM A POT OR CAVITY TRAY
When transplanting from pots or cells, all one needs to do is position the stem between
a pair of fingers and then invert the pot onto the palm (Figure 9–16). A gentle tap at the
bottom of the pot or tapping the edge of the pot against the edge of a table aids in removing
the plant from the pot. If the roots are pot-bound (coiled over themselves at the bottom
of the pot) due to limited space, they should be loosened before transplanting. An
advantage with peat pots is that, since the pot is biodegradable, there is no need to remove
the seedlings from the pot before transplanting (Figure 9–17).
Transplanting into the field should be undertaken at a good time of day. Freshly
transplanted seedlings need time to establish and resume normal activities. The roots will
not immediately conduct moisture as they did in pots, and hence the plants are in danger
of moisture stress. Transplanting at high noon magnifies this danger. Seedlings should
be transplanted in the late afternoon so that they have ample time to recover before the
next day’s noon temperature.
310 Chapter 9 Sexual Propagation
SUMMARY
Flowering plants produce seed from which they can be propagated. Seeds are products
of the meiotic process (except apomictic seeds, or seeds produced without fertilization)
and hence produce offspring that are not clonal or identical to the mother plant. A seed
contains the miniature plant (the embryo), which is protected by the cotyledon(s). Commercial
seed production goes through four stages (breeders’ seed, foundation seed, registered
seed, and certified seed) before it is made available to growers. Seeds vary in
viability and longevity. Some seeds fail to germinate even under optimal conditions
because of either physiological or structural barriers that induce dormancy. Under such
conditions, seeds may be scarified or stratified to break the dormancy. Other chemical
treatments may be applied to enhance seed germination. Seeds require moisture, air,
temperature, light, and a disease-free environment for germination. Species differ in their
requirements for germination. Some plants can be propagated by direct seeding, whereas
others are transplanted after nursing. Direct seeding is generally easier to undertake,
especially on a large scale. Transplanting ensures good establishment and hastens
crop maturity. Seedlings can be raised indoors while waiting for good weather to plant in
the field.