Agriculture Reference
In-Depth Information
mother plant and left to dry for a few days so that the wound forms its scar,
and after that they can be used for a new pineapple planting.
Differences between sexually and asexually propagated
fruit trees
Trees originating from seeds tend to be vigorous since they are in a juvenile
state that does not produce fl owers and fruits. After these plants reach a
certain age and become adults, they are able to fl ower and fruit. For some
fruit trees the juvenile period can last 8-10 years. During this juvenile period,
the plant will grow vigorously and become very large unless subjected to
modern tree management practices. Additionally, trees from sexual seeds are
normally genetically dif erent from their mothers and among themselves, and
potentially have dif erent growth patterns and have fruit of dif erent quality
characteristics, making marketing more dii cult.
Asexually propagated trees are clones of their mother plants and bear the
same type of fruit. Additionally, the material used for asexual propagation is
normally obtained from a plant in the adult phase, not in the juvenile phase.
This adult material will have already fruited and its quality can be evaluated.
The trees obtained from adult plants will fl ower and fruit upon receiving the
external signal that induces fl ower development and will not have a juvenile
phase such as a plant from seed. If no external stimulus is required, they will
fl ower immediately. This earlier fl owering results in smaller trees. In the case
of grafting or budding, the existence of a graft or bud union can restrict the
internal xylem and phloem transport and additionally infl uence tree size
reduction and precocity. Dwarfi ng rootstocks are being sought for species that
normally grow very large.
NURSERY TREE MANAGEMENT AND PLANTING
Tree management starts in the nursery, since many problems in fruit
production can be avoided by just taking care of this phase of development.
Seedlings
At this stage many trees will show twisted or malformed roots or stems due
to the position of the embryo at sowing time. In some species this can be
controlled or reduced by sowing the seed in the correct position. This is
unpractical with some species because of the small seed size, and when the
seeds are polyembryonic (citrus, mango) the orientation of some of the
embryos, relative to the correct position of the seed at sowing, is not normal,
