Agriculture Reference
In-Depth Information
or a composted organic matter is used, then it is not necessary to separate the
material and the hole can be fi lled with the mixture of topsoil and decomposed
manure.
The root-ball can be set in place with a 20-cm-wide ring of topsoil around
it. The remaining part of the hole is then fi lled with topsoil, or ideally with
the mixture of topsoil and composted organic matter, and compacted so the
plant stays fi rmly in position, and the root-ball is in close contact with the
surrounding soil medium. This will allow new roots to grow rapidly into the
surrounding soil without problems. If the subsoil is of poor quality, topsoil
from neighbouring areas can be used and then these areas can be backfi lled
with the subsoil from the hole. It should be remembered that most of the
feeder root activity occurs in the upper 50 cm of the soil. Large holes provide
much better growing conditions than a normal hole. When establishment is
dependent upon seasonal rainfall and irrigation is not available, planting
should occur just prior to the wet season. It may be necessary to water the
plants under these circumstances using buckets during the fi rst 2-3 years to
give the plant a much better start.
PLANTING MATERIAL
Often new growers will purchase planting material that is not of the highest
quality or the best variety. This practice leads to poor tree establishment, poor
yield or poor fruit quality. Having to replant an orchard is expensive and it
should be avoided. Plant quality is determined by several criteria.
Plant identity
Most tropical fruit trees are a combination of a varietal scion and a rootstock.
Alternatively, cuttings, air layers or vegetative organs like suckers and
runners are used. For herbaceous fruit trees such as papaya, seeds are used.
It is necessary to ensure the plants are the variety that you want. In grafted
or budded plants the identity of the scion has to be known, and in many cases
it is also very important to know what rootstock was used. Rootstock choice
is crucial for some fruit species, and it has to be a very specifi c variety or type
in order to allow the tree to grow well under determined soil conditions in the
presence of certain plant pests and diseases and to produce good-size plants.
For some species, choice of rootstock is not so crucial, as it serves only to
propagate the desired variety by grafting or budding.
