Agriculture Reference
In-Depth Information
and there will be a number of seedlings that come out with a swan-neck-
shaped stem base or root. Seedlings with this condition should be discarded
since they do not become good plants or rootstocks. Only seedlings with
straight stems and roots should be transplanted to the nursery pots or bags.
Plants in nursery containers
Plants left too long in nursery pots or bags normally have deformed root
systems. The main root will reach the bottom of the container and will not
be able to grow through so it will bend and start growing horizontally in a
circular fashion, following the lower rim form of the container. The lateral
roots, upon reaching the walls of the container, will grow around the root
ball and form a sort of peripheral basket or root mesh (see Fig. 3.5b). This
condition is also referred to as root-bound. When transplanted, the root-ball
prevents the development of a good root structure; the plants remain stunted
and are poorly anchored in the soil. Therefore only plants that are not root-
bound or have not stayed in the container too long should be selected and
planted.
Transplanting in the nursery into larger or taller containers that allow
the roots more time before they become deformed is preferable. If planting
material of the desired variety is in short supply, then the deformed plants can
be used. Remove the deformed plant from the container and cut the main root
above the point where it started to bend at the bottom. The lateral roots should
also be cut to disrupt the peripheral root basket, if present, by making several
vertical cuts on the outer part of the root-ball.
Planting
Planting in warm climates can be done almost any time of the year. If the
weather is too cool, planting can be delayed. If no irrigation is available,
planting should be done at the beginning of the rainy season. Some people
recommend adding 20-50 g triple superphosphate in the bottom of the hole,
separated by a 3-5 cm layer of soil from the root-ball.
PRUNING
Pruning fruit trees involves training the tree to the desired shape. The shape of
the trees will depend upon the species and the specifi c management objective.
Several models that are based upon developmental fate of the apices, the
confi guration of the branching points and plagiotropy (horizontal growth)
and orthotropy (vertical growth) of tree axes exist. The growth of the trunk
can be monopodial, rhythmic and indeterminate.
