Agriculture Reference
In-Depth Information
(a)
(b)
Fig. 10.8.
Mango tree showing profuse and uniform
fl
owering (a). Trees are
managed to less than 2 m. When the fruits are about 7 cm across, the tree is sprayed
with fungicide to control fruit diseases, the fruits are thinned and the selected fruits
are bagged (b). One fruit has 6-8 leaves subtending it on the branch.
same time. For this, peripheral pruning is done all over the canopy, removing
the tips of the last growth, including leftover fl oral peduncles, which have
an inhibitory ef ect on future fl owering. This pruning will force the tree to
produce new growth, simultaneously resulting in more uniform fl owering,
since all new shoots are of the same age and in a similar physiological stage.
This pruning should be rather light to avoid a strong tendency to get a second
vegetative fl ush too soon, since this would not allow enough time for the shoot
to rest and become reproductive. It is done soon after harvest, and it is the fi rst
step in the process of fl ower induction.
Fertilization
One of the basic considerations for fertilization amount and time of
application is the growth and fl owering cycle of the tree (Fig. 10.4). During the
fi rst 3 years, approximately 113-227 g per tree of a complete (NPK) fertilizer
is applied three times a year. From the fourth year, trees are considered to
be mature, as they will begin to produce commercial yields, and fertilizer is
applied twice a year. One application is made when the fi rst infl orescence
begins to appear and the second immediately after harvest, to promote a new
vegetative fl ush. Proper placement is important in ground application, as the
highest feeder-root density is approximately 90-175 cm away from the trunk
to a depth of 20 cm. Irrigation is necessary whenever fertilizer is applied.
The major mango-growing countries have usually developed their own
fertilizer ratios and amount to be applied. Complete fertilizers, with an oxide
ratio of approximately 15:15:15, are usually recommended in Hawaii (Yee,
1958). In Florida, a good crop can be obtained by providing 1.4-1.8 kg of N
and K/tree/year to mature trees (Malo, 1976). Using the triple-15 fertilizer,
