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CITRUS FRUITS
Citrus thrives well in tropical and subtropical climates.
Some of the best quality oranges are grown in the non-humid,
irrigated, subtropical areas such as the Mountain Province.
It can be grown in our four types of climate but areas with
well-distributed rainfall throughout the year are best. Those
with distinct and long dry periods should bank heavily on irrigation
to raise high quality citrus fruits.
Fields of citrus in the country are generally low. Citrus
plantations are run on modern and intensive technology to allow
their produce to compare favorably with those of developed countries.
VALUE
Citrus fruits are rich in vitamins, especially vitamin C.
Its mild acid and bitter taste favorable to digestion and blood
circulation. Citrus peels are rich in pectin, valuable in making
jellies, marmalades, candies, jams and pharmaceutical preparations.
VARIETIES
Several species are highly adapted to the country. The most
important include calamondin, mandarin, pummelo, lemon and lime.
| Calamondin |
Locally known as "kalamansi"
or "kalamundin", this is a small tree with upright
branches. Its leaves are broadly oval, dark green above and pale
green below. Its fruits are small subglobos, ranging from 0.3
to 3.5 cm long and 3.8 to 4.5 cm in diameter. Each fruit has
7 - 10 segments with a very thin rind. The juice is acidic and
usually use for flavoring. |
| Mandarin |
Actually it is native to China.
Its local names are "sintones" or "dalanghita".
This tree has a dense crown with slender branches, with a few
row to ovate and pointed. The fruit is flattened and turns yellow
or reddish orange when mature. It consists of 10 - 14 segments
easily separated from one another to form an open core. The rind
is loose and can be easily removed. Its popular varieties include
Szinkom, Ladu, Batangas, and King. |
| Pummelo |
It originated from the Malayan and
East Indian archipelago. Locally, it is known as "lukban"
or "suha". Its tree which is medium to large and spreading,
bears fruit that is large, round to pear-shaped and with a thick
and spongy rind. The segments usually open at the sutures. The
flesh is commonly firm with large vesicles and with low to high
juice content. It usually matures from October to March. Its
outstanding varieties include Amoy, Siamese, Pink and Suiwui
Luk. |
| Sweet Orange |
Locally called "dalandan"
or "kahel", it originated from China. Its varieties
cultivated in the country are Hamlin, Pineapple and Valencia.
Its typical tree is moderately vigorous, medium-large and productive.
The fruit is usually medium-sized and spherical to slightly obovate.
Valencia type which is of excellent quality may be seedless pr
may have five to six large seeds. |
| Lemon |
It is grown primarily for its acidic
juice. The tree is medium-sized, elliptical to oblong, sometimes
obovate with a short neck or low collar at the base. It usually
has 10 segments and the rind turns yellow when it ripens. Its
flesh is greenish yellow, tender and juicy. Best commercial varieties
grown here are Eureka and Lisbon. |
| Lime |
Locally known as "dayap",
this common tree is small and bears seedy small fruits with a
very thin, aromatic rind. Its flesh is juicy and very acidic. |
PROPAGATION
Citrus can be propagated by seed budding, grafting and marcotting.
Commercially, seed budding, which is universally applicable to
all citrus species, is the preferred method. Although grafting
and marcotting produce satisfactory materials, and therefore
may be recommended only for small-scale propagation.
Shield budding unites a desired scion variety with a suitable
rootstock. Success depends on the skill of the propagation and
the conditions of the scion and the rootstock.
Rootstock
- Must be compatible with the scion variety allowing good growth,
long life, good yield and good fruit qualities;
- Seeds must be readily available, preferably high poly-embryonic
to get uniform seedlings and with high percentage and germination;
- Must be adaptable to a wide range of soil depth, texture,
structure, pH, salinity, moisture, and nutrient supply; and
- Must be resistant to soil-borne diseases, such as Phytophthora
grimmosis.
Budwood should be taken from parent trees which:
- Hold a record satisfactory production over a period of a
t least 5 years;
- Are free from systematic diseases; and
- Have true-type fruit characters.
Budwood should be plucked from green, vigorous, second-flush
growth. Its leaves should be clipped and the budwood is collected.
It should be immediately labeled, indicating the name of the
variety, source of budwood, and date of collection. Only freshly
cut budwood should be used. If it needs storage, it should be
kept by wrapping it in moist sphagnum moss or similar materials,
put in polyethylene bag and kept in a cool place. This will last
for 10 days.
Care
- By means of shallow cultivation, the nursery is always kept
free. Weekly, seedlings are sprayed with the appropriate insecticides
to control pests and leaf cutting insects. Every 2 weeks, copper
fungicide is mixed with the insecticide to control diseases.
Once a month, at time of weeding, one (1) level tbsp 5 g urea
is applied around each seedling.
- From a budded plant, tape is removed 2 - 3 weeks after budding.
If the bud looks fresh and green, the lower half of the tape
is left intact until the bud begins to grow. When the budding
reaches about 10 cm, lopping can be done to hasten growth. Only
one vigorous scion should be allowed.
- Cultural practices such as weeding, cultivation, watering
and fertilization should be continued to promote the development
of the plant. To avoid infestation, spraying of appropriate insecticide
should be done every 2 weeks.
Orchard Establishment
- Planting can be done anytime of the year if irrigation is
available. Balled or bare-rooted budlings are planted in holes
big enough and always enriched with a handful of complete fertilizer,
high in phosphorous. Topsoil is used to fill the holes and this
is pressed down firmly to avoid large air spaces. Newly planted
budlings should be watered immediately.
- Planting of citrus follows a certain arrangement in which
trees are set out in the orchard. Systems used include square,
rectangular, triangular, and quincunx. Rectangular and square
systems are to be used where intercropping is to be done.
In rectangular and square systems, the rows of trees are set
at right angles to each other. In a triangular system, trees
are set at the corners of equilateral triangle. In the quincunx
system, four trees are set in a square and a tree is planted
in the center.
Care for the Bearing Groves
Care for the bearing groves is observed through the following:
1. Irrigation. This is important to avoid water
stress. Trees are watered until the rainy season begins. Irrigation
can be through furrow, hose, or sprinkle.
2. Fertilization. Plants need 2 - 3 fertilizer
applications each year.
a. First, when the rainy season begins;
b. Second, during the middle of the rainy season; and
c. Third, when the rainy season is about to end. Fertilizer can
be applied or sprayed.
Fertilizer can be applied directly or sprayed.
Common Role of Fertilization in Orchard for Each Application
| Age (Years) |
N
g/tree |
P205
g/tree |
K20
g/tree |
4
5
6
7
8 |
150
225
300
400
500 |
100
140
200
200
200 |
100
200
300
360
420 |
From The Philippine Recommends for Citrus,
PCARRD
Technical Bulletin Series No. 42, p. 23 |
- 3. Pruning. Pruning means removing diseased
and dead twigs, branches, and leaves which are unproductive and
are less exposed to sunlight. Best time for pruning is during
the dry season or after harvest.
- 4. Spraying. A certain spray program should
be strictly observed. Two or three types of chemicals against
a particular pest should be alternated to avoid developing resistance
of the chemicals.
- 5. Propping and Setting of the Windbreaks.
To prevent the crop from touching the ground and the branches
heavily laden with fruits. Ipil-ipil windbreaks on the windward
sides of the orchard can be set up.
Pests and Diseases
- Many important pests limit citrus growth. A systematic virus-like
disease called leaf molting with its insect nectar was responsible
for the decline of more than half a million citrus trees.
- Efficient pest management simply requires an understanding
of the nature and cause of diseases, conditions that favor the
spread of the diseases and the most effective control measures.
Knowledge of the most common and destructive insect pests therefore
becomes vital.
- To prevent unnecessary injury to plants when using pesticides,
make sure that instructions and recommendations in pesticide
packages and containers are followed.
Harvesting
- Periodically, sampling has to be done to check whether fruits
are ready for harvesting. Generally, citrus trees start bearing
fruits 3 - 5 years from planting and can be harvested 5 - 6 months
from flowering depending on the species and the environment.
Unlike other fruits, citrus does not ripen further after it has
been harvested, so it is important that it is picked at the right
stage of maturity.
- Maturity indices include color, juice content, level of soluble
solid (sugar), titratable acidity, and solids to acid ratio.
Table of Minimum Maturity Requirements for Local Citrus
| Cultivars |
Color
Break |
Soluble Solids
% |
Titratable Acids
% |
Solid to Acid Ratio |
Juice Content
(% by weight) |
Valencia
Ladu hybrid
Ladu ordinary
Pummelo
Ponkan
Batangas mandarin
Szinkom
Calamondin |
25
25
25
50
50
no. req.
no. req.
no. req. |
8.5
9.0
8.0
9.0
9.5
7.5
7.5
no. req. |
0.5
0.6
0.6
0.6
0.5
0.7
0.7
no. req. |
10:1
10:1
8:1
10:1
10:1
7:1
7:1
no. req. |
50
50
50
50
50
50
50
40 |
- Best time to harvest citrus is from 8 a.m. to 3 p.m., when
the dew has dried up and fruits have lost their turgor. Fruits,
which are frigid, are easily bruised resulting in brown patches
on the rind, which indicate direct injury to the oil cells in
the rind. This lowers fruit quality.
- The proper way to harvest citrus is by pulling or clipping
from the stem. "Twist, jerk and pull", experts say,
is the general rule. Use of hand gloves reduces to a great extent
injuries on the peel of citrus.
- Canvas bags of suitable sizes with hooks at the bottom are
best for transporting fruits to large, padded, field containers.
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