Production of quality planting materials
Cardamom can be propagated vegetatively and by seedlings. For vegetative propagation,
rhizomes with not less than three shoots are used. Plants propagated vegetatively
come to bearing one year earlier than the seedling-propagated plants. But this method
has the disadvantage of spreading the ‘katte' disease, which is of viral origin.
This disease is not transmitted through seeds. Hence in areas where the disease
is widespread, it would be safer to use seedlings for propagation.
Seed propagation
Vegetative propagation has the disadvantage of spreading the ‘katte’ disease, which
is of viral origin. This disease is not transmitted through seeds. Hence in areas
where the disease is widespread, it would be safer to use seedlings for propagation.
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Nursery
Ripe capsules of the desired cultivar are collected from high yielding plants during
September-October. The seeds are extracted by gently pressing the capsules.
In order to increase the germination percentage, seeds can be treated with concentrated
sulfuric acid or nitric acid for not more than two minutes. The extracted seeds
are washed in cold water four times to remove the mucilaginous coating. The washed
seeds are drained and mixed with ash and allowed to dry in shade for 2 or 3 days.
The seeds should be sown in the nursery within a fortnight. Sowing in September
is the best for high germination. Sowing during southwest monsoon and winter should
be avoided.
When it becomes necessary to store the seeds, it is advisable to store them in capsule
form. It can be preserved in this form for one month, without deterioration of viability.
Polythene lined gunny bags can be used for this.
In Kerala and Tamil Nadu, 18-month-old seedlings are used for planting. The seeds
are sown in primary nursery from where the young seedlings are transplanted to a
secondary nursery and maintained for one year before planting in the main field.
Primary nursery
The nursery site is selected in open, well-drained areas, near
a source of water. The land is dug to a depth of 30 cm, cleared of all stubbles
and stones; and clods are broken. Beds of size 6 x 1 x 0.3 m are then prepared.
Jungle soil is spread in a thin layer over the nursery bed. Seeds are sown on the
bed in lines. For an area of 1 m 2 , 10 g of seed is required. The seeds are covered
with a very thin layer of fine soil. The nursery bed is mulched with dry grass.
Potha grass ( Grenetia stricta ) commonly seen in high range areas is a
suitable material for this purpose. Grass is spread to a thickness of about 2 cm.
Paddy straw can also be used for mulching. After sowing, beds have to be watered
every day in the morning and evening. The mulch should be removed on commencement
of germination. The seedlings have to be protected by providing shade pandals. Regular
watering, weeding and protection from pests and diseases are to be attended to.
During June-July, seedlings from the primary nursery are transplanted to the secondary
nursery.
Secondary nursery
After preparing the site properly, form nursery beds of 6 x 1 x
0.3 m. Mixing of well decomposed cattle manure and wood ash with the top layer of
the soil will help the seedlings to establish well and to grow vigorously. During
June-July, the seedlings from the primary nursery are transplanted at a spacing
of 25-30 cm. Shade pandals should be provided before transplanting. Overhead pandals
or individual pandals for each bed may be erected. Mulching the bed with dry leaves
will help to conserve soil moisture. Regular watering during dry months, weeding,
application of fertilizers, control of pests and diseases and mulching are the essential
operations for the maintenance of the secondary nursery. One month before uprooting,
the pandal should be removed to encourage better tillering.
Polybag nursery
Polybags can be used for raising secondary seedlings. For such
nurseries, seeds are to be sown in beds in primary nurseries in September and transplanted
to polybags in December-January. Black HM/HDP bags of 20 x 20 cm size and thickness
of 100 gauges with 3 to 4 holes at the bottom can be used for this purpose. Fill
the bags with potting mixture in the ratio of 3: 1: 1 jungle top soil, cowdung and
sand and arrange them in rows of convenient length and breadth for easy management.
Seedlings at three to four leaf stages can be transplanted into each bag (one seedling
per bag). Adequate space has to be provided in between the bags for better tillering.
These seedlings would be ready for planting in June-July. In this case, nursery
period could be reduced by 6-7 months.
The advantages of raising seedling in polybags are:
Seedlings of uniform growth and tillering can be obtained.
Nursery period can be reduced to five to six months after transplanting
the seedlings as against 10 to 12 months in the secondary nursery.
Better establishment and growth of seedlings in the main field.
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Rhizome multiplication
This may be taken up from the first week of March to the first fortnight of October.
The site is selected in open, gently slopping and well-drained areas near a source
of water. Trenches of 45 cm width, 45 cm depth and convenient length are taken across
the slope or along the contour 1.8 m apart. They are filled with equal quantity
of humus rich topsoil, sand and cattle manure. Uproot a part of the high yielding
disease free mother clump identified in the plantation. Trim the roots and separate
the suckers so that the minimum planting unit consists of one grown up tiller and
a growing young shoot. Plant them at a spacing of 1.80 m x 0.60 m in filled up trenches.
Provide sufficient mulch and stake each planting unit. Provide overhead pandal as
in the case of seedling nursery and remove shading material with onset of monsoon
rains. Provide irrigation once in a fortnight and adopt necessary plant protection
measures. Apply fertilizers @ 100:50:200 kg/ha N: P2O5 : K2O
in six splits at an interval of two months. Apply neem cake @ 100-150 g/plant along
with fertilizers. On an average, 20 to 30 suckers / initial planting unit can be
produced within one year of planting. Care should be taken to identify and collect
mother clumps only from areas totally free from 'katte' disease.
Soil treatment in nursery
It is recommended that the primary and secondary nursery soil may be drenched with
formalin 2% solution and covered with polythene sheets for 3 days. Planting should
be taken up only 15 days after treatment to avoid phytotoxicity.
Pests and diseases in the nursery
See the details given under Plant protection
in the nursery
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