Spice Farming
 
LARGE CARDAMOM (Amomum subulatum)


Introduction

Large Cardamom (Amomum subulatum), a member of Zingiberaceae family under the order Scitaminae is one of the main cash crops cultivated in the sub-Himalayan ~tate of Sikkim and Darjeeling District of West Bengal covering an area,of about 30,000 ha. The annual production varies from 5000-5500 metric tonnes . It is also cultivated in parts of Uttaranchal and in. some other North Eastern States. Nepal & Bhutan are the other countries where large cardamom is cultivated. It is used as a spice and in several ayurvedic preparations. It contains 2 to 3% of essential oil and possesses medicin.1 properties like carminative, stomachic, diuretic, cardiac stimulant, antiemetic etc.
 
Climate and Soil

The crop grows well under the shade. of forest trees in the sub Himalayan mountains at altitudes ranging from 1000 to 2000 m. above mean sea level with rainfall of 3000 to 3500 mm distributed in about 200 days a year. The crop is at present grown in some relativelydrier shadow areas also where the productivity is much low. Cultivars suited to higher altitudes can tolerate lower temperatures and those suited to lower altitudes to marginally higher temperature regimes. Deep and well drained soils with loamy texture are best suited. Large cardamom soil is generally rich in organic matter and nitrogen, medium in available phosphorous and medium to high in available potash. pH ranges from 4.5 to 6.0. Even though the crop can be grown in undulating and steep terrains, land with moderate slope is preferred.

Cultivars

There are mainly five popular cultivars viz. Ramsey, Sawney, Golsey, Varlangey and Seremna. Bebo, Boklok Tali, Jaker, Belak are the other cultivars found in Arunachal Pradesh

1. Ramsey

This cultivar is well suited to high altitudes above 1515 m a msl and can be cultivated even in steep slopes. The variety is identified by the maroonish colour of the tiller and narrow leaves. Plants are 1.5 to 2.0 m tall, robust with large number of tillers. Flowering starts in May and crop is ready for harvest by OctoberNovember. Capsules are smaller in size with 25-40 seeds. It is susceptible to viral diseases like Chirke & Foorkey

2. Sawney

It is a widely adaptable cultivar, which is most suited to medium and high altitude areas of 1350 m a msl and above. Plants are 1.5 to 2.0 m tall, robust in nature, leaves are ovate and broad and the colour of tiller is similar to Ramsey. Capsules are bigger and bold with 35-50 seeds. Flowering starts from March to May and harvest begins in September-October and may extend upto November in high altitude areas. The cultivar is susceptible to both Chirke and Foorkey diseases.

3. Dzongu Golsey

It is suitable to areas below 1500 m a msl and is very specific in Dzongu area of North Sikkim and the plant height is 1.0 to 1.5m and not as robust like other cultivars. Unlike Ramsey and Sawney, the tillers are green in colour and the leaves are narrow and erect. Capsules are big and bold and contain about 50-70 seeds. Flowering starts in March and harvesting is done in September-October. It is relatively toleJant to Chirke but susceptible to Foorkey and leaf streak diseases.

4. Seremna
The cultivar is grown in a small pocket of the Hee-Gaon, West Sikkim, at low altitude and is known for its high yield potential. Plants are 1.5 to 2.0 m tall, tillers are green and leaves are mostly drooping, hence named as 'Seremna'. On an average 2-3 spikes in each productive tillers with about 10 capsules in each spike and 65-70 seeds per capsules is recorded.
5. Varlangey

This cultivar is found to grow in mid and high altitude areas. Its yield performance is exceptionally high at high altitudes. Plants height is 1.5-2.5m, robust type and resembles Ramsey with narrow leaves having wavy margins. The spike and productive tiller ratio is relatively high in this cultivar. Size of the capsule is bold with 50-70 number of bold seeds. Flowering starts in May at medium altitudes and during June-July at high altitudes. Consequently harvesting is delayed upto the end of November in high altitudes

Improved Selection.

The regional station,of the Indian Cardamom Research Institute under the Spices Board has conducted exploratory survey of the large cardamom plantations in Sikkim and Darjeeling district and identified a few high yielding selections. They are under evaluation in different locations. The following are the important ones.
Selection
*SBLC 5
SBLC 47 SBLC 42 SBLC 44 SBLC 50
SBLC 51
 Cultivar
Sawney
Varlangey Golsey (Dzo(1gu) Seremna Sawney
Green Golsey
 Altitude'adaptability
Medium to High High
Low
Low
Medium to High Low

low: less than 975 m a msl; Medium: 975-1515 m a msl; High: More than 1515 m a msl

* Spices Board Large Cardamom (SBLC )
Propagation
Propagation of large cardamom is done through seeds and suckers. The Propagation through seeds enables production of large number of seedlings. Virus diseases are not transmitted through seeds and therefore the seedlings are free from viral diseases, if adequate care is taken to isolate and protect the nursery from fresh infection. Plants raised from seeds need. not necessarily be high yielders even if they are collected from very productive plants due to cross-pollination. The major pollination is wild Bees, even though honey bees also playa role in pollination. Planting suckers, on the other hand, ensures true to type and high productivity .if they are collected from high yielding plants.
A. Propagation through seeds

Seeds are collected from high yielding and well-maintained plantations free from viral diseases. Well matured" capsules from bottom and middle position .of the spikes are selected for extraction of seeds. After dehusking, the seeds are mixed with sand and rubbed with hand and then washed with water to remove the mucilage completely. Once the water is completely drained, the seeds are mixed with wood ash, dried in shade and sown in the primary nursery. The seeds maybe sown immediately after extraction for maximum germination. Normally the germinationpercentage is only 20-30% and to be sown immediately after drying under shade. Treatment of seeds with acid gives early, uniform and better germination.

The seeds are treated with 25% nitric acid after removing the mucilage (25 ml of concentrated nitric acid mixed with 75ml of water to make 25% nitric acid). The seeds may be completely immersedhthe acid and stirred well for 10 minutes. The acid is then drained out. The seeds are washed thoroughly in running water to make it free of acid.
i) Primary nursery
Seeds are generally sown in September-October. Seed beds are prepared in well-drained soil dug to a depth of 30 cm and left for weathering. Raised beds with 15 to 25 crn height, 1 m width . and convenient length preferably 6 m are prepared. Well decomposed cattle manure is mixed with the soil and the surface of the bed is made to fine tilth. 80-100 g of seeds per bed is sown in lines across the bed at a distance of 10 cm. Seeds are covered with fine soil and mulched with paddy straw/dry grass (10-15 cm thick). Watering is done at regular intervals to keep the surface of the bed moist. Germination of acid treated seeds commences after 25 to 30 days of sowing. When average germination is noticed the mulch materials are removed. The inter space between rows is then remulched with chopped paddy straw. Shade pandals are immediately erected by using bamboo mats/reed mats or agro-shade nets. The beds are watered regularly and weeding is done as and when required. When the seedlings attain 3 to 4 leaf stage, they are transplanted to secondary beds.
ii) Polybag Nurseries
Polythene bags of 15cm x 15cm with perforations at the base are used for planting the seedlings. The bags are filled with potting mixture of soil, sand and cowdung in the ratio of 4: 1: 1. The bags filled with the mixture are arranged in rows of oneMmetre width and in convenient length under shade pandals. Seedlings with 3 to 4 leaves are planted inthe bags in April~May and watered regularly. They become ready for field-planting in 10-12 months.
Hi) Secondary Nursery
Beds of size 15 cm in height and 100 cm width with convenient length are prepared and well-decomposed cattle manure is mixed with the soil and an even surface is formed. Seedlings with 3-4 leaves are transplanted to the beds in May-June at spacing of 15 cm between them. The inter-space is mulched with chopped paddy straw or dried leaves. Over head pandal is erected for providing shade; the soil is kept moist with irrigation. The seedlings once attain a growth of 45 to 60 cm height with 2 to 3 tillers, are planted in the main field during June-July of the subsequent year.
B. Sucker multiplication nursery
As mentioned earlier suckers should be generated only in sucker multiplication nursery where adequate precautions are taken to ensure that virus diseases are not transmitted through the suckers produced. The site for such a nursery should be located at least 500 m away from large cardamom planations. They are established either under the shade of forest trees or under shade pandals with 50% shade by using black agro shade nets. Trenches of 30 x 30 cm are prepared at convenient lenghts with an interspace of 30 cm. Well decomposed cattle manure or composts mixed with the soil and the trenches are filled to the brim before planting, the suckers from high yielding disease free planations with one grownup shoot with an emerging bud are planted at 30 cm apart in the trenches. The time for planting is May-June. After planting, the plant base is mulched with dried forest leaves. The multiplication rate in this method is about 1:8 in a year time. The grown up tillers are split into units of one tiller with an emerging bud and planted in the main field during JuneJuly.
C. Micropropagation
For rapid multiplication of elite/high yielding clones, vegetative buds from disease free high yielding mother plants are collected and plantlets are produced through Tissue Culture technique. These plantlets are hardened either in poly bags or in secondary nurseries and once sufficient growth is attained can be planted in the main field during June-July.
Planting
Large cardamom grows well in forest loamy soils with gentle to medium slopes. Water logged condition is detrimental to the growth of the plants. It performs well under shade. Utis (Alnus nepalensis) is the most common and preferred shade tree for large cardamom. The other species of shade trees are Panisaj (Termalia myriocarpa), Pipli (Bucklandia sp.), Malito (Macaranga denticulate), Argeli (Edgeworthes gardneri) , Asare (viburnus eruberens), Bilaune (Maesa cheria), Kharane (Symplocos sp.), Siris (Albizzia lebbeck), Dhurpis and Khasi Cherry, Katuse, Faledo (Erythrina indica) Jhingani (Eurja tapanica) Chillowne (Schima wallichi) (castanopsis sp)
Land Preparation
Planting is done during June-July when there is enough moisture in the soil. The land selected for planting is cleared of all under growth, weeds etc. for new planting or if it is replanting, old plants may be removed. Pits of size 30 x 30 x 30 cm are prepared on contour at a spacing of 1.5 x 1.5 m after the onset of monsoon showers. Wider spacing of 1.8 x 1.8 m is recommended for .robust cultivars like Sawney, Varlangey, Ramsey etc. The pits are left for weathering for a fortnight and then filled with topsoil mixed with cowdung or compost @ 1-3 kg per pit. Seedlings/Suckers are planted in the centre of the pits. Care should be taken not to plant the seedling/rhizome very deep in the pit. After planting the seedling/ suckers may be staked and the base of the plant is mulched with dried leaves.
Manuring
For a sustained production the soil fertility should be maintained to its optimum. Well decomposed cattle manure/ compost or organic products, non-edible oil cakes may be applied @ 2 kg/plant atleast once in two years in April- May. If all the crop residues are recycled in the plantation, application of inorganic fertilizers may not be necessary. In plantations with very high productivity, fertilizers @ 20:30:40 kg NPK per hectare may be applied in two split doses with full ofP and half dose of N & K in April and half dose of N & K in September. Mulching the base of plants after application of the second dose, helps the plants in the intake of nutrients.
Weeding
Weed control in the plantations is important for the maximum utilization of the available soil moisture and nutrients by the plant. Three rounds of weeding are required for effective control of the weed growth in the initial two to three years. Weeding can be either hand weeding or sickle weeding depending upon the intensity of weed growth. From around the plant base the weeds can I)e pulled out by hand and the weeds in the inter space need only be slashed with sickle. Clean weeding may be avoided. While weeding, dried shoots and other trashed materials can be used as mulch around the plant base to conserve soil moisture in the ensuing dry months, and to prevent weed growth around the plant base.
Soil and moisture conservation
This crop is mainly grown in highly steep terrain. The topography and climatic condition permits soil erosion to a considerable extent. Intensive operations, which loosen and expose soil, will increase soil erosion and therefore only minimum tillage operations should be followed. As far as possible contour terraces may be made well before taking up planting operations. This helps in reducing soil erosion and soil moisture conservation. Though contour terrace making expensive and requires high initial investment, the long term benefit will be more to compensate the initial extra expenditure.
Irrigation
In some of the large cardamom plantations, water sources are available which can be exploited to irrigate the crop by gravity flow, either through pipes, sprinklers or flood irrigation through open channels. It is observed that productivity is higher in plantations where irrigation is provided. For sustainable and better yield the plants may be watered during dry months. Depending on availability of water sources hose or sprinkler or flood irrigation through channels can be adopted. Hose irrigation can be done @ 40-50 litre per plant at fortnightly intervals. In case of sprinkler irrigation equivalent to 35-45 mm of rain at fortnightly interval is recommended.
Pests
Although there are many species of insects and pests, large cardamom is free from the attack of any major pests except for the sporadic incidence of leaf eating caterpillars. Aphids are found in most of the areas, which transmits virus diseases viz. Chirke and Foorkey.
Leaf Eating Caterpillar
Initially the caterpillar of the moth, Artona chorista feeds on the leaf lamina from under surface of the leaf and finally defoliate the leaves completely leaving only the midribs. Their incidence is noticed in May-July and October-March. Eventhough effective chemical control measures are available (Quinalphos 25EC @0.05% or Endosulfan 35EC @ 0.05%), the use of insecticide is also not advisable and hence not recommended. At present these insects are kept under control by their natural enemies. Once insecticides are used to manage any sporadic incidence, the natural enemies will disappear which may lead to out break of these pests in epidemic form. It is therefore recommended that the plantations may be inspected during May-July & OctoberMarch and the infected leaves along with caterpillars are collected
and destroyed by burning.
Diseases
Problem due to fungal or bacterial diseases are seldom reported in this crop. Only minor diseases like leaf streak or rot diseases are found in isolated areas. The major threat to large cardamom is the widespread occurence of the viral diseases; viz; Chirke.and Foorkey. The diseases are seen throughout the large cardamom growing tracts of Sikkim and Darjeeling District of West Bengal. They cause considerable crop loss. Spread of Chirke is faster than Foorkey.
Chirke
The symptoms are characterized by mosaic appearance on the tender leaves with pale streaks, which slowly turns into' brown, resulting in withering and drying of the plants. Growth and yield of affected plants gradually decline and ultimately they perish. The disease is transmitted by the insect vecto (aphid). It also spreads by planting infected suckers. Transporting of infected suckers from one area to another leads to spread of this disease. The disease is also transmitted mechanically through knife used for harvesting.
Foorkey
Numerous small tillers appear at the base of the affected plants, which become stunted and fail to give any yield. Even inflorescence also noticed to produce unproductive spikes.
Management of viral diseases

Being a viral disease, the affected plants cannot be cured~ but the losses can be minimized by adopting appropriate management practices.

  • Keep constant vigil to detect disease affected plants.
  • Adopt regular roughing of infected plants as soon as symptoms appear ( uproot and destroy affected plants). Repeatdetection and roughing at regular intervals.
  • Use seedlings produced in certified nurseries.
  • Propagation through suckers is recommended only through certified multiplication nurseries
Harvesting and Curing
The indication of time of harvest is when the seeds of topmost capsules turns brown. As soon as the said colour appears and to enhance maturity bearing tillers are cut to a height of 30-45 cm and left for another 10-15 days for full maturity. The spikes are harvested by using special knives known as 'Elaichichhuri'. The harvested spikes are heaped and capsules seperated and dried. The cured capsules are rubbed on wire mesh for clearing and removal of calyx (tail).
Traditionally cardamom is cured in Bhatti, where the capsules are dried by direct heating. Under this system the cardamom comes in direct contact with smoke which turn$ the capsules to dark browner black colour with a smoky smell. improved curing techniques are presently availab.le by which cardamom is processed to give better quality and appearance. One such method is ICRI Spices Board improved bhatti system of curing in which cardamom is dried by indirect eating at 45-50oC
Packaging

The properly dried capsules should be allowed to cool and then packed in polythene lined jute bags. The bags may be stored on wooden platform to avoid absorption of moisture, which may result in fungus growth damaging the stored produce.