Large Cardamom Cultivation

LARGE CARDAMOM

(Amomum subulatum Roxb)

INTRODUCTION

The Large Cardamom (Amomum subulatum Roxb) is one of the major export commodities of Bhutan.  As per the national statistics, Bhutan exported 650 Mt dried Cardamom in 2013.  The unaccounted sale through middle man would have occurred similar or more amount.  Depending on the quality of the product, the farm gate price was US$ 18.00 to 25.50 per kg of dried cardamom. 

Traditionally Cardamom used to be cultivated in registered Cardamom orchards only.  In recent years farmers are also growing Cardamom in dry lands where food crops used to be grown.  The production is increasing primarily due to decline in the incidence of diseases naturally.

With the improvement in drying Cardamom in traditional driers locally called Bhatti the amount of fuel wood required for drying has been minimised and the quality has improved. 

The important aspect of Large Cardamom is its ability to grow on steep slopes and gullies where other crops cannot be grown successfully.  The dried Cardamom can be stored for a long time and it is easily portable.  No purchased inputs or chemicals are necessarily required or used and hence Cardamom of Bhutan is Naturally Organic Product. 

Since Cardamom is shade loving plant, farmers plant and maintain adequate shading trees in their plantations, which also provide sustained supply of fuel wood for drying.  Thus it has positive impact on environment. 

With regards to cultivation practices of Large the Cardamom in Bhutan, there is more to learn from farmers than to prescribe technical prescriptions based on proven facts available in scientific literatures. 

The Large Cardamom of Bhutan is known for its high natural qualities containing 2-3% essential oil which is its most desired flavouring property and has other properties like carminative, stomachic, diuretic, cardiac stimulant and antiemetic. 

GROWING Large CARDAMOM

Altitude

Large Cardamom can be cultivated from about 900 to 2000 m asl where severe frost do not occur and soils remain moist throughout the year. 

Soil

The ideal soil is acidic sandy loam soil and the soil depth should be 25 cm or more. 

The pH value of the soil should be about 5.0 to 6.5, which means acidic soil. 

The soil should have high organic carbon i.e. more than 3.5% organic carbon.  On an average the soils should have high in available nitrogen and medium in available phosphorus and potassium. 

Water logged conditions are not suitable.  This condition is naturally fulfilled as water logged areas is less on the slopping terrain where Large Cardamom is grown. 

Shade

The Large Cardamom is a shade loving plant.  It grows best in defused light under shade because direct sunlight is harmful to the plant. 

In summer months at least 50% of the full day sunlight must be intercepted.  The day light intensity required for optimum growth of Large Cardamom is about 5,000 to 20,000 lux. 

Shady trees must be grown to protect the Large Cardamom plants from direct sunlight in summer and from frost in winter.  In a newly established plantation distance between the shading trees should be about 5x5 meters and in a fully established plantation, depending upon the canopy size of individual species and their growth, the distance could be about 10x10 meters.

Rainfall

A good crop of Cardamom requires about 3000 to 3500 mm rainfall per annum.  To protect the plants from drought stress during dry months the plants should be mulched with dry leaves and trash accumulated from weeding of the orchard.

Land topography

Cardamom can be grown on any slope on which inter-culture operations can be done conveniently.  At lower altitudes, the South facing slopes are less favourable while at higher altitudes above 1200 m asl the importance of aspects of the slope is less. 

VARIETIES

The prominent varieties are altitude specific.  Therefore, while planting Large Cardamom the following guideline must be followed:

Altitudes (m asl)	Best Suited Varieties
900-1200	Golsey, Sawney
1200-1600	Rato-Golsey, Seto-golsey, Ramla, and Sawney,
Above 1600	Madhusey, Ramsey, Ramla and Bharlangay

Many wild relatives of Amomum subulatum like Amomum aromaticam are native to Bhutan, which offer opportunity for developing better varieties.

Golsey

Within Golsey, there are Seto Golsey, Rato (pink) Golsey and Dzongu-Golsey. 

Of the three, Dzongu-Golsey is specific to lower altitudes below 1200 m asl. 

Seto-Golsey is medium yielding variety and Rato-Golsey is a high yielding variety with less specificity to altitude. 

Golsey varieties are tolerant to diseases Tshirkay and Foorkay.

Sawney

Sawney is adaptable to different altitudes but its yield potential is lower than other varieties.  It has certain degree of tolerance to Tshirkay and Foorkay diseases.

Ramsey

Ramsey is suited to altitudes above 1600 m asl.  This variety is susceptible to Tshirkay and Foorkay diseases. 

Bharlangay

Bharlangay can be grown from 900 to 2000 ma asl.  Its yield increases with increasing altitude and the highest yield is above 1600 m asl.  However it is susceptible to Tshirkay and Foorkay diseases. 

Ramla and Madhusey varieties are suited to high altitudes.  The certified planting materials are only available in Sikkim in India and the reliable source of certified planting materials of Large Cardamom are:

►   Pangthang and Kabi Farms, Gangtok, Sikkim.

Besides conventional varieties these farms particularly the Pangthang Farm has evolved a number of promising clones like SBLC-5, SBLC-48, SBLC-49 and SBLC-50 through tissue culture technique. 

To import planting materials from Sikkim farmers are required to obtain Import Permit for Bhutan Agriculture and Food Regulatory Authority (BAFRA) and the plants should be brought along with valid phytosanitary certificate. 

PLANTING MATERIALS

Planting material can be produced from seeds or from slips cut from elite clumps. 

It is convenient to produce planting materials by cutting slips from healthy orchards not infested by diseases.  The slips with 2-3 leaves having folded young leaf upright at the growing point is of appropriate size for planting.  The rhizom at the base of the slips should be plump with a good number of roots. 

However, seedlings raised from seeds are free from virus diseases.  Disease free planting materials can be produced from seed harvested from elite clumps.

In Large Cardamom the yield per plant depends upon clump growth, plant height, number of spikes per tiller, number of productive tillers per clump, number of capsules per spike and size of the capsules.  Considering these criteria the elite clumps should be selected. 

The process involves the following steps:

Step-1:  Harvest the spikes from the elite clumps.  Separate the capsules and let it cure for 3-5 days.

Step-2:  Remove the seeds and wash with ash and fine sand; clean it and let it air dry in a dark room for 4-5 days only.  Do not keep of let it dry for more than 5 days. 

Step-3:  Apply good compost and fine sand at the rate of 10 kg each per square meter area.   Mix the soil, sand and compost thoroughly and raise the nursery beds of 15 cm height and 1.5 meter width. 

Step-4:  Before sowing treat the seeds with fungicide like Carbendazim 50 WP at the rate of 1-2 gm per kilogram seeds.  Sow the seeds in line 15 cm apart and maintain 2-3 cm distance between seeds. 

Cover the seeds with a soil layer of about 2-3 cm thick and cover the nursery bed with straw (about 2-3 cm thick). 

Watering should be done every day for a month after sowing, and in every two days in the second month.  From the third months onwards, watering is necessary twice a week until germination. 

The variety Golsey will germinate in about three months with a germination percentage of about 30-35 percent and the variety Ramsey will germinate in about 5-6 months with germination percentage of about 20-25 percent. 

Step-5:  After germination when the plants are about 15 cm tall in the second year, the saplings should be transplanted to second nursery at a distance of 30-40 cm apart. 

In the third year the sapling will be ready for transplanting in the months June-July, which is the appropriate time of planting Large Cardamom. 

The saplings ready for transplanting should have a height of about one meter with a number of young tillers. 

PLANTING

Initially planting should be done at a distance of 1.5 x 1.5 meters, which may later be spaced at 3 x 3 meters, depending upon the growth and size of the clumps. 

The planting pit size should be of 40 x 40 cm and it should be at least 30 cm deep.  The pits should be filled with the mixture of compost and top soils.  In each pit apply 5-10 kg compost. 

The appropriate time of planting is June, at the beginning of monsoon season.  It can also be planted in July but not later than July as the survival rate of plants goes down if planted in August. 

The number of seedlings per unit area depends upon the type of terrain and density of shady trees.  On an average about 2500 plants/ slips are required for one acre area. 

In an established plantation, farmers are advised to look for elite clumps from which the slips should be taken out for further plantation and gap filling. 

MANAGEMENT

In managing Large Cardamom orchard, four things are of utmost importance:

1.   Canopy cover management,

2.   Insect pests and diseases management,

3.   Inter-culture operations, and

4.   Protection from cattle grazing.

Canopy cover management

Farmers should consistently raise a nursery of shady tree and plant in spots where the canopy cover is opening up and direct sun light is falling on the ground.  Tree species that may be planted for shade, fuel wood for drying and other purposes could be:

Altitudes (m asl)	Shade Trees
	Botanical Name	Local Name
900-2000	Alnus nepalensis	Gama shing (Dz), Gotshanang shing (Sh), Utish (L),
900-1200	Schima wallichi	Puyam (Dz), Zala shing (Sh), Chilaune (L),
900-1200	Machilus odoratissima	Kaulo (L),
900-1500	Macaranga denticulate	Malato (L),
900-1500	Sapindus detergens	Nakapani (Dz), Kili shing (Sh), Ritha (L),
900-1600	Choerospondias axillaris	Lapsi (L),
900-1600	Boehmeria regulusa	Dongtshong shing (Sh), Dar (L),
1200-1600	Morus macroura	Tshondo shing (Dz), Shongden shing (Sh), Kimbu (L),
1200-2000	Myrica nagi Thunb	Kaphal (L),
1400-2000	Saurauvia nepalensis	Mongdormn shing (Sh), Gogun (L),
1400-2000	Castanopsis hystrix	Tsho shing (Sh), Patlay.Katus (L),
1400-2000	Nyssa javanica	Zala shing (Sh), Lekh Chilaune (L),
1500-200	Nindera neesiana	Singsi Shing (Sh)

Dz=Dzongkha, S S=Sartshop,  L=Lhostham

Besides, depending upon the local knowledge and the species growing in the locality farmer may choose to suit their best interest.

Insect pests

Several pests infest or damage Large cardamom, however heavy losses do not occur.  Among all, a vertebrate pest locally called ‘Kala’ does most damage as it eats ripened capsules.  Farmers should find and destroy its living places within the plantation and in the nearby areas to minimize the damage. 

In Large Cardamom orchards, there prevails micro-ecosystem where there exist a balance between pests and predators.  The insect pests in Large Cardamom orchard is best managed by managing the balance between pests and predators. 

Diseases

Among diseases, two viral diseases namely the Tshirkay and Foorkay are the major diseases of Large Cardamom. 

Effective direct control measure for these diseases is not there. 

To a certain degree the problem could be mitigated through field sanitation and removing infected plants at a regular interval. 

Whenever the symptoms of these two diseases are noticed, the infected plants should be removed and either burned or buried. 

In the infested area it is safer to use seed sapling instead of slips as planting material. 

The dynamics of aphid population responsible for transmitting the virus is not very well known. 

In infested areas farmers are advised to practice three things: (1) planting sapling from seed, (2) regular removal diseased plants based visual symptoms and (3) spray recommended organic pesticides only that help minimizing aphid population that spreads the disease. 

The symptoms of diseases:

Tshirkay

Symptoms are clearly visible in the young leaves.  Pale green stripes are seen on the leaves running from mid-rib to the margin of the leaves.  Later there will be a characteristic mosaic pattern. 

Foorkay

A Large number of pale yellow stunted sterile shoots come out.  The central spindles of the aerial shoots are damaged and thus emergence of leaves is hindered.

Besides Tshirkay and Foorkay, farmers may encounter rhizom rot problem. 

In case of rhizom rot, farm may drench the clumps with a solution of fungicides recommended for organic farming. 

Inter-culture operations

Manuring

Manuring should be done in the month of February.  In a well-managed orchard the compost made from the biomass collected during weeding and cleaning of the plantation should be enough.  It may be supplemented with farm yards manures and mulching with available mulch material. 

Irrigation

The Large Cardamom consistently needs a moist soil.  It needs irrigation particularly on the southern slopes in the months of November to March and often in the months of April if the rainfall is not adequate. 

The Large Cardamom flowers in the month of April and May and during these months if Large Cardamom plants suffer drought stress, the seed set will be very poor. 

In the kind of terrain on which Large Cardamom only the drip and sprinkler systems are appropriate. 

Farmers may adopt water harvesting and use drip or sprinklers to keep the soil moist uniformly across the plantation. 

Weeding

Weeding should be done at least twice a year.  First weeding should be done in May-June, i.e. at the beginning of the on-set of the monsoon and the second weeding should be done in September-October i.e. before harvesting time. 

The biomass cut or removed during weeding should be dumped in compost pits at convenient locations in the orchard. 

At harvesting time or soon after harvesting, farmers should remove tillers, which have produced fruits and tillers without fruits and dump in the compost pits. 

Farmers should follow guidelines provided for making plant nutrient enriched compost.

Pollination

The Large Cardamom is essentially a cross pollinated plant.  Due to the hetero-styllic nature of the flower they are often wrongly considered as self-fertile. 

For the Large Cardamom honey-bees and bumble bees are the chief pollinators and therefore farmers are advised to maintain honey bee colonies in their plantation to enhance the productivity of their orchard.

Protection from cattle grazing

The Cattle grazing in the Large Cardamom orchard is detrimental to the growth production particularly of the young plants.  The damage is caused by browsing and trampling on the young plants.  Also the germination and growth of naturally growing tree species are hindered. 

Farmers should plant adequate fodder trees in the orchards to meet the fodder requirement of the cattle rather than letting cattle to graze in the orchard. 

INTER CROPPING

Two economic species can be intercropped in the ecosystem in which Large Cardamom is grown. 

At lower altitudes from 900 to 1500 m asl, Pipla (Piper longum), the climber type Pipla can be grown by allowing the plants to climb on the shading trees. 

At higher altitudes from 1500 to 2000 m asl, farmers can intercrop Chirata (Swertia chirata) with Large cardamom. 

Like Large Cardamom these species are shade loving species and they can share a similar habitat. 

Pipla

There are two distinct types of pipla, the climber type Pipla (Piper longum) and bush type Pipla (Piper nigrum).  The cultivation of bush type Pipla cannot be integrated as it takes the space of Large Cardamom. 

The climber type Pipla is of higher value than the bush Pipla, which naturally grows in the humid sub-tropical forest of Bhutan. 

The propagation of Pipla can be through cutting and the cultivation method is same as that of Black Pepper (Piper nigrum). 

Chirata

Chirata (Swertia chirata) is a high value medicinal plant.  The species of highest grade and economic importance can only be found around Serthi and Lauri geogs of Samdrup Jongkhar dzongkhag. 

Seeds can be obtained from the places where it naturally grows.  Chirata is biennial crop and therefore it flowers only in the second year when it can be harvested and marketed. 

PRODUCTION AND YIELD

In good soil with optimum tree cover, production starts from the third year of planting and reaches the maximum in the 7-8^th years and continues up to about 20 years. 

After 20 years the production of the clumps declines and by 25 years the old clumps should be removed and replanting of young sapling preferably raised from seeds should be done.  Therefore, farmers should keep record of the year of establishment and productivity of the plantation and carry out replanting every 25 years. 

There is very little information on the yield of the Large Cardamom.  The anecdotal information on yield ranges between 100 to 600 kg per acre.  A good orchard may yield about 400-500 kg dry Cardamom per acre. 

Kar i basappa (1992) reported the yield of some varieties at different altitudes:

Yield per culm (gm)	Altitude (m asl)	Varieties
		Ramsey	Sawney	Rato Golsey	Seto Golsey	Dzongu Golsey	Ramla	Madhusey
	1325	772	630	1182	801	542	961	668
	1925	978	643	1144	920	76	919	1114

From this table some assessment on yield potentials may be derived.

DRYING

Large Cardamom is harvested in September at lower altitudes and in November in higher altitudes. 

About 2.6 tonnes firewood would be needed for drying Cardamom harvested from one hectare.  But in well-managed Large Cardamom orchards about 3.2 tonnes of firewood can be harvested annually through loping and thinning of shade tree (Masahiro Kawamura 2000). 

Drying in Bhatti

Large Cardamom capsules must be dried soon after harvesting, from the original moisture contents of 70-80% to less than 10%. 

Farmers in Bhutan still continue to dry Cardamom in the traditional dryer called bhatti, which takes 30 to 50 hours to dry one batch of cardamom. 

The thermal efficiency of the bhatti is only 5-15% due to which there is a huge loss of fuel wood.  Also, the fire in the bhatti is difficult to control and it often leads to localised charring of the capsules and thereby reducing the Cardamom’s volatile aromatic oil content and thus its culinary value. 

The smoke passing through also taints the Large Cardamoms’ flavour as well as turns them black from their natural red colour. 

Drying in gasifier-based drier

The Indo-Swiss Project Sikkim (ISPS) has developed through Tata Energy Research Institute (TERI), a simple updraft wood gasifier system for drying Cardamom.  This system can be made in local workshops and fitted to existing bhatti. 

The gasifier-based drier is beneficial in two ways:

►   First, it burns the fuel wood more efficiently and there will be 60% saving of fuel wood, and

►   Secondly, it improves the quality of dried Cardamom capsules by retaining its natural colour and 35% more essential oils, and by avoiding the burnt smell. 

The traditional Bhatti consumes up to 2.3 kg fuel wood for drying one kg of fresh Cardamom while the gasifier-based drier consistently dries one kg fresh Cardamom with 0.5 to 0.6 kg fuel wood. 

Reference

Pradhan P M (1999), RNR Technical Recommendations (Horticulture), RNR Research Centre, Khangma, June 2, 1999

Web Reference

►   CardamomDevelopment Centre (CDC), Ilam

►   Weeding, mulching, harvesting, Large cardamom, Sikkim

►   ICRI spots high-yielding Large Cardamomclones

►   Large Cardamomdiseases, sawney, Sikkim

►   Saurabh Gupta and Syed Taha Owais: IT potential in agriculture-A GIS implementation in evaluating Cardamompotential in Sikkim Himalayas

►   Sanjay Mande (TERI): India-Putting the colour back into cardamom

►   Mande P S, Kumar A, and Kishore V V N (1999), A study of Large Cardamomchambers in Sikkim, Biomass and Bioenergy 16: 463-473

►   Masahiro Kawamura, 2000, Large cardamom