Large cardamom (Amomum subulatum Roxb.)

2016

Large cardamom or Nepal cardamom (Amomum subulatum Roxb.) is a spice cultivated in the sub-Himalayan region of north-eastern India, especially in Sikkim since time immemorial. In the past the aboriginal inhabitants of Sikkim, Lepchas, collected capsules of large cardamom from natural forest, but later on these forests passed into village ownership and the villagers started cultivation of large cardamom. The presence of wild species, locally known as churumpa, and the variability within the cultivated species supports the view of its origin in Sikkim (). Later the cultivation has spread to northern Uttar Pradesh, north-eastern States of India (Arunachal Pradesh, Mizorum and Manipur), Nepal and Bhutan. Sikkim is the largest producer of large cardamom; the annual production in India is about 3500–4000 mt of cured Large cardamom. The average productivity is 100–150 kg/ha, but in well-maintained plantations the productivity reaches 1000–2000 kg/ha. Nepal and Bhutan are the other two countries cultivating this crop with an annual production of about 1500 mt. This spice is used in Ayurvedic preparation in India as mentioned by Susruta in the sixth century BC and also known among Greeks and Romans as Amomum (Ridley, 1912). Large cardamom contains ca.1.98–2.67 per cent volatile oil and is mainly used in flavoring food products (). The seeds also possess certain medicinal peroperties, as carminative, stomachic, diuretic, cardiac stimulant, antiemetic and are a remedy for throat and respiratory troubles ()

The commodity is mainly sold in the domestic markets of northern India. Over the past few years large cardamom is also being exported, and in 1997–98, Rs.12.6 crores of foreign exchange was earned by exporting 1784 tonnes. Pakistan, Singapore, Hongkong, Malaysia, UK and Middle East countries are the major importers of this commodity.

Thabit and Habita

Amomum subulatum is a perennial herb that belongs to the family Zingiberaceae under order Scitaminae. The plant consists of subterranean rhizomes and several leafy aerial shoots/tillers (leafy shoot). Number of such rhizhomatous leafy shoots varies between 15–140 in a single plant (a clump). Height of leafy shoot ranges from 1.7 to 2.6 m depending on cultivar and possess 9–13 leaves in each tiller. Leaves are distichous, simple, linear and lanceolate, glabrous on both sides with a prominent mid rib. Inflorescence is a condensed spike on a short peduncle (). Flowers are bracteate, bisexual, zygomorphic, epigynous, and cuspinated. The yellowish perianth is differentiated into calyx, corolla and anther crest. Each spike contains about 10–15 fruits (capsules) and rarely up to 20–25 capsules, depending on cultivars. Flowering season begins early at lower altitude with peak flowering during March–April, whereas it starts at higher altitudes in May with a peak during June–July. Harvesting begins during August–September at lower altitudes and in October–December at higher altitudes ().

The fruit is a round or oval shaped capsule, trilocular with many seeds. Capsule wall is echinated, reddish brown to dark pink. Seeds are white when immature and become dark grey to black towards maturity. The capsules formed at the basal portion of spike are bigger and bolder than others ().

Large cardamom is grown in cold humid conditions under shade of trees at an altitude between 800–2000 m above mean sea level (amsl) with an average precipitation of 3000–3500 mm, spread over about 200 days and the temperature ranging between 6 °C in December–January to 30 °C in June–July (). Frost, hailstorm and snowfall are the major deleterious factors affecting Large cardamom (). The crop grows well in moist, but well drained loose soil. The depth of soil varies from a few centimeters to several meters depending upon the topography and soil formation. Soil is acidic and rich in organic matter ().

Cultivars of Large Cardamom

Plant Propagation of Large Cardamom

Large Cardamom: Plantation Management

Crop Improvement

Flowering and pollination

Large cardamom, is essentially cross-pollinated, insect pollination is the rule. The flower morphology is adapted for such a mode of pollination. Each spike consists of about 40–50 flowers, which open in the acropetal sequence over a period of about 15–25 days. Flower opening starts at early morning hours, i.e. 3–4 a.m., anthers dehisce almost simultaneously whereas stigma receptivity starts an hour later and lasts for 24 h. The stigma was found to be receptive even after 36 h from the time of flower opening during rain-free days ().

Bumble bees (Bombus sp.) are the main pollinators, though a variety of honeybees and other insects do pollinate the flowers (). Bumble bees are effective pollinators due to its compatible size with the flowers and is having brush-like hairy structures on its dorsal thorax which helps in carrying pollen mass and depositing it on stigmatic surface while entering the flowers. The highest foraging activity of bumble bees is seen during 6–7 a.m., but becomes slow or dull in rainy conditions.

Genetical studies

Studies on coefficient of variation was undertaken by Karibasappa et al. () in five varieties of large cardamom (Sawney, Pink Golsey, Ramsey, Ramnag and Madhusey) for mature tillers per clump, panicles per clump and capsule–panicle ratio. This study indicated high heritability coupled with high genetic advance for characters such as length of mature tiller, panicles per clump, panicle weight and capsule yield. The capsule yield was directly correlated with clump girth, panicle weight, panicle per clump, mature tillers and capsule–panicle ratio. Correlation studies () also indicated that mature seed index, total soluble sugars (TSS) of seed mucilage and 1000 seed weight were associated positively with oleoresin and negatively with cineol contents.

Clonal selection

Explorations for collection of germplasm of Large cardamom was carried out by Indian Cardamom Research Institute (ICRI), Regional Station, Gangtok at various tracts and a gene bank consisting of 180 accessions is established at Pangthang. Rao et al. () reported a promising selection of Barlanga cultivar from high altitudes, having desirable characters like high ratio of mature tillers to productive spikes (1:3.6) and capsules having very bold size (with 50–80 seeds per capsule). Based on a preliminary evaluation, four selections (SBLC-5, SBLC-42, SBLC-47 and SBLC-47A) having high yield potential have been identified by the ICRI, Regional station, Gangtok. They are multiplied in large numbers using micropropagation technique and distributed among the farmers for cultivation.

Large Cardamom: Insect Pest Management

Diseases of Large Cardamom

Large Cardamom: Harvesting and Post Harvest Technology

Properties and Uses

Large cardamom is used as an ingredient as well as a flavoring agent with masala and curry powders; in flavoring sweet dishes, cakes, and pastries; as a masticatory and for medicinal purposes. The seeds are used for chewing along with betel quid (betel leaf, areanut lime, with or without tobacco). In gulf countries large cardamom is used as a cheaper substitute for spicing tea in place of cardamom. In the Indian systems of medicines – Ayurveda and Unani, it is used as preventive as well as curative for throat troubles, congestion of lungs, inflammation of eyelids, digestive disorders and even in the treatment of pulmonary tuberculosis (). The seeds are fragrant adjuncts for other stimulants, bitters and purgatives. The seeds have a sharp and good taste and are tonic to heart and liver. The pericarp is reported to be good for alleviating headache and heals stomatites (). Decoction of the seeds is used as a gargle in afflictions of teeth and gums. With melon seeds they are used as a diuretic in cases of gravel of the kidneys. They promote elimination of bile and are useful in congestion of liver. They are also used in the treatment of gonorrhea. In large doses with quinine, they are used in neuralgia. The seed oil is applied to the eyes to allay inflammation.

The direct uses of large cardamom are in pickles, pulao, meat and vegetable dishes. It is also used in industrial sector for flavoring toothpastes, sweets, soft drinks, toffees, flavored milk and alcoholic drinks. The ripe fruits are eaten raw by people of Sikkim and Darjeeling and are considered a delicacy ().

Conclusion

Large cardamom is a crop of the north-eastern Himalayan tracts, the largest producer is the state of Sikkim in India. It is used extensively as a spice in South Asian countries, and as a substitute for true cardamom in the Middle East regions. It is also important in tribal and indigenous medicine.

Research inputs on this crop has been meager. Efforts are yet to be made in evolving superior genotypes combining high yield and quality. A search for aroma quality is essential to locate lines of superior flavor and quality composition. More important is the management of diseases and pests, especially developing resistant or tolerant lines against the two serious virus diseases – foorkey and chirke. The rich genetic diversity found in the centre of origin (Sikkim and adjoining areas) has to be screened for locating natural resistance against diseases and pests, and for locating superior genotypes. A search for types adaptable to lower elevation will be a boon to take the cultivation of this crop to the lower hills. A good tissue culture protocol for large cardamom is available and large scale multiplication of some of the elite lines will provide disease free superior planting material to the growers. Appropriate research back up is also needed to provide and popularize an efficient drying technology that will be suitable to the location and acceptable to small and medium growers.

 

Selections from the book: “Cardamom. The genus Elettaria”. Edited by P.N. Ravindran and K.J. Madhusoodanan. Series: “Medicinal and Aromatic Plants — Industrial Profiles”. 2002.