Turmeric

Morphology

Morphology Growth Taxonomy

Morphology

  • Turmeric is an erect perennial herb, but is grown as an annual.

Rhizome

  • The plant possesses an underground stem or rhizome, which is thick and rounded, with short blunt fingers.
  • It also emits slender branches, which develop into thickened tuberous portions.
  • The outside of the rhizome, which is usually rather closely ringed, is brown and scaly.
  • The inside is of a bright orange colour, and possesses a very distinct odour and taste. The rhizome is the portion used as a spice, under the name of turmeric.
  • The main part of rhizome is known as long turmeric. The tuberous portions are known as round turmeric.

Shoot

  • The leafy shoots rarely exceed 1 m in height and are erect, bearing 6-10 leaves with the leaf sheaths forming a pseudostem. The thin petiole is rather abruptly broadened to the sheath.
  • Ligule is a small lobe, about 1 mm long.
  • Lamina is lanceolate, acuminate and thin, dark green above and pale green beneath with pellucid dots. It is usually upto 30 cm long and 7-8 cm wide, and is rarely over 50 cm long.
  • The leaf sheath near the ligule has ciliate margins.

Leaves

  • The leaves are borne in a tuft, and are about 60 cm tall, but frequently shorter. They are thin, rather flaccid, and light green in colour, lanceolate acuminate, with rather a long leaf stalk.
  • There are usually six to ten to a tuft and several tufts to a rhizome.

Inflorescence

  • Cylindrical spike, 10-15 cm long and 5-7 cm wide which is terminal on the leaf shoot with the scope partly enclosed by the leaf sheaths.
  • The spikes are shorter than the leaves and supported by a stout peduncle. They consist of a great number of thin, greenish-white , ovate bracts, the upper most being usually pink and rather longer than the lower ones. The upper bract is sterile and white or white streaked with green, pink-tipped in some cultivars.

Flowers

  • In each bract, there are two flowers opening one at a time
  • Flowers are thin-textured and fugacious, white or yellowish white, with a broad yellow band down the centre of the lip.
  • The calyx is short, unequally toothed and split nearly half-way down one side. The corolla is tubular at the base with the upper half cup-shaped with three unequal lobes inserted on the edge or the cup lip; it is whitish, thin and translucent with the dorsal lobe hooded.
  • There are two lateral staminoids, elliptic-oblong, creamy white in colour, and with the inner edges folded under the hood of the dorsal petal. The lip or labellum is obovate with a broad thickened yellow band down the centre and thinner creamy white side-lobes upcurved and overlapping the staminoids.
  • The filament of the stamen is short and broad, united to a versatile anther about the middle of the parallel pollen sacs.
  • The ovary is inferior and trilocular with a slender style passing between the another lobes and held by them.

Fruits

  • Fruits are seldom, if ever produced (the fruit does not seem to be known)

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Growth

There are five growth phases for turmeric crop

Phase
Duration (months)
Days from planting
Germination 1 0-30
Moderate vegetative growth 1 1/2 31-75
Active vegetative growth 2 1/2 76-150
Slow vegetative growth 2 151-210
Approaching senescence 2 211-270

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Taxonomy

Turmeric / Turmerico, Curcuma domestica Valeton
(Syn : C. longa L. C. rotundaL. Amonum curcuma Jacq.)
Family: Zingiberaceae Order: Scitamineae

  • Turmeric is the dried rhizome of C. domestica, a herbaceous perennial belonging to the family Zingiberaceae, which comprises 40 genera and 400 tropical species in the old world.
  • The name Zingiber has originated from Sanskrit word "Singabera" which means horn shaped.
  • Genus Curcuma (Arabic name) has 40-50 species, situated in tropical Asia. Members of Curcuma are strong erect herbs with rhizome bearing habit. Leaves are large, lanceolate/oblong with short or no stamens. Flower is a dense spike ending with a tuft of large coloured bracts with two or more flowers arising from each bract, Calyx is a short cylindrical toothed tube and corolla comprises of broad segments.

Curcuma domestica

  • Pseudostem is tall, robust with oblong/elliptic leaves narrowed at the base.
  • Plant height at 67-83 cm in long duration, 67 - 69 cm in short duration, 8-10 leaves for long and 7-8 for short duration types.
  • The leaf length may range from 30-45 cm and breadth 14-16 cm with petiole equalling the blade.
  • Spike length ranges from 10-18 cm with a diameter of 5 cm.
  • Flowers are pale yellow in colour equalling the bracts.
  • Starch root tubers are not produced at the end of the fibrous roots.
  • Flowering is stray and the species is a sterile triploid (3n = 63) and does not set viable seeds.
  • Rhizomes are bigger in size with a stout mother rhizome, with branching primary and secondary fingers exhibiting yellow to bright orange yellow core.
  • Rhizomes are rich in curcumin but moderate in volatile oil.
  • Most of the high yielding cultivars fall in this group and have a prolonged maturation period of 8-9 months.

Curcuma aromatica

  • Pseudostem is slender, short with elliptic/oblong leaves.
  • Flowers are pale yellow
  • Plants are tetraploids (4n = 84) and fertile
  • Flowering is common in this species and set viable seeds which give rise to weak seedlings.
  • Plants produce peculiar root tubers at the end of the fibrous roots.
  • Rhizomes possess pleasant aroma and hence this turmeric is called 'Kasturi' in Andhra Pradesh and in a few other states in India and used as an aromatic spice besides colouring agent in culinary food preservations.
  • Rhizomes are very slender, rich in volatile oil responsible for the unique aroma but moderate in curcumin content.
  • Rhizome production is much poorer compared to C. domestica types.
  • Cultivars of this species mature early, within 6-7 months.

Species

  • Nearly 30 species of Curcuma are known to exist while only one species C.domestica contributes to the commercial production of turmeric to an extent of 90 per cent.
  • Other species viz. C. aromatica, C. amada and C. angustifolia are cultivated to a limited extent in southern parts of India.

The important species of curcuma are

Cultivated species

  • C. domestica
  • C. aromatica

Semi wild species

  • C. amada
  • C. angustifolia
  • C. cassia

Wild species

  • C. decipiens
  • C. zedoaria
  • C. neilgherrensis
  • C. petiolata
  • C. lorgengii
  • C. aurantiaea
  • C. xanthorrhiza
  • C. cordata
  • C. albiflora
  • C. australasica
  • C. roscoedna
  • C. rubescens

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Tamilnadu

Turmeric

Turmeric Management