Kou-kha : A wetland tuber cash crop of Manipur

Dr N Irabanta Singh *

Kou-kha : Rhizome Festival at Thoubal in January 2018 :: Pix - Lamdamba Oinam

Introduction: Kou-kha/arrow head is botanically known as Sagittarie sagittifolia. It belongs to the family Alismataceae (Monocotyledonous).

Growing form: Monoecious, aquatic perennial, with wintering tubers);

Height: 20-80 cm (8-30 inches), stem 3 separate, white with a purple blotch at the base. Sepals -3, separate, shorter than petals-3, separate, white with a purple blotch at the base. In lower part of inflorencence, these are female flowers with pear shaped carpels.

Upper parts bear male flowers with numerous purple stamens. Central flowers have many stamens and some carpels.

Flowers borne in whorls of 3 in the inflorescence; Leaves - most leaves aerial, some floating, some submerged, long-stalked, blade-arrow head like basal lobes almost as large as apical part, floating leaves with more rounded blade, even oval with cordate base; margins entire. Submerged leaves strap-like; fruit-Achene, flowering time - July to August.

Habitat : On muddy bottom in shallow water of lakes rivers, ponds,etc.

Distribution: Europe from Ireland and Portugal to Finland and Bulgaria. It is also found in Australia, Vietnam, Caucases, etc.

Kou-kha is also grown widely in the valley areas of Manipur (India) particularly in wetlands and paddy field.

Edible parts: The local name kou-kha is the tuber part of the arrow head. It is about 15 cm in diameter and is best harvested in late summer as the leaves die down.

Nutritional Values: The tubers contain 7.74% of crude protein, 633 mg/100 g of potassium, 8.06 mg/100gm of Iron and 80% moisture.

Medicinal Values: Seven new ent-rosane diterpenoids and a new Labdane diterpene were purified (2006) from the Chinese medicinal plant (Sagittaria sagittifolia).

Four of these compounds (Sagittene A-D) exhibited antibacterial activity against Streptococcus mutans and Actinomyces naeslundii while another ( Sagittine E) was only active against A. naeslundii.

Recently, the same group identified 5 new diterpenoids from Sagittaria Pygmaea. None of these displayed activity against A. actinomycetemcomitans , while 4 of the others were active against A. vicous and 3 were active against S. mutans of which 18-B-D, b diacetoxyglucopyranosyl-ent-laur-16-ene was the most active.

Economics of Kou-kha: During December to end of February, Kou-kha tubers are sold @Rs.20 per tea glass at Khwairamband Bazaar. At the larger quantity, kou-kha is sold @150 per kg ( Annual spray empty cane). Large scale of Kou-kha is not seen at the local market. This might be because of big gap between supply and demand of Kou-kha in Manipur. More production is envisaged for improving socio-economic stakes of the rural poor of the Manipur state.

Discussion: The Kou-kha is regarded as one of the best Ethno-nutriacentical plant because it possesses various therapeutic properties in their biofunction parts such leaves, tubers, etc. pharmacologically the plant is also used as anti-microbial, anti-inflammatory, anti tumor, antiscorbutic, diuretic, antioxidant, immune modulatory, antidiorrhoreal, antiseptic, anthelmentic and antiviral activity.

Further, the leaves and tubers are reported for the presence of phytochemicals like Tanin, Saponins, flavonoids, phenol, steroids, Glycosides, Proyein, Aminoacids, starch, reducing sugars and alkaloids.

Conclusion: Steroids, Terpenoides, Tanin, Phenols, Saponins, Alkaloids, Glycosides, flavonoids, Protein, Amino acids, and starch are reported from the leaves and tubers of Kou-kha.