CHEMBU ( ചേമ്പ് )

In Malayalam tubers of Colocasia and Xanthosoma are commonly called as Chembu. It is  comes under Family  Aracacea.

Three major tuber crops comes  under Aracacea are
1. Colocasia esculanta 
2. Xanthosoma sagitifolium.
3. Allocacia  spp.
 English:
The common names of Colocasia esculanta are Taro, Eddoe, Old Cocoyam, Malanga.
The common names of Xanthosoma sagitifolium are Tannia,Yautia, New Cocoyam.

Comparison of Colocasia  with Xanthosoma
Colacasia is one of the oldest crops in India. Xanthosoma originated in Tropical south Amerca and introduced to India.
Colacasia is a gregarious herb cultivated for its edible tuber, stem and leaves whereas Xanthosoma spp. mainly cultivated for its edible tuber.
Colacasia is planted in fertile soil with high water retention capacity whereas Xanthosoma is planted in well drained soil. 
Xanthosoma is a partial shade loving plant.  
Colocasia leaves are more or less round and soft .The leaf tip always point downward.  Xanthosoma have a slightly arrow shaped, dark green coloured, thick, glossy leaf and the petiole attaches at the notched edge of the leaf.

Common features:
Colocasia and  Xanthosoma are fast growing, annual crop, grows up to 1.5 meters height. 
About 1 meter long petiole emerges from base. Leaf blade is up to 60cm length and 50 cm width. The under ground parts consists of one large central corm and a number of cormels called tubers. 
In fertile soil each side tuber may weigh about 200gm.

Food value:
Corm, petiole and leaves are edible.
It is used as a vegetable or as subsidiary food after roasting, baking or boiling. 
The leaves and petioles are cooked like any other green leafy vegetables.
Raw plant is slightly toxic due to the presence of calcium oxalate. These toxins can be removed by boiling. 

 Medicinal value:
Due to the high digestibility it is recommended for gastric patients and it is a good baby food.
It is a good source of carbohydrates, starches, proteins and vitamins.

Planting method:
It is mainly a rain fed crop.
Side tubers or the top portion of the mother corm is also used for planting.
As per the age old practice of Kerala, after collecting the side tubers, the top portion of the mother corm is stored for next years planting.
Before storing it has to be dip in diluted cow dug and dried in shade, 
The planting starts in the Malayalam month of “Kumbam” ( ie, February-March ) or just before the rainy season.( For rain fed crops)
(For irrigated crops – it can be planted throughout year.)
The land should be plough two or three times and bring to a fine tilth. Make ridges about 60 cm diameter and plant the corm at the centre. 
Cover the planted area with green or dry leaves. Mulching with green or or dry leaves is most important to improve germination,to control weeds and to retain soil moisture. It will keep the soil loose and fertile. 
In the month of July give sufficient fertilizer (cattle manure or compost) after hand weeding and cover with loose soil. For getting a good yield usually two earthing up are done 
Crop will ready for harvest after 8-9 month of planting.

Average yield is up to 12- 15 tones/Hactores.

LOCAL NAMES/ VARITIES OF CHEMBU ARE:
Kannan chembu,Thamara kannan, Velutha kannan, Chuttikannan, Injikannan, Aarattupuzha kannan.
 Karkadaka Chembu, Kolambi chembu, Cheru chembu
Seema chembu, Sambar chembu, Pal chembu, Marachembu, Kudachembu, Mutta chembu,
Vazhachembu, , Vellichembu, Kodachembu, Vettuchembu.
Chutti, Cheru chutti, Inji chutti,
Karim chembu, Neelachembu, Vettichembu, Chakka chembu.
Purakkadan,  Pavachembu, Marakambin chembu.

OTHER NAMES:
Arvi(Hindi),
Sembu(Tamil),
Chamadupa(Telugu),
Kesavedantu(Kannada).