Elephant foot yam is called (Ool) in Nepali with scientific name Arror phophallus campanulus blue. The rhizome of elephant foot yam is consumed as vegetable and in medicine. Cunsuming it as vegetable helps in treating stomach pain as well as patient of Piles use it as tonic. This crop helps in eliminating weakness in body, promotes eye health and is considered good for heart and diabetes patient. It is used during Chhath festival, rhizome as vegetable, pickle and stem as gundruk. It is cultivated as alternative of potato and colocasia. As this crop is resistant to pest and disease attack where at present potato and colocasia are severely affected by pest and diseases. So, it can be alternative to those crops.
Elephant foot yam consists of Oxalic acid which cause irritation in the throat during consumption. It is higher in local varieties than improved or hybrid varieties and it can be reduced by washing, cleaning and boiling.
Climate & Soil:
Foot yam is generally grown in tropical and sub-tropical climatic region where it requires warm humid and long rainfall duration for proper vegetative growth and development. For proper rhizome development, dry and cool climatic condition is necessary. Continuous rainfall and water logging area is not suitable for this crop.
This crop can be cultivated in any type of soil but sandy loam soil with irrigation facility is considered best suited for this crop. In village areas of Nepal, currently this crop is being grown around house and land where fertility is very low. Nowadays, commercial cultivation of elephant foot yam in fertile land also has started.
Seed preparation & planting:
The rhizome of elephant foot yam is cut into pieces and planted as seed for propagation. The suitable size of each cut is around minimum of 500 grams to 1 kg at highest for better germination. For conserving moisture in cut piece, it is dipped in cow dung slurry before planting.
Plantation at areas where irrigation facility is available, it is plant during first to second week of Chaitra and places where no irrigation is present, planting is carried out during second and third week of Jestha.
Field preparation, Spacing & Pit digging:
Plough the field for 2-3 times making weed and crop debris free and soil free of clods before planting. Similarly, spacing for this crop is 1m between line to line or row to row and 1 m between plant to plant i.e. 1m * 1m (RR * PP). Also, it can be planted at spacing of 120 cm * 60 cm (line to line * plant to plant).
After keeping the required spacing between lines and plant to plant, pits are dug 15-20 days before planting of rhizome. Pit of size, 18 inches long, 18 inches wide and 18 inches deep are dug and manure is incorporated with soil before mixing and filling the pit. Soil should be placed a little above the surface of ground.
Manuring & Fertilization:
Well decomposed FYM @ 25 tons along with 55 kg urea, 88 kg DAP and 133 kg potash per hector is recommended and applied in elephant foot yam. Application of 2-2.5 kg FYM, 5 grams Urea, 10 grams DAP and 15 grams potash is recommended to apply per pit which gives optimum production result.
Irrigation, Weeding & Mulching:
The crop grown during the rainy season does not require irrigation however, crop planted during Chaitra will require irrigation according to the moisture status in the soil and growth stage of crop.
Since, this crop is grown in the rainy season weeding is mandatory for 3-4 times to keep it free from weed attack and yield loss. Generally, 2 weeding is done along with earthing up at the second time.
After completing plantation of elephant foot yam, either hay, sugarcane straw or grass is used to provide mulching to this crop in order to maintain moisture in the soil and to avoid weed growth at random way.
Harvesting & Storage:
This crop is generally harvested at the end of kartik month. However, as fresh vegetable it is consumed from Ashad-shrawn month in Nepal.
An average of 35-40 tons of elephant foot yam per hector is grown in Nepal.
Normal storage condition of this crop can keep it well for 3 to 6 months. Dry climatic condition will lead weight loss and wet & humid climatic condition will cause rhizome rot if stored for long duration.
Seed Multiplication production:
Using small rhizome as planting material cost in planting seed will become less. So, for seed yam production, high density planting is done with spacing of 50 cm * 50 cm (RR * PP). Normally, seed rhizome planted in 1 kattha area will produce seed enough for 1 bigha area of land.
Per kattha land:
- Total elephant foot yam production: 1500 kg
- Selling price: Rs. 10/kg
- Total Income: Rs. 15000
- Cost of production: Rs. 3500
- Net profit: 11,500