Elephant foot yam
Botanical Name – Amorphophallus campanultus Blume Family- Araceae
Varieties
Gajendra, Sree Padma
Climate and Soil
Soil –
Rich red-loamy soil with a pH range of 5.5-7.0 is preferred.
Climate –
It is a tropical and subtropical crop. It thrives well with a mean annual temperature of 30-350C. It requires well distributed rainfall of 1000-1500 mm spread over a period of 6-8 months, with humid and warm weather during vegetative phase and with cool and dry weather during the corm development period.
Season and Planting
It undergoes a dormancy period of 45 to 60 days. Traditionally farmers take
advantage of the dormancy period by planting during February-March so that the setts would
sprout with the pre-monsoon showers. April – May is the planting season.
The tuber is cut into 750-1000g small bits in such a way that each bit has atleast a
small portion of the ring around each bud. Whole corms of 500 g size can also be used as a
planting material. Use of cormels and minisett transplants of 100 g size as planting material
at a closer spacing of 45 x 30 cm is also suggested. There are also projections with tender
buds called ―Arumbu‖. These are removed before planting as they do not give vigorous
growth.
An ordinary sized yam gives about 6 to 8 bits for planting. The cut pieces are dipped
in cow dung solution to prevent evaporation of moisture from cut surface. In some places,
the small round daughter corms are also planted. The cut pieces are planted in beds at 45
cm x 90 cm spacing or pit of 60 x 60 x 45 cm size is dug and planted. The pit should be filled
with top soil and farm yard manure (2kg/pit) prior to planting. The pieces are planted in such
a way that the sprouting region (the ring) is kept above the soil. About 3500 kg of corms will
be required to plant one hectare. Sprouting takes place in about a mont
Preparation of Field
The land is brought to fine tilth and beds of convenient size are formed.
Intercropping
Vegetable cowpea var. CO 2 is recommended as suitable intercrop in elephant foot
yam. It can be intercropped profitably in coconut, arecanut, rubber, banana and robusta
coffee plantations at a spacing of 90 x 90 cm. Half quantity of FYM (12.5 t/ha) and one third
of NPK (27:20:33) will be sufficient for the intercrop
Irrigation
It is mostly raised as a rainfed crop. However, irrigation is required when monsoon
fails, where it is grown on a large scale. Water stagnation is harmful to the crop. Wherever
irrigation facility is available, irrigation can be given once a week.
Mulching
Mulching immediately after planting not only conserves soil moisture and regulates
soil temperature but also suppresses weed growth.
Application of Fertilizers
Apply 25 tonnes of FYM/ha during last ploughing. The recommended dose of
NPK/ha is 80:60:100 kg. Apply 40:60:50 kg NPK/ha at 45 days after planting along with
weeding and intercultural operations. Top dress with 40:50 N and K one month later along
with shallow intercultural operations.
After Cultivation
Weeding and earthing up as and when necessary.
1) Collar rot-
The disease is caused by a soil borne fungus Schlerotium rolfsii. Water logging, poor drainage and mechanical injury at collar region favour the disease incidence. Brownish lesions first occur on collar regions, which spreads to the entire pseudostem and cause complete yellowing of the plant. In severe case, the plant collapses leading to complete crop loss.
Use disease free planting material, remove infected plant materials, improve drainage conditions, incorporate organic amendments like neem cake, drench the soil with carbendazim (1g/l of water). or apply biocontrol agents like Trichoderma harzianum @ 2.5 kg/ha mixed with 50 kg of FYM.
Harvesting
It becomes ready to harvest in about 8-9 months after planting. The crop attains
maturity when total senescence takes place.
Yield
30 – 35 t/ha in 240 days.
For seed purpose, the yams can be left in the field itself till planting the next crop or the lifted yams can be stored in sand or paddy straw.
