SWEET POTATO

Propagation and planting

Season

Rainfed crop: June-July, September-October

Irrigated crops: October-November (for uplands) and January-February (for low lands)

Varieties

Improved varieties: H-41, H-42, Sree Nandini, Sree Vardhini, Sree Retna, Sree Bhadra, Kanjanghad, Sree Arun, Sree Varun

Sree Arun: A high yielding, early maturing sweet potato with pink skin and cream flesh developed at the Central Tuber Crops Research Institute (CTCRI), Sreekariyam. It is suited to the upland and lowland conditions and it can be grown all through Kerala. Average yield is 20-28 t/ha.

Sree Kanaka:  Short duration sweet potato with cream coloured skin and dark orange coloured flesh developed at the CTCRI. Average yield is 10-15 t/ha.

Sree Varun: A high yielding, early maturing variety with cream skin released from CTCRI. Average yield is 20-28 t/ha in 90-100 days.

Local varieties: Badrakali Chuvala, Kottayam Chuvala, Chinavella, Chakaravalli, Anakomban

Preparation of land

Work the soil to a fine tilth by ploughing or digging to a depth of 15-25 cm. Make ridges 25-35 cm high, 60 cm apart for planting vines.

Seeds and sowing

Sweet potato is propagated by means of vine cuttings. To obtain vine cutting, raise nurseries from selected tubers using the following method. Eighty kg of medium sized weevil free tubers (each of 125-150 g) are required for planting in the primary nursery area (100 m2 to plant one hectare).

Plant the tubers at a spacing of 30-45 cm on ridges formed at 60 cm apart and replant in secondary nursery of about 500 m2 area at a spacing of 25 cm. Apply urea 15 days after planting at 1.5 kg / 100 m2 in the primary nursery. To ensure better plant growth in the secondary nursery, 5 kg of urea has to be applied in two split doses on 15th and 30th day after planting. Vines obtained from the freshly harvested crop are also planted in similar nursery area to obtain sufficient planting material. Cuttings obtained from the apical and near apical portions of the vines are preferable for planting in the main field. Storing of cut sweet potato vines with intact leaves, in bundles covered with banana leaves (dipped in water) and kept under shade for two days prior to planting is recommended. Irrigate the nursery every alternate day during the first 10 days and once in 10 days, thereafter. Vines will be ready for planting on the 45th day.

In the main field, plant vine cutting of 20-25 cm length on ridges 60 cm apart and at a spacing of 15-20 cm between the vines. The cuttings can also be planted on mounds taken at a spacing of 75 x 75 cm. On the top of each mound, 3-6 cuttings can be planted. Plant the vine cuttings with the middle portion buried deep in the soil and the two cut ends exposed to the surface. Ensure sufficient moisture in the soil for early establishment of the cutting. Provide adequate drainage and prevent water logging.

Last updated: 19-06-2008