Introduction
In Andhra Pradesh, it is cultivated in an area of 697 hectares producing 13,940 tons mainly in Visakhapatnam, East Godavari, Guntur, Nellore, and Telangana areas. It is mainly cultivated for the vegetable purpose. In addition, it is also utilized as animal feed and also for the preparation of starch and alcohol.
Scientific name-Ipomoea batatas.
Climate required for growing Sweet potato
It is a tropical crop and requires plenty of the sunshine and moderate rainfall with cool nights and days for the growth.
Season for Sweet potato
The main season for sweet potato is Rabi (October-November) but can also be grown in Kharif (June-July) and summer (February-March).
Soil requirement
Well, drained light loams are best suited. Rich soils, heavily manured soils tend to produce much vegetation at the expenses of tuber formation. A soil pH of 5.6-6.6 is preferred.
Sweet potato varieties
1.Samrat (S-30)
The tubers are white with pink streaks and can be cultivated in all the three seasons of the year with a yield potential of 15-20 tons/ha in a period of 120-135 days.
2.Kiran
This variety released by APAU. Tubers are orange in color with grayish streaks High yielder of Medium duration (120 days). Can be cultivated round the year, moderately tolerant to sweet potato weevil and yields 18-20 tons/ha.
3. S30/21
White skinned short duration type can be cultivated throughout the year, with a yield potential of 15-17 tons/ha.
Propagation
Semi matured vine cuttings are utilized for commercial propagation. Small tubers can also be used for raising nursery.
Preparatory Cultivation
Plough the land 4-5 times to get fine tilth. If ploughed deep, there is a tendency for the roots to grow deeper. Therefore deep ploughing is avoided, plots of convenient size are being formed and separated by irrigation channels.
Seeds and Sowing time for Sweet Potato cultivation
30-40 cm long cuttings preferably from the top with 5-6 leaves intact is selected. The cuttings are planted vertically by pushing at least 2-3 nodes in the soil at a distance of 60 x 20 cm in the flat beds. A nursery of 20-25 cents is sufficient to plant one ha.
Fertilizers for Sweet Potatoes
Apply 10-15 tons of FYM/ha. Incorporate 60kg of P2O5 in the soil as basal dose. 60 kg/ha each of N and K2O is applied in two split doses at 30th and 60th day after planting.
Intercultivation
Two or three weddings and light hoeing may be given at 15-20 days after planting. Occasional lifting of vines and gently turning them is necessary to break and disconnect the roots formed at their nodes 45 and 75 days after planting.
Irrigation of SweetPotato
Irrigate at a weekly interval in the early growth period and increase the frequency at the time of tuber formation (60 to 90 days after planting). Late on irrigation at 10-15 days interval should be given.
Sweet potato Harvesting and Post harvesting Technology
The crop will be ready for harvest in about 4 to 4 ½ months after planting as indicated by yellowing of leaves. Do not keep the mature tuber in the soil longer than necessary as they would be severely affected by weevils. Cut the vines and lift the tuber with crowbar or pickaxe. In light soil, plough with country plough and collect the tubers. The tubers are cleaned and send to the market. The tubers can also be stored under the shade for 15-20 days without getting sprouts.
Plant Protection
Pests of Sweet Potato
1. Sweet Potato Weevil (Cylas formicarius)
Adult weevil makes puncturing on vines and tubers. The grubs bore and feed by making tunnels. Feeding and adult emergence holes can be seen on vines and tubers. In severe infestation, the collar region of the plants shows unusual thickening due to proliferation dn hypertrophy of tissues casing of a characteristic terpenoisd odour. Even the slightly damaged tubers are unsuitable for consumption due to bitterness. Yield loss may go up to 100% in severe cases. On an average, 20-55% tuber loss occurs.
Control
- Remove previous sweet potato crop residues and alternate host i.e., Ipomoea sp. and destroy them.
- Use pest-free planting materials.
- Dip the planting material in Fenthion 100 EC or Fenitrothion 50 EC.
- Rake up the soil and earth up at 50 days after planting.
- Drench the soil with Fenthion 100 EC at 2 ml/l. Spray any one of the insecticides, if needed
- Harvest the crop immediately after maturity and destroy the crop residues.
Diseases of Sweet Potato
1. Soft rot
Soft rot can be controlled by spot drenching with Carbendazim 1 g/lit.
Sweet potato Yield
About 20-25 t/ha of tubers in 110 – 120 days can be obtained.
Source-
- Dr. Y. S. R. Horticulture University, Andhra Pradesh.
- Tamil Nadu Agriculture University.
