The botanical name of Sweet potato is Ipomoea batatas. This crop is mainly grown because of its sweet taste and starchy roots. The tubers are rich source of beta-carotene and are used as anti-oxidants. It is an herbaceous perennial vine having lobed or heart shaped leaves. Its tubers are edible, smooth skin, tapered and long. It has wide color range of tuber skin i.e. red, brown, white and purple which contains wide range of flesh i.e. yellow, orange, white and purple.

Sweet potato is good for heart. It helps in controlling blood sugar, also help in relieving stress.

In India about 2 lakh of land is under cultivation of sweet potatoes. Bihar, West Bengal, Uttar Pradesh and Orissa are the major growing states in India.

In Uttar Pradesh, near about 331 thousand hector area is under sweet potato cultivation and contribute about 27% in total production. Etah, badaur, Farookabad and Sultanpur are major sweet potato growing areas of UP.
 

It is grown in variety of soil types ranging from sandy to loamy soil, but it gives best result when grown under sandy loam soil having high fertility and good drainage system. Avoid cultivation of sweet potato in very light sandy and heavy clayey soil as it is not good for tuber development. It requires pH ranging from 5.8-6.7 is best for sweet potato cultivation.

Kiran: Ready to harvest in 110-120 days. Spreading variety with tubers having red color skin and orange flesh. Gives average yield of 8-10 tonnes/acre.

Rajendra Sakarkand 5: Ready to harvest in 105-120 days. Tubers with white color skin and flesh. Gives average yield of 9-12 tonnes/acre.

Rajendra Sakarkand 35: Ready to harvest in 105-120 days. Tubers with brown color skin and flesh. Gives average yield of 10-12 tonnes/acre.

Rajendra Sakarkand 47: Ready to harvest in 120-130 days. Tubers with red color skin and white flesh. Gives average yield of 10-12.8 tonnes/acre.

VL-Sankarkand 6: Late maturing variety, ready to harvest in 135-140 days. Purple color skin with light yellowish flesh.  Gives average yield of 8.0 tonnes/acre.

Samrat: Ready to harvest in 110-120 days. Tubers having light pink color with white flesh. Gives average yield of 8.0 tonnes/acre.

Shree Bhadra: Semi spreading variety having light pink tuber skin with creamy flesh. Ready to harvest in 90 days and average yield of 8.0 tonnes/acre.

Narendra shakarkand 9: Ready to harvest in 120days. Tubers with white skin and flesh. Gives average yield of 11 tonnes/acre.

Narendra Shakarkand 10: Mid-season variety, ready to harvest in 120 days. Tubers with red skin and white flesh. Gives average yield of 9 tonnes/acre.

Pusa Red: This variety has red color tubers which contains white flesh, medium sized tubers which is thick from the middle.

Pusa White: This variety has white color tuber and flesh, and is medium in size. This variety gives high yield.

Other state varieties:

Punjab Sweet Potato-21: The vines of this variety are medium long in length. It has broad shape and dark green color leaves, long and thick stem, 4.5 cm inter nodal length and has 9 cm petiole length. It contains deep red color tubers having white flesh which is 20 cm long and 4 cm wide. The variety gets mature within 145 days. The average weight of tuber is 75 gram. The tuber contains 35% of dry matter and 81mg/gram of starch. It gives an average yield of 75 Quintal/acre.

Varsha: It is recommended to grown in Maharashtra. It is suitable to grown in rainy season. It gives an average yield of 62.5 Quintal/acre.

Konkan Ashwini: This variety is developed to be cultivated in Maharashtra. It is short duration crop and gives high yield.

Sree Arun: It is an early maturing variety having pink color skin and cream color flesh. The variety is developed by Central Tuber Crop Research Institute (CTCRI), Sreekariyam. It gives an average yield of 83-116 Quintal/acre.

Sree Kanaka: The variety is developed by Central Tuber Crop Research Institute (CTCRI), Sreekariyam. It has cream color skin tuber which has dark orange color inner flesh. It gives an average yield of 41-62.5 Quintal/acre.

Sree Varun: The variety is developed by Central Tuber Crop Research Institute (CTCRI), Sreekariyam. It contains cream color skin of the tuber. It is an early maturing variety which gets mature within 90-100 days. It gives an average yield of 80-110 Quintal/acre.
Gautam: Ready to harvest in 105-110 days. Gives average yield of 12 tonnes/acre.

Sourin: Ready to harvest in 105-110 days. Gives average yield of 12 tonnes/acre. Red tubers with creamy flesh.

Kishan: Ready to harvest in 110-120days. Gives average yield of 12 tonnes/acre.

Improved varieties:

H-41, H-42, Co 3, Co CIP 1, Sree Vardhini, Sree Rethna, Sree Nandini, Kanjanghad, Gouri, Sankar.

For sweet potato plantation, the land should be well prepared. To bring the soil to the fine tilth, before sowing land must be ploughed 3-4 times at depth of 15-20 cm followed by planking. The field should be weed-free. For sowing, ridges and furrow or mounds or flat-bed method is used. In field having drainage problem, mounds are used for planting. Where as in area’s having soil erosion problem, ridges and furrows across slope are used for planting.

Time of sowing:
For kharif season, June-July is optimum time for vine transplantation. For low land areas, January to February whereas October- November is optimum time for transplantation.

Spacing:
Use row to row spacing of 60 cm and plant to plant spacing of 20-30 cm.

Method of sowing:
Transplanting of vine cutting in main field.

Mainly propagation is done by tubers or vine cuttings. In vine cutting method (commonly used), the tubers are planted on prepared nursery beds i.e. on ridges, at spacing of 20-30 cm with row spacing of 60 cm. Apply Urea @ 1.5 Kg/100 m², 15days after planting. Apply irrigation on alternate days for first 10 days. Then reduced frequency of irrigation. After 45 days, cut vines at length of 20-30 cm. Then these are planted in second nursery of 500 m² area.

Freshly harvested vines are planted on ridges having row spacing of 60 cm and plant spacing of 20 cm. Apply well decomposed cowdung@1 kg/500 m². Then apply Urea @2.5 kg on 15th and 30th day after planting. Apply irrigation daily for initial three days then apply on alternate day for a week. Then reduce frequency of irrigation. On 40-45days vines are ready for transplantation in main field.

Mostly apical vine cuttings are used as they give higher yield. Vine@20-40 cm length with 3-5 nodes are used for transplantation purpose. In main field plant these vines on ridges or mounds or on flat beds with recommended spacing. Plant vine cutting with middle portion buried in soil.
 

Seed rate:
Near about 30,000-33,000 plants are accommodates in one acre area with spacing of 60x20-30 cm. 40 kg of tubers are required (having weight@125-150 gram) to obtained vine cutting for one acre land.

Seed treatment:
Place the tubers in plastic bag and then soak them in concentrated sulphuric acid for 10-40 minutes.
 

Apply Metribuzine 70WP@ 200 gram per acre or Alachlor@2 litre per acre before sprouts emergence. On 5-10% sprout emergence and ridge are infested with weeds then only apply Paraquat@500-750ml per acre.

After planting, irrigation is given once in 2 days for period of 10 days and thereafter irrigation is given once in 7-10 days. Irrigation must be stopped before 3 weeks of harvesting. But before 2 days of harvesting one irrigation is necessary.

Fertilizer Requirement (kg/acre)

Nutrient Requirement (kg/acre)

Well decomposed cow dung@10 tonnes per acre is mixed before 2-3 weeks of transplanting at the time of land preparation. Overall it required Fertilizer dose of Nitrogen@16-24 kg/acre (Urea@35-55 kg), phosphorus@20 kg (SSP@125 kg) and potash@16-24 kg/acre (MOP@30-40kg). Full dose of Phosphorus and half dose of nitrogen and potash are added at the time of transplanting. Rest of the dose of nitrogen is added after 1 month of transplanting.

• Disease and their control:
  

Black scurf: Black speck observed on tubers. Affected plant show drying up. In infected tubers, at time of sprouting, black, brown color appear on eyes.

For planting use diseased free tubers. Before sowing, seed treatment with Mercury is essential. Avoid mono-cropping and follow crop rotation. If land kept fallow for two years then severity of disease is reduced.

Early blight: Necrotic spots observed on lower leaves. The fungus due which infestation occurred lies in soil. It rapidly spread in high moisture and low temperature.

Avoid mono-cropping of crop and follow crop rotation. If infestation is observed, take spray of Mancozeb@30gm or Copper oxychloride@30gm/10Ltr water at 45 days 2-3 times at 10 days interval.

Common scab: It survives in field as well as in storage. Disease is spread rapidly in low moisture condition. Light brown to dark brown lesion are appeared on infected tubers.

Use only well rotten cow dung for application in field. Use diseased free seeds for planting. Avoid deep planting of tubers. Follow crop rotation and avoid mono cropping in same field. Before sowing, treat seeds with Emisan 6@0.25% (2.5gm/Ltr of water) for five minutes.

• Pest and their control:
  

Sweet potato weevils: They damage the plant by feeding themselves on the epidermis of vines and leaves.
 
Treatment: To control weevils spray of 200 ml Rogor @150 ltr water per acre.

Tuber Moth: It is major pest in field as well as in storage. It make tunnel in potato and feeds on flesh. Use healthy and diseased free seeds for sowing. Use only well decomposed cow dung.

If infestation is observed take spray of Carbaryl@400gm/100ltr of water.

Aphid: Adult and nymphs, both suck the sap thus weaken the plant. In severe infestation, they cause curling and deformation of young leaves. They secrete honey dew like substance and Sooty, black mould is developed on affected parts.

Cut the foliage according region timing, to check infestation of Aphid. If Infestation of Aphid and Jassid observed take spray of Imidacloprid@50ml or Thiamethoxam@40gm/acre/150Ltr water.

The crops get mature after 120 days of planting. Harvesting is mainly done when tubers get mature and the leaves turn yellow. On cutting of tubers, if it gives greenish-black color, then tubers are not ready for harvesting.  Harvesting is done by digging tubers. It gives an average yield of 80-100 Quintal/acre. Avoid delay in harvesting as chances of attack of potato weevil get increases.

After harvesting, they are placed in shade for five to six days for curing purpose. Then cleaning and grading of tuber is carried out.