Production technology of Sweet Potato.pptx

Production of sweet potato

1. Sweet Potato/ Spanish Potato

2. Introduction Botanical Name Ipomoea batatas L. (Poir) Family Convolvulaceae Genomic formula 2N=6X= 90 (extremely heterozygous & hexaploid) Edible part Tuberous root Origin South America. Portuguese brought it in to India in early 16 th century. Progenitor Ipomoea trifida

3. Distribution According to FAO, Sweet potatoes are grown in 111 countries , of which 101 are classified as developing nations Among the world’s root crops, sweet potato ranks second only to potato in economic importance. In 2021, the global production of Sweet potato amounted to 88.9 million MT approx. Major countries producing sweet potatoes are- China, Malavi, Tanzania, Indonesia, Vietnam, Angola, Ethiopia, Nigeria, Uganda and USA. China is the largest producer and consumer of sweet potato

4. Area, Production and Productivity (India) India shares 3.22% of global area and 1.88% of global production of sweet potato. According to NHB in 2021 Area under SP production: 128000 ha Production: 1460000 t Productivity: 11.41 t/ha Major States growing (area) : 1 st Odisha, 2 nd UP, 3 rd WB , 4 th MP, 5 th Chattisgarh , 6 th Karnataka, 7 th Assam etc. Production leading states: Orissa > Kerala > W. B . > U. P. > Chhattisgarh Major importing countries from India: UAE > Maldives > Nepal > Japan > Bahrain

5. Botany Perennial vine but grown as an annual crop Produces many trailing stems which seldom rise more than 45 cm above ground Have herbaceous, creeping or trailing stems (vines) with short internodes and semierect growth habit with adventitious roots that ends in swollen roots. Leaves are spirally arranged along the stems.

6. Photoperiodically Short day plant (day length 11.5 hrs) Flower colour White- pink Inflorescence Cymose Nature of pollination Highly cross pollinated due to sporophytic self-incompatibility , honey bee and bumble bee Anthesis 4-5 am Fruit Glabrous or hirsute, dehiscent capsule Seeds Angular, brownish-black seed with hard testa

7. Skin colour Red – Purple – Brown - White Flesh colour White – Yellow – Orange - Purple Root System Can be differentiated into three types String Roots Pencil Roots Tuber bearing roots

8. Differences between tuberous roots and ordinary roots in sweet potato.   Tuberous root Ordinary roots 1. Synthesizes food materials in them They cannot do so 2. Edible Non edible 3. Xylem is having 5 or 6 plates Xylem is having 3 to 4 plates 4. Small pith centre Large pith centre 5. Root primordial is larger Root primordial is smaller 6. Thick roots with different shape and size Thin and long roots 7. Receive Food materials from different plant parts and accumulated Absorb nutrients from soil and supply to different plant parts

9. Nutritional value Nutritional Value per 100 g Energy : 490 kJ Carbohydrate: 25-32 % Ascorbic Acid: 23-25 mg Thiamine (B1): 0.1 mg Riboflavin (B2): 0.05-0.06 mg Niacin (B3): 0.6-0.9 mg Pyridoxine (B6) Pantothenic acid (B5) Ca: 30-34 mg Fe: 0.8-1 mg Mg: 24 mg P: 49 mg K: 373 mg Na: 13 mg

10. Nutritional values Deep orange or yellow coloured varieties are rich in beta-carotene and other biologically active carotenoids Leaves contains more Fe and Ca compared to tubers, but due to presence of oxalate and phytate in in leaves they are poorly absorbed in the body. Only non leguminous plant to contain trypsin inhibitor Mouldy tubers contains ipomeamarone and ipomeamaranol which are toxic to liver and other organs.

11. Uses of Sweet potato Human consumption: sweet potato tuber after boiling, steaming, baking or frying sweet potato floor is processed for Candies, Noodles and Chapatti as a substitute of wheat flour., baked products like golden bread buns biofortified with beta carotene rich sweet potato can add value to rural and urban diet

12. Uses of Sweet potato Industrial products: Starch is used in textiles, paper, cosmetics, food manufacturing industries, preparation of adhesive and glucose., purple colour sweet potato containing anthocyanin is used for commercial production of food colourants ( eg. , Ayamurasaki , Murasakimasari and Akemurasaki cultivars)

13. Use An excellent source of fibre, vitamin B6, E and C. especially raw leaves are rich source of ascorbic acid and some of Vitamin B Good for the heart. Helps in controlling blood sugar due to low glycaemic index. Good for digestion and contains a good amount of starch Have strong immunity and anti-inflammatory properties Helps in relieving stress Leaves are used to treat diabetes, hookworm etc

14. Source Varieties/Hybrids Characteristic features Introduction Triumph Nancy Hall   Clonal selection Sree Nanadani     Sree Vardhani     Sree Bhadra   RAU Rajendra Shakarkand-5 Yield 20 t/ha. In 90-105 days resistant to fusarium wilt and cercospora leaf spot disease.   RS-35 And RS-43   TNAU Kal Megh Round tubers, very early (90 DAP) and yield 26t/ha ANGARU, Hyderabad Cross-4 Yield 20-30 t/ha in 90-105 days; highly susceptible to weevil infestation Others Kiran High starch content (29-30 %) Fortified varieties Bhu Sona Beta carotene rich (12-5-40 mg/100 g) variety.   Bhu Krishna Anthocyanin rich variety Variety: Sweet potato varieties differ in shape, size and colour of leaves, tubers and nature of tuber flesh.

15. Hybridization (CTCRI, Thiruanatpuram ) H41 Sweet and low fibre content   H42     Sree Varsha Double cross hybrid   Sree Ratna A spreading variety with purple skin, organge flesh and excellent cooking quality; yield 20-26 t/ha in 90-105   Sree Arun A spreading variety with pink skin, cream flesh and good cooking quality; yield 20-28 t/ha in 90-100 days.   Sree Varun A spreading variety with pink skin, cream flesh and good cooking quality; yield 20-28 t/ha in 90-100 days.   Sree Kanaka Inter varietal hybrid, short duration and beta carotene rich.   Gauri and Shankar     Pusa Lal Skin red and flesh white   Pusa Sunehri A brown skinned, yellow fleshed rich in carotene; boiled flesh is attractively orange yellow.   Pusa Safed A white skinned variety with white flesh excellent cooking quality.   Pusa Bharati Higher vitamin C and beta carotene

16. Soil: Acid tolerant crop and require optimum pH 5.2-6.7 Well drained sandy loam rich in organic matter is considered the best Liming is necessary. In heavy soils, tuber size is reduced due to improper aeration High sandy soil results in long cylindrical pencil like tubers Sensitive to alkaline and saline condition

17. Climate Require long warm growing season Can be cultivated at a temperature range of 20-27 oC . Areas with an average day temperature of more than 24 oC and average rainfall of 750 mm is more suitable for cultivation. It can not tolerate frost and below 10 ℃ causes death of the plants For tuberization the ideal temperature is 20-25 oC . No tuberization at very high temperature 35-40 oC and below 15 oC Short day with low light intensity ( 18000-40000 Lux ) promote root development while excess of rain fall and long photo period encourages vine growth and reduced tuber yield Sensitive to drought at tuber initiation stage (50- 60 DAP). Sensitive to water logging as poor aeration results in Rotting of tubers and reduce the growth of storage tubers.

18. Propagation: Sexual propagation of sweet potato is limited because of: Delay germination due to hard seed coat, which require scarification, Wide variation in cultivars due to heterogygosity nature, Self-incompatibility i.e., Gametophytic SI, Poor seed setting, less seed content, Plant grown from seeds are poorly developed top growth & tuberous root. Commercial propagation is done by: Stem or Root cuttings and Advantageous root (Clip) that grows out from primary ones during storage .

19. Nursery: Primary Nursery Prepared about 2 months before planting in main field Area: 100 m2 Seed rate: 100 kg medium sized weevil free seed tubers per ha, weighing 125- 150 g each Spacing = 60 cm × 20 cm and 5-6 cm deep , N= 1.5 kg/ 100 m2 as top dressing after 15 days of planting. Irrigation at alternate day till first 10 days and once in 3 days afterward . Vine gets ready for planting in 2nd nursery after 40-45 days . Cut the vine to a length of 20-30 cm for multiplication in second nursery .

20. Secondary Nursery: Vines are used to multiply for planting in main field. Area: 500 m2 , 25-30 cm length cuttings are planted , Spacing should be 60 cm × 20 cm, FYM- 1 kg/m2, Urea of 5 kg in two splits (15 and 30 DAP), ready for planting in main field after 45 days of planting in 2nd nursery.

21. Selection of Planting Material Vines of 20-30 cm length with at least 3-4 nodes are found to be ideal as a planting material Cuttings obtained from apical and middle portion of vines are preferable to get higher sprouting percentage and better tuber yield Preparation of planting material Cuttings with intact leaves are stored under shade for two days before planting in the main field to promote better root initiation, early establishment and higher yield

22. Planting Planting Time Rainfed (Kharif): June - August Irrigated (Rabi)- October - December (Ideal time for vine cutting is late Sep- early Oct.) Major area under sweet potato is planted during rabi season Propagule rate : 40000-50000 cuttings/ha

23. Methods of planting Land is ploughed to a depth of 20 cm and harrowed to pulvarise the soil. The planting methods followed are: Mound: under drainage problem area Ridge: In sloppy area to prevent erosion Furrow: Bhubaneswar and Orissa Flat: Recommended in Bihar Note: Ridge (20-25cm high) method is best followed by furrow and flat methods. Cuttings are planted in soil with both ends exposed and middle portion buried in the soil at 5-10 cm depth i.e. flat planting Vines are also planted in an inclined position with half of its length buried in the soil

24. Spacing Closer spacing is generally recommended to achieve maximum yield Spacing : 30-60 cm between rows and 15-20 cm between plants In Indo Gangetic plains: 30-45 cm x 30-45 cm Spacing of 60 cm x 20 cm can accommodate about 83000 cuttings per ha

25. Manures and fertilizers: FYM: 10 t/ha, N:P:K: 90:80:90 kg/ha (GFR, Bihar), Azospirillum @ 2 kg/ha (Vine dipping) and 10 kg/ha soil application. Full dose of P2O5 and K2O and half dose of N2 should be given at the time of planting, whereas remaining half dose of N2 should be applied one month after planting along with first weeding and earthing up In case of micronutrient deficiencies Zn SO4 (1-2 %) , Ammonium ferric sulphate (1-2 %) and MnSO4 (0.1%) spray are recommended.

26. Weed control: Critical period: 30-45DAP. Later, on weeds are supressed due to smothering effect. Weeding and earthing up along with top dressing between 15-30 days is beneficial. Turning of vine is practiced in sweet potato , pruning back to 20-30cm s also practiced after a month. Turning of vines: the vines are lifted at nodes 30 DAP to prevent rooting and to facilitate better tuber development

27. Irrigation A light irrigation is given after planting, to maintain sufficient moisture, which gives proper establishment to crop Continuous long phase of draught reduces the tuber yield Irrigation at 10-15 days interval should be applied if thereis insufficient moisture Critical stage of moisture supply is 40 (DAP) Growth crack of sweet potato is an important physiological disorder caused due to moisture imbalance.

28. Cropping System SP has been found to grow under different cropping sequence in eastern and southern regions of India Ideal cropping sequence in eastern India are: North Bihar Maize (Kharif)- Sweet Potato (Autumn)- Wheat (Rabi)- Moong (Summer) Maize (Kharif)-Sweet potato- Onion (Rainy) West Bengal Moong (Summer)- Colocasia (Pre-kharif)-Sweet Potato (Autumn) Moong- EFY- SP Orissa Mid-season Paddy (Rainy)- SP- Fallow Maize- SP- Fallow Chhattisgarh Vegetable Cowpea+ SP Intercropping: SP is cultivated as intercrop in cashew orchard upto prebearing period of 5 yrs with recommended dose of fertilizer (60: 40: 60 kg/ha)

29. Harvesting Crop matures in100-135 DAP depending on variety and environmental condition: Early cultivar: 90-105 DAP Mid and Late cultivars: 110-120 DAP Generally harvesting is recommended at 120 DAP Delay in harvesting increases sweet potato weevil infestation Light irrigation 2-3 days before harvesting makes digging easier Yield: 10-20 t/ha depending of variety and cultural practices Upto 30 t/ha yield may be obtained if proper improved cultural practices are followed

30. Post harvest losses SP tubers are subjected to several types of post harvest losses Physical damage Weight loss Pathological decay Sprouting Weevil infestation ( Cylas formicarius )- major cause of storage loss

31. Curing: Curing results in healing of wounds during post harvest handling. It provides barrier to further lossand stops microbial invasion of the tissue Tubers are cured at 30-33 oC temperature and 85-90% Relative Humidity for 5-7 days. It helps in the formation of protective layer (callus) on injured portion i.e., wound healing process. Wound healing process includes- Rapid healing of wounds (Suberization of wounded root surface). To increase toughness of skin (Periderm) and minimise microbial infection.

32. Storage: At 13-16 ℃ temperature and 85-90 % R. H. it can be stored for 6 months Red skinned varieties can be stored better than white skinned variety Storage in sand and sawdust helps limit spoilage and enhance shelf life of the tubers

33. Physiological disorders: Growth crack: Due to excessive moisture or moisture stress, Delay harvesting Control: Use potassium to check tuber cracking

34. Disease: Pox and Scurf are serious diseases in neutral pH. Feathery mottled disease , Mycoplasma disease , Vector- Aphid etc. Control: Use virus free planting materials Insect: Sweet potato weevil , Pest like ants , Feeds on all parts prefers tuberous roots , White grub makes tunnel in the tubers rendering them to bitter for human Control: Use pheromone trap @ 1trap/100 m2