S W Expanded E Trogram

GENERAL INFORMATION ON GENERAL INFORMATION ON SWEET POTATOSWEET POTATO

Characteristics:Characteristics:

The The sweet potatosweet potato, commonly called , commonly called yamyam in the in the United States, is a United States, is a cropcrop plantplant whose large, whose large, starchystarchy, sweet tasting , sweet tasting tuberous rootstuberous roots are are important important root vegetableroot vegetable. The young leaves and . The young leaves and shoots are eaten as shoots are eaten as greensgreens. .

The edible The edible tuberous roottuberous root is long and tapered, is long and tapered, with smooth skin, color ranges between red, with smooth skin, color ranges between red, purple, brown and white. Its flesh ranges from purple, brown and white. Its flesh ranges from white through yellow, orange, and purple.white through yellow, orange, and purple.

Nutrition and health benefitsNutrition and health benefits

Besides simple starches, sweet potatoes are rich in Besides simple starches, sweet potatoes are rich in complex carbohydratescomplex carbohydrates, , dietary fiberdietary fiber, , beta carotenebeta carotene (a (a vitamin Avitamin A equivalent nutrient), equivalent nutrient), vitamin Cvitamin C, and , and vitamin B6vitamin B6..

In 1992, the In 1992, the Center for Science in the Public InterestCenter for Science in the Public Interest compared the compared the nutritional value of sweet potatoes to other vegetables. Considering nutritional value of sweet potatoes to other vegetables. Considering fiber content, complex fiber content, complex carbohydratescarbohydrates, , proteinprotein, , vitaminsvitamins A and C, A and C, ironiron, and , and calciumcalcium, the sweet potato ranked highest in nutritional , the sweet potato ranked highest in nutritional value. value.

Sweet potato varieties with dark orange flesh have more Sweet potato varieties with dark orange flesh have more beta carotenebeta carotene than those with light colored flesh and their increased than those with light colored flesh and their increased cultivation is being encouraged in Africa where Vitamin A deficiency cultivation is being encouraged in Africa where Vitamin A deficiency is a serious health problem. Despite the name "sweet", it may be a is a serious health problem. Despite the name "sweet", it may be a beneficial food for beneficial food for diabeticsdiabetics, as preliminary studies on animals have , as preliminary studies on animals have revealed that it helps to stabilize blood sugar levels and to lower revealed that it helps to stabilize blood sugar levels and to lower insulin resistance.insulin resistance.

USES :USES :

The roots are most frequently boiled, fried, The roots are most frequently boiled, fried, or baked. or baked.

processed into processed into starchstarch partial partial flourflour substitute. substitute. Industrial uses include the production of Industrial uses include the production of

starchstarch and industrial and industrial alcoholalcohol..

CulinaryCulinary uses uses Candied sweet potatoesCandied sweet potatoes Sweet potato pieSweet potato pie Sweet potato friesSweet potato fries Sweet potato leavesSweet potato leaves Steamed/Boiled chunksSteamed/Boiled chunks Sweet potato chipsSweet potato chips Raw sweet potatoesRaw sweet potatoes Sweet Potato ButterSweet Potato Butter Roasted sweet potatoRoasted sweet potato In Korean cuisine, sweet potato starch is used to In Korean cuisine, sweet potato starch is used to

produce produce dangmyeondangmyeon (cellophane noodles). (cellophane noodles).

Non-culinary usesNon-culinary uses dyedye for for clothcloth All parts of the plant are used for animal All parts of the plant are used for animal fodderfodder.. Sweet potatoes or camotes are often found in Sweet potatoes or camotes are often found in MocheMoche

ceramics.ceramics. Cultivated in gardens as ornamental plants for their Cultivated in gardens as ornamental plants for their

attractive foliage, including the dark-leafed cultivarsattractive foliage, including the dark-leafed cultivars Bio-fuel - Bio-fuel - Taiwanese companies are making Taiwanese companies are making

alcohol fuelalcohol fuel from sweet potato from sweet potato

Ethnomedical UsesEthnomedical Uses

1.1. The The aerial partsaerial parts are used as a are used as a galactogoguegalactogogue. . 2.2. The The leavesleaves are used to treat are used to treat diabetesdiabetes, , hookwormhookworm, ,

hemorrhagehemorrhage, and , and abscessesabscesses. . 3.3. The The tubertuber is used to treat asthma. is used to treat asthma.

ADAPTATION:ADAPTATION:

The plant grows best at an average temperature of 24 The plant grows best at an average temperature of 24 °C, with abundant sunshine and warm nights.°C, with abundant sunshine and warm nights.

Annual rainfalls of 750-1000 mm are most suitable. Annual rainfalls of 750-1000 mm are most suitable. The crop is sensitive to drought at tuber initiation stage, The crop is sensitive to drought at tuber initiation stage, 50-60 days after planting and is not tolerant to water-50-60 days after planting and is not tolerant to water-logging, as it may cause tuber rots and reduce growth logging, as it may cause tuber rots and reduce growth of storage roots if aeration is poor.of storage roots if aeration is poor.

Depending on the cultivar and conditions, tubers Depending on the cultivar and conditions, tubers mature in two to nine months. Sweet potatoes rarely mature in two to nine months. Sweet potatoes rarely flower when the daylight is longer than 11 hours. flower when the daylight is longer than 11 hours.

ADAPTATION:ADAPTATION:

Propagated by stem or root cuttings or by adventitious Propagated by stem or root cuttings or by adventitious roots called "slips" that grow out from the tuberous roots called "slips" that grow out from the tuberous roots during storage. True seeds are used for breeding roots during storage. True seeds are used for breeding only.only.

Under optimal conditions of 85 to 90 % relative Under optimal conditions of 85 to 90 % relative humidity at 13 to 16 °C, sweet potatoes can keep for humidity at 13 to 16 °C, sweet potatoes can keep for six months. Colder temperatures injure the roots.six months. Colder temperatures injure the roots.

They grow well in many farming conditions and have They grow well in many farming conditions and have few natural enemies; pesticides are rarely needed. few natural enemies; pesticides are rarely needed.

Sweet potatoes are grown on a variety of soils, but Sweet potatoes are grown on a variety of soils, but well-drained light and medium textured soils with a pH well-drained light and medium textured soils with a pH range of 4.5-7.0 are more favorable for the plant. They range of 4.5-7.0 are more favorable for the plant. They can be grown in poor soils with little fertilizer. can be grown in poor soils with little fertilizer.

CULTURAL MANAGEMENT :CULTURAL MANAGEMENT :

Land PreparationLand Preparation

To have a good root yield of the cropTo have a good root yield of the crop

- plow and harrow the soil - plow and harrow the soil

at least twice to have loose at least twice to have loose

and friable soiland friable soil

- Form ridges or furrows - Form ridges or furrows

about 30-40 centimeters high about 30-40 centimeters high

with a distance of 75-100 with a distance of 75-100

centimeters between ridgescentimeters between ridges

CULTURAL MANAGEMENT :CULTURAL MANAGEMENT :

Planting MaterialsPlanting Materials

- use sprouts from roots or vine tip cuttings - use sprouts from roots or vine tip cuttings

from healthy plants 25-30 cm longfrom healthy plants 25-30 cm long

- cuttings should be stored in shaded place- cuttings should be stored in shaded place

PlantingPlanting - Plant vine cuttings diagonally on top of the - Plant vine cuttings diagonally on top of the ridges (during wet season ridges (during wet season or on the furrows (during dry season) or on the furrows (during dry season) - Expose 2-3 leaves at the tip with a - Expose 2-3 leaves at the tip with a planting distance of 25 – 30 cm per hillplanting distance of 25 – 30 cm per hill

CULTURAL MANAGEMENT :CULTURAL MANAGEMENT : FertilizationFertilization - - Follow the fertilizer recommendation based on the results of Follow the fertilizer recommendation based on the results of the soil analysis the soil analysis 1. For poor soils, use 4-6 bags complete fertilizer per hectare 1. For poor soils, use 4-6 bags complete fertilizer per hectare 2. For moderate soils, 4 bags complete fertilizer per hectare2. For moderate soils, 4 bags complete fertilizer per hectare 3. For fertile soil, fertilization is not advisable.3. For fertile soil, fertilization is not advisable.

- The use of compost or organic fertilizers at 3 metric tons per - The use of compost or organic fertilizers at 3 metric tons per hectare may be used. Apply fertilizer in the furrows/in band hectare may be used. Apply fertilizer in the furrows/in band application.application. - Apply recommended fertilizer at planting time - Apply recommended fertilizer at planting time 8-10 cm from the base of the or 2 weeks after 8-10 cm from the base of the or 2 weeks after planting then cover subsequently with soil.planting then cover subsequently with soil.

CULTURAL MANAGEMENT :CULTURAL MANAGEMENT :

Cultivation & WeedingCultivation & Weeding

- shallow cultivation 10-12 - shallow cultivation 10-12 days days after plantingafter planting

- Hilling-up 25-30 days after - Hilling-up 25-30 days after planting planting

CULTURAL MANAGEMENT :CULTURAL MANAGEMENT :

PestPest DescriptionDescription Control MeasureControl Measure

WeevilWeevil Most serious pest infecting the Most serious pest infecting the roots; Infected roots cannot be roots; Infected roots cannot be eaten by maneaten by man

Burn all infected plants; Burn all infected plants; Use healthy planting Use healthy planting materials; Apply Furadan materials; Apply Furadan 3G granules with fertilizer3G granules with fertilizer

NematodeNematode Roots are galled with several Roots are galled with several egg masses; Lesion, necrosis egg masses; Lesion, necrosis and rotting appear usually in and rotting appear usually in cracked, deformed rootscracked, deformed roots

Treat soil with Treat soil with Nematicide;Nematicide;

Practice crop rotation;Practice crop rotation;

Use of resistant varietiesUse of resistant varieties

Cercospora Cercospora Leaf spotLeaf spot

Circular lesions which are Circular lesions which are conspicuous on both sides of conspicuous on both sides of the leaf; Spots are dark brown the leaf; Spots are dark brown with yellowish brown to gray with yellowish brown to gray centerscenters

Practice sanitation;Practice sanitation;

Practice crop rotation;Practice crop rotation;

Use of disease free Use of disease free planting materialsplanting materials

Common Plant Pest & Disease & ManagementCommon Plant Pest & Disease & Management

CULTURAL MANAGEMENT :CULTURAL MANAGEMENT : HarvestingHarvesting - harvest tubers 90-120 days after planting- harvest tubers 90-120 days after planting - harvesting can be done by root sampling if desired sizes have been - harvesting can be done by root sampling if desired sizes have been

attainedattained - Before harvesting, cut & roll the vines like a mat. Fork/hoe or pass a - Before harvesting, cut & roll the vines like a mat. Fork/hoe or pass a

plow below the ridges. Pick the roots.plow below the ridges. Pick the roots. - Handle the roots carefully to minimize injury- Handle the roots carefully to minimize injury - Sort out tubers (damaged/bruised from undamaged ones)- Sort out tubers (damaged/bruised from undamaged ones)

Post-Harvest TechnologyPost-Harvest Technology - Store roots in clean, dry and well-ventilated storage areas- Store roots in clean, dry and well-ventilated storage areas - Avoid tuber injury during harvest & transport. Place harvested tubers in - Avoid tuber injury during harvest & transport. Place harvested tubers in

wooden/bamboo crateswooden/bamboo crates - Storing roots in an improvised structure made of cogon, nipa, coconut - Storing roots in an improvised structure made of cogon, nipa, coconut

leaves & bamboos with adequate & proper aeration can retain the quality of leaves & bamboos with adequate & proper aeration can retain the quality of roots for up to 3 months roots for up to 3 months

RECOMMENDED CROPPING / FARMING SYSTEM:RECOMMENDED CROPPING / FARMING SYSTEM:

Sweet potato is good companion crop for Multi-Storey Cropping Sweet potato is good companion crop for Multi-Storey Cropping System since it can tolerate partial shading. Hence, it is recommended System since it can tolerate partial shading. Hence, it is recommended in areas planted to coconut to improve land use efficiency.in areas planted to coconut to improve land use efficiency.

Sweet potato is also a good cover crop for areas susceptible to Sweet potato is also a good cover crop for areas susceptible to erosion. Cover cropping will reduce surface run-off and evaporation erosion. Cover cropping will reduce surface run-off and evaporation rate, improve soil structure and hydrology and minimize intrusion of rate, improve soil structure and hydrology and minimize intrusion of weeds.weeds.

RECOMMENDED VARIETIES:RECOMMENDED VARIETIES:

UPLB SP6, UPLB SP8, UPLB, SP23, UPLB SP6, UPLB SP8, UPLB, SP23,

ViSCA sweet potato lines (NSIC SP# 30, NSIC SP #25, PSB SP ViSCA sweet potato lines (NSIC SP# 30, NSIC SP #25, PSB SP #17) #17)

Sydney white and yellow, USA N.C. yellow, Taiwan white and Sydney white and yellow, USA N.C. yellow, Taiwan white and yellow, Hawaii purple yellow, Hawaii purple

POTENTIAL AREAS FOR SWEET POTATO POTENTIAL AREAS FOR SWEET POTATO PRODUCTION IN CEBU PROVINCE:PRODUCTION IN CEBU PROVINCE:

Actual area planted to sweet potato (2007) in the province is 1,220 hectares with a total yield Actual area planted to sweet potato (2007) in the province is 1,220 hectares with a total yield of 8,548 MT, or an average of 7 MT per hectare.of 8,548 MT, or an average of 7 MT per hectare.

Total land area devoted to coconut production is 42,590 hectares.Total land area devoted to coconut production is 42,590 hectares. Potential area for expansion of sweet potato production is 21,000 hectares, 50% of the total Potential area for expansion of sweet potato production is 21,000 hectares, 50% of the total

area planted to coconut, (assumption: 50% of the areas planted to coconuts are under-area planted to coconut, (assumption: 50% of the areas planted to coconuts are under-utilized).utilized).

Projected yield from expansion areas based on present average production rate is 147,000 Projected yield from expansion areas based on present average production rate is 147,000 MT.MT.

PRODUCTION ECONOMICS:PRODUCTION ECONOMICS:

Cost of Production per hectare : P 51,050.00

Production /hectare : 10,000.00 kg/ha.

Sales @ P10.00/kg : 100,000.00

Net Income : 48,950.00