PENRO CAPITOL

4. GENERAL INFORMATIONGENERAL INFORMATION
ON SWEET POTATOON SWEET POTATO

5. Characteristics:Characteristics:
 TheThe sweet potatosweet potato, commonly called, commonly called yamyam in thein the
United States, is aUnited States, is a cropcrop plantplant whose large,whose large,
starchystarchy, sweet tasting, sweet tasting tuberous rootstuberous roots areare
importantimportant root vegetableroot vegetable. The young leaves and. The young leaves and
shoots are eaten asshoots are eaten as greensgreens..
 The edibleThe 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 frompurple, brown and white. Its flesh ranges from
white through yellow, orange, and purple.white through yellow, orange, and purple.

6. Nutrition and health benefitsNutrition and health benefits
 Besides simple starches, sweet potatoes are rich inBesides 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, theIn 1992, the Center for Science in the Public InterestCenter for Science in the Public Interest compared thecompared the
nutritional value of sweet potatoes to other vegetables. Consideringnutritional value of sweet potatoes to other vegetables. Considering
fiber content, complexfiber 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 moreSweet potato varieties with dark orange flesh have more
beta carotenebeta carotene than those with light colored flesh and their increasedthan those with light colored flesh and their increased
cultivation is being encouraged in Africa where Vitamin A deficiencycultivation is being encouraged in Africa where Vitamin A deficiency
is a serious health problem. Despite the name "sweet", it may be ais a serious health problem. Despite the name "sweet", it may be a
beneficial food forbeneficial 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 lowerrevealed that it helps to stabilize blood sugar levels and to lower
insulin resistance.insulin resistance.

8. USES :USES :
 The roots are most frequently boiled, fried,The roots are most frequently boiled, fried,
or baked.or baked.
 processed intoprocessed into starchstarch
 partialpartial flourflour substitute.substitute.
 Industrial uses include the production ofIndustrial uses include the production of
starchstarch and industrialand industrial alcoholalcohol..

9. CulinaryCulinary usesuses
 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 toIn Korean cuisine, sweet potato starch is used to
produceproduce dangmyeondangmyeon (cellophane noodles).(cellophane noodles).

10. Non-culinary usesNon-culinary uses
 dyedye forfor clothcloth
 All parts of the plant are used for animalAll parts of the plant are used for animal fodderfodder..
 Sweet potatoes or camotes are often found inSweet potatoes or camotes are often found in MocheMoche
ceramics.ceramics.
 Cultivated in gardens as ornamental plants for theirCultivated 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 makingTaiwanese companies are making
alcohol fuelalcohol fuel from sweet potatofrom sweet potato
 Ethnomedical UsesEthnomedical Uses
1.1. TheThe aerial partsaerial parts are used as aare used as a galactogoguegalactogogue..
2.2. TheThe leavesleaves are used to treatare used to treat diabetesdiabetes,, hookwormhookworm,,
hemorrhagehemorrhage, and, and abscessesabscesses..
3.3. TheThe tubertuber is used to treat asthma.is used to treat asthma.

11. ADAPTATION:ADAPTATION:
 The plant grows best at an average temperature of 24The 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 growthlogging, 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, tubersDepending on the cultivar and conditions, tubers
mature in two to nine months. Sweet potatoes rarelymature 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.

12. ADAPTATION:ADAPTATION:
 Propagated by stem or root cuttings or by adventitiousPropagated by stem or root cuttings or by adventitious
roots called "slips" that grow out from the tuberousroots called "slips" that grow out from the tuberous
roots during storage. True seeds are used for breedingroots during storage. True seeds are used for breeding
only.only.
 Under optimal conditions of 85 to 90 % relativeUnder optimal conditions of 85 to 90 % relative
humidity at 13 to 16 °C, sweet potatoes can keep forhumidity 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 haveThey 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, butSweet potatoes are grown on a variety of soils, but
well-drained light and medium textured soils with a pHwell-drained light and medium textured soils with a pH
range of 4.5-7.0 are more favorable for the plant. Theyrange 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.

13. 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 looseat least twice to have loose
and friable soiland friable soil
- Form ridges or furrows- Form ridges or furrows
about 30-40 centimeters highabout 30-40 centimeters high
with a distance of 75-100with a distance of 75-100
centimeters between ridgescentimeters between ridges

14. 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

15.  PlantingPlanting
- Plant vine cuttings diagonally on top of the- Plant vine cuttings diagonally on top of the
ridges (during wet seasonridges (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

16. CULTURAL MANAGEMENT :CULTURAL MANAGEMENT :
 FertilizationFertilization
-- Follow the fertilizer recommendation based on the results ofFollow the fertilizer recommendation based on the results of
the soil analysisthe soil analysis
1. For poor soils, use 4-6 bags complete fertilizer per hectare1. 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 bandhectare 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 after8-10 cm from the base of the or 2 weeks after
planting then cover subsequently with soil.planting then cover subsequently with soil.

17. CULTURAL MANAGEMENT :CULTURAL MANAGEMENT :
 Cultivation & WeedingCultivation & Weeding
- shallow cultivation 10-12- shallow cultivation 10-12
days after plantingdays after planting
- Hilling-up 25-30 days after- Hilling-up 25-30 days after
plantingplanting

18. CULTURAL MANAGEMENT :CULTURAL MANAGEMENT :
PestPest DescriptionDescription Control MeasureControl Measure
WeevilWeevil Most serious pest infecting theMost serious pest infecting the
roots; Infected roots cannot beroots; Infected roots cannot be
eaten by maneaten by man
Burn all infected plants;Burn all infected plants;
Use healthy plantingUse healthy planting
materials; Apply Furadanmaterials; Apply Furadan
3G granules with fertilizer3G granules with fertilizer
NematodeNematode Roots are galled with severalRoots are galled with several
egg masses; Lesion, necrosisegg masses; Lesion, necrosis
and rotting appear usually inand rotting appear usually in
cracked, deformed rootscracked, deformed roots
Treat soil withTreat soil with
Nematicide;Nematicide;
Practice crop rotation;Practice crop rotation;
Use of resistant varietiesUse of resistant varieties
CercosporaCercospora
Leaf spotLeaf spot
Circular lesions which areCircular lesions which are
conspicuous on both sides ofconspicuous on both sides of
the leaf; Spots are dark brownthe leaf; Spots are dark brown
with yellowish brown to graywith yellowish brown to gray
centerscenters
Practice sanitation;Practice sanitation;
Practice crop rotation;Practice crop rotation;
Use of disease freeUse of disease free
planting materialsplanting materials
 Common Plant Pest & Disease & ManagementCommon Plant Pest & Disease & Management

19. 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)

20.  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 ofleaves & bamboos with adequate & proper aeration can retain the quality of
roots for up to 3 monthsroots for up to 3 months

21. RECOMMENDED CROPPING / FARMINGRECOMMENDED CROPPING / FARMING
SYSTEM:SYSTEM:
 Sweet potato is good companion crop for Multi-Storey CroppingSweet potato is good companion crop for Multi-Storey Cropping
System since it can tolerate partial shading. Hence, it is recommendedSystem 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 toSweet potato is also a good cover crop for areas susceptible to
erosion. Cover cropping will reduce surface run-off and evaporationerosion. Cover cropping will reduce surface run-off and evaporation
rate, improve soil structure and hydrology and minimize intrusion ofrate, 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 SPViSCA sweet potato lines (NSIC SP# 30, NSIC SP #25, PSB SP
#17)#17)
 Sydney white and yellow, USA N.C. yellow, Taiwan white andSydney white and yellow, USA N.C. yellow, Taiwan white and
yellow, Hawaii purpleyellow, Hawaii purple

22. POTENTIAL AREAS FOR SWEET POTATOPOTENTIAL 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 ofActual 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.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 areaPotential 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-utilized).planted to coconut, (assumption: 50% of the areas planted to coconuts are under-utilized).
 Projected yield from expansion areas based on present average production rate is 147,000 MT.Projected yield from expansion areas based on present average production rate is 147,000 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