Purbanchal University

G.P. Koirala College of Agriculture and Research

Centre
GPCAR
Gothgaon, Morang

Presentation on
SWEET POTATO

Submitted By Submitted To

*Astha Karki Mr. Krishna Dahal

*Begam Chaudhary
*Chetana Roy Asst. Lecturer,
*Dipshan Bhattarai GPCAR

Semester, GPCAR
 Introduction
• Scientifically known as Ipomoea batatas
• Important tuber crop of tropical and subtropical
regions.
• Grown for their edible tubers & mainly utilized as
human food stuff.
• Tuber are eaten straight from the ground as
vegetable, after boiling, baking or frying.
• Secondarily used as a source of starch in textile,
paper, cosmetic and food manufacturing industries
and for the preparation of adhesives and glucose.
• Tubers are chief source of starch and alcohol.
• Contains 10% starch and contains 3% to 6% sugar.
• Good source of Vitamin A, B, C.
• Orange and orange flesh varieties have more
carotene content.
 Botanical Classification
• Kingdom: Plantae
• Phylum: Magnoliophyta
• Class: Eudicotyledons
• Order: Solanales
• Family: Convolvulaceae
• Genus: Ipomoea
• Species: Ipomoea batatas
 Origin and Distribution
• South America has been widely recognized as
the centre of origin of sweet potato.
(Thompson and kelly, 1957)
• At present times, it is widely distributed to all
the subtropical and tropical regions around
the world.
• China is the cultivation hub of sweet potato
with an average yearly production of 45 kt of
sweet potato as of 2020.
 Botany
• Annual crop with perennial vine.
• Each plant produces many tralling stems and seldom
rises more than 45 cm above the ground.
• Contain herbaceous, creeping or tralling stem with
short internodes and semi srect growth habit with
adventitious roots.
• Leaves spirally arranged along the stems.
• Flowers are solitary or cymose and vary in color from
white to deep purple.
• The fruit is glabrous.
• The root tubers vary in shape, size, color,and food
quality depending upon the varieties.
 Varieties
• There are several local varieties of sweet
potato grown in Nepal.
• The major varieties grown in Nepal are Pusa
Lal, Pusa saffaid, Pusa Sundhari, Co-1, Co-2,
Co-3, H-41, H-42,S-30 etc.
 Exotic varieties
• Purple sweet potato
• Japanese Sweet potato
• Stokes Purple Sweet potato
• White sweet potato

• Recommended varieties
• Beaurgard
• Jewel
• Covington
• Garnet

• Reference: USDA Agricultural Research service (2021)

 Climate and Soil
• Sweet potato is essentially the crop of tropical
and sub tropical climate and prefers long
moderate warm and moist season with plenty
of rainfall.
• The optimum temperature for growth and
tuber formation is 21-26 degree celcius.
• Pregers well drained sandy loam soil
• Ph of 5.2-6.7 is ideal for its optimum growth.
 Planting Season
• Varies depending upon variety cultivated and
region in which we are located,
• Generally, Sweet potato is a warm weather
crops requiring long growing season.
• In Terai, planting is done during march-
april(Chaitra–Baisakh)
• In mid hills- September-October(Ashoj-Karthik)
• Low hills- March-July(Chaitra-Ashad)
 Spacing
• A closer spacing is generally recommended for
sweet potato to achieve maximum tuber yield.
• A distance of 45-60cmX 80-100cm (P-P X R-R)
• 60X20 is ideal for low space acquiring varieties
which will accommodate 40000-50000
cuttings/ha.
• Tube or slips rate: 37,000 to 45,000 slips or
tubers to cover one hectare.
 General guidelines for Planting sweet
potatoes
• Soil temperature should consistently be above
50 degrees farhenheit(10*C)
• Avoid frost as they are frost sensitive plants.
• It is ideal to plant sweet potatoes between late
spring and early summer.
• They require consistent moisture, especially
during first few weeks after planting.
• Avoid excessive nitrogen fertilizers, as they can
result in lush foliage but few tubers.
 Propagation
• Vegetatively propagated through vine cuttings and sprouts
or draws produced from tubers.
• 1. Vine Cuttings from mature plant: Vines are taken in
March-April, cutting size 30cm is taken from terminal
portion of matured crop.Each cuttings shoul have at least
4 buds. Spacing of 60cmX30cm is taken. Cuttings are
planted in june-july.
• 2. Cuttings from Sprouted tubers: Tubers are planted in
nursery bed with 45X30 spacing which sprout after 40-45
days. 20-30cm long cuttings are prepared from sprouts
and are transplanted to the main field in june-july.
Tuber sprouting
 Manure and Fertilizers
• 10-15 ton FYM per hectare is suitable.
• N:P:K-90:40:60 is recommended however we
must note that excessive nitrogen might
decrease yield quality and quantity.
• Nitrogen is applied in split doses.
 Method of planting
• At first healthy slips are selected for planting. Slips are small
sprouts that grow from mature tubers.
• Each slip must be about 10 inches long,
• A well draining sunny location is chosen with ph around 5.5-
6.2.
• Weeds are removed & soil is loosen to a depth of 8 to 10
inches.
• A raised bed is prepared to plant the slips.
• Mulching can be done for better yield.
• The tubers are ready to harvest around 90 to 120 days after
planting.
 Harvesting
• Yield of 10-25 ton/ha of fresh tubers is
obtained on an average.
• Harvesting must be done before frost in high
hills.
• Cure the harvested sweet potatoes by placing
them in warm and humid environment for a
week or two, which helps to develop their
sweetness and harden the skin.
 Physiological disorders
• Internal Cork: Development of dry, corky
tissues within the sweet potato flesh. It is
caused by environmental stress(high tempr,
drought)
• Fusarium Root rot: Fungal disease resulting
into wilting, stunted growth and development
of dark, necrotic lesions on the roots.
• Internal sprouting: Tubers develop sprouts or
shoots inside the tuber caused by improper
storage, high temperature, excessive moisture.
*Hollow Heart: Development of cavities or
hollow spaces in the sweet potato flesh caused
by rapid changes in temperature during tuber
development.
*stem End Rots: Fungal disease that affects the
ends of sweet potatoes usually during storage
or transportation caused by improper handling
during storage and transportation.
 Insect, Pest and Disease
Insect Pests
• Sweet potato weevils
• Sweet potato whiteflies
• Sweet potato flea beetles
• Wireworms
• Slugs and Snails
• Cutworms
Sweet Potato Weevil
Sweet Potato Red Rug
Leaf Eating Caterpillar
Sweet Potato White Fly
 Disease/Pathogens
• Sweet potato Canker
• Fusarium wilt
• Black rot
• Alternaria Leaf Spot
• Rhizopus Soft Rot
• Sweet Potato Leaf Curl Virus
• Sweet potato feathery Mottle virus
• Sweet potato Chlorotic stunt Virus
 Preventive Measures
• Plant Tubers in raise beds.
• Choose a well draining sandy loam soil
• Soil drenching with fungicides prior to
planting.
• Provide recommended spacing for plants.
• Avoid excessive application of N fertilizer.
• Harvest, handle, store and transport tubers
with care.
• Perform curing of tubers after harvest.
 Preventive Measures
• Implement IPM practices.
• Select disease resistant varieties.
• Perform regular inspection and gather data.
• Perform crop rotation and avoid planting in the
same field for consecutive years.
• Install Light trap, pheromone trap for insect pest
management.
• release parasitoids & Microbial pathogens in the
field for Disease management.
THANKYOU
Any Queries???