This presentation is done by 2010/2011 batch of Export Agriculture students of Uva Wellassa University of Sri Lanka as a requirement for the subject which is “Fruit & Vegetable Cultivation”. Note that the information included here is relevant to Sri Lankan condition.
3. INTRODUCTION
• Potatoes (Solanum tuberosum) are a
member of the family Solanaceae
• More than a billion people worldwide eat
potato
• The potato is the third most important
food crop in the world after rice and
wheat in terms of human consumption
www.potatoesforschools.org.uk
4. • Introduced it to Sri Lanka in 1850's
• At present, potato is extensively
cultivated in the district of Nuwara Eliya
in two major seasons, "Yala" and
"Maha"
• It also widely grown in Badulla District in
paddy fields and high land during "Yala'
and "Maha" seasons respectively
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5. • Puttlam and Jaffna are the other
two districts where the potato is
grown in lesser extent
ECOLOGICAL REQUIREMENTS
• Annual rainfall is >2,500mm
• Temperature ranges between 10-
150C
• Relative humidity of 80%
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6. Morphology
• An erect, perennial, aromatic
herb up to 1 m tall
• Sparsely hairy, with tuber-bearing
underground stolons
• Stems erect, succulent, winged,
branching
• The tuber is morphologically a
flesh stem bearing buds and
eyes in the axile of small scale
like leaves
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7. • Leaves: Divided into 3–5 pairs of leaflets
• The leaves are compound and
alternate, irregularly odd pinnate
• Flowers: White to pink, purple or blue
• The seeds are produced in a berry
• Fruits: A succulent (but inedible), spherical,
yellow-green to purple berry, up to 4 cm in
diameter
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8. Recommended Varieties in SL
Thousands of cultivars are available, which vary in
characters such as tuber size, shape and skin color
Sita
Krushi
Lukshmi
Manike
Desiree
Granola
Kondor
Isna
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9. Factors to consider when choosing a
variety
• The farmer needs to consider the following
when choosing his variety
• Consumer’s choice (Saleability)
• Yield
• Maturity
• Disease resistance
• Seed availability
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12. Preparation of seedbed
• Deep plough the soil to a depth of 22-25cm
• All stones should then be removed
• Stones can bruise potatoes (allowing infection)
during harvesting and must be removed.
• Stones can be removed by hand or a machine
called a de-stoner
• The soil is then cultivated into ridges, using a
specialised machine
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13. • A ridge is a raised area of soil into which the seed is
sown
• Ridges should be between 75 – 90 cm wide and
15cm deep
• Wide ridges lesson potatoes “greening”, lesson
compaction and give greater yields
• Ridges prevent the seed from water logging
• Seeds are sown into the ridges at a depth of 10 cm
below surface- 76cm apart
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14. • The spacing of the seed in the ridges is governed by the
size of the seed
• As seed size increases the number of eyes / auxiliary
buds per tuber increases
• This protects the seed from excess sunlight
• Seed should be sprouted before sowing as it speeds up
growth, plant emergence and yields
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15. Field Establishment
• Potatoes are planted in open ridges or drills
• They are earthed up or moulded and harrowed
down at intervals
• Earthing up is carried out when the crop is 20-
25cm high
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16. • A ridger is used to deepen the furrows and widen
the ridges
• At the end of the growing season, the plant's
leaves and stems die down to the soil level and its
new tubers detach from their stolons
• The tubers then serve as a nutrient store that
allows the plant to survive the cold and later
regrow and reproduce
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17. Irrigation
• Potatoes need frequent irrigation
• The first irrigation should be given immediately
after sowing
• Thereafter at one week intervals
• After tuber formation, the frequency of irrigation
is decreased
• Care must be taken while irrigating that the water
does not reach fee top of the ridge
• Irrigation should be stopped a few days before
harvesting
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18. Earthing Up
• Earthing up is an important post sowing
cultivation of the potato crop
• When the plant is 15 – 20cm high, a ridger is
used to bank up more soil around the stem
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19. • Earthing up prevents greening
• Harrowing: kills all germinating annual weeds
• This helps keep air in at the roots of the plants
• When potato haulms meet across the drill, the
weeds will be controlled
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20. Earthing up is important because;:
• It keeps the soil loose
• Prevents greening of potatoes
• Stops annual weeds from germinating
• Can help to prevent disease (blight)
• Can help to increase yield
www.potatoesforschools.org.uk
21. Soil suitability
• The ideal soil is a deep well-drained, medium
heavy loam with as few stones as possible
• High pH should be avoided
• Optimum pH should be about pH 5 or 5.5
• The soil must be frost free, so coastal areas
are very suitable
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22. Diseases
• Potato blight – a fungal disease which
can affect plants in humid weather
• Blackleg – a bacterial disease which
thrives in wet conditions
• Gangrene – fungal
• Common scab – bacterial disease which
thrives in soils with high pH
• Potato mosaic – viral disease spread by
aphids
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23. Potato Blight
• Potato Blight or Phytophtora infestans is a
fungal disease
• Symptoms-browning and subsequent
blackening of the leaves and rotting of the
tubers
• It causes premature death of haulms with
resultant yield losses
• This leads to infection and rotting during
storage
• The spread of potato blight is favoured by
warm humid weather conditions
www.potatoesforschools.org.uk
25. Preventing Blight
• Do not sow seeds showing any signs of
blight
• Earthing up creates greater distance
from zoospore and tuber
• Remove all tubers at harvest (known as
volunteer potatoes)
• Spray with contact or systemic fungicide
throughout the growing season, every
10 – 14 days
• Remove haulms before harvesting
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26. Preventing Diseases
• Diseases are prevented by spraying
fungicides every 7 – 10 days
• There are different types of fungicides:
• 1)Systemic: goes to all parts of the
plant and is best when the
growth is rapid
• 2)Contact: only protects what it
touches
• 3)Translaminar: spreads all over leaf
and protects it
• Spraying insecticides kills aphids and
prevents viral diseases
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27. Pests in potato cultivation
The main pests of potatoes are:
•Wireworms – can eat into tubers, common
after grass, prevented using poison baits
•Slugs – eat into tubers, high numbers during
wet summers, killed using slug pellets
•Aphids – eat plant and carry viral diseases,
controlled using insecticides or ladybirds
•Potato nematode and eelworms – eat into
tubers, controlled by crop rotation
www.potatoesforschools.org.uk
29. Weed Control
• Crops are sprayed with a contact herbicide when one
quarter of plants have appeared over the soil
• A contact (residual) herbicide kills all plant tissue it
comes in contact with
• This allows for weeds to be controlled until “shading”
occurs, which naturally prevents weeds
• Shading refers to the time when plants meet across
ridges
• Earthing up also prevents weeds
www.potatoesforschools.org.uk
30. Nutrition: Fertilizer
Requirements
• Soil should be tested before applying
fertilizer to determine what is requirement
and how
• Typical Application Rates:
• Nitrogen: 125 – 150 kg / ha
• Phosphorous: 125 – 150 kg / ha
• Potassium: 250 – 300 kg / ha
• 10:10:20 or 7:6:17 Sulphate of Potash are
ideal for potatoes
• Fertilizer should be applied prior to sowing
www.potatoesforschools.org.uk
31. • Fertilizer application must be balanced
• Nitrogen increases yields but decreases dry
matter
• Avoid excess nitrogen as it gives higher yield
but lowers eating quality and can lead to
blight susceptibility
• Phosphorous increases blight resistance and
increases dry matter
• Potassium increases tuber size
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32. Harvesting
• Potatoes are harvested from May/Early June on
depending on variety and part of the country
• Main crop potatoes are harvested in late
September or October where tubers are fully-grown
and mature
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33. Storage
Buildings which store the potatoes must be
•leak proof
•frost proof
•Potatoes are also covered with a layer of straw to
protect against frost
•well ventilated to prevent sprouting and rotting.
•large enough to allow easy access of tractors and
trailers.
•Temperature 4-6 0C
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34. Food value and final use
• Potatoes are a versatile, carbohydrate rich food
highly popular worldwide and prepared and served
in a variety of way
• The potato is a moderate source of iron, and it has
high vitamin C
• It is a good source of vitamins B1, B3 and B6 and
minerals such as potassium, phosphorus and
magnesium.
www.potatoesforschools.org.uk
1.Sprouts develop from eyes on seed tubers and grow upward to emerge from soil,roots begin to develop at the base of emerging sprouts
2.Leaves and branch stems develop fro above ground nodes along emerged sprouts
3.Tubers from stolon tips,but not yet enlarging
4.Tuber cells expand with accumulation of water,nutrients,and carbohydrates
5.Vines turn yellow and loss leaves,ps.decreases.tuber growth slows and vine eventually die