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 “Rice & Field Crop Production”. Note that the information included here is relevant to Sri Lankan condition.

1. RED ONION
Group No: 07
Export Agriculture
Rice & Field Crop Production
EAG 353-2

2. INTRODUCTION
Plant profile
 Family : Liliaceae/Alliaceae
 Species : Allium ascolonium
 Distribution: India, Afghanistan, Uzbekistan, Western
Asia, Mediterranean region
 Uses : Culinary spice

3.  Produces underground bulbs which are edible
 The nutritive value of onion bulbs varies from
variety to variety
 Onions are cooked in several ways in all types of
curries
Ex; they are baked, boiled, fried and used in
the fresh, dehydrated or powder form in soups,
pickles, sauces, etc.
 They are also eaten raw as in salads and relishes
 Owing to the presence of several sulphur
compounds, onion has antiseptic properties

4. Origin and distribution
Origin: The regions of North west India,
Afghanistan, Western Asia, Mediterranean region
Onion growing countries: India, China,
Uzbekistan, Brazil, USA,
Vietnam, Pakistan, etc.
 Major traditional red onion grown areas in Sri Lanka-
Jaffna
Vavuniya
Mulaithevu
Batticalloa

5. VARIETIES
Pusa red
 Bulbs- Bronze-red in color ,globular, moderately
sweet & pungent
 It has a good keeping quality & less bolting
 Bulbs mature in about 160 days
N.53
 Bulbs – Light red , globular in shape,
moderately pungent & sweet
 Bulbs mature in 140-150days

6. Agri found light red
 Bulbs – Light red & globular
 Bolting is less & it has good keeping quality
 They mature in about 160-165 days

7. DESCRIPTION OF THE PLANT
Main characteristics:
 It emits the distinctive and pungent odor when
the tissues are crushed
 Presence of bulbs, consisting swollen leaf-bases
on the underground part of the stem
 Economical important part - ground part bulb
 Leaves are hollow, cylindrical & tapering

8.  Flowers are born in simple umbels at the apex
of the floral stem, white in color
 An inflorescence may continue opening for
two weeks or more
 Plant may be in bloom for more than 30 days
 Stamens-06,anthers-bilocular,style-1mm long
 Cross pollination is common, effected by
honey-bees
 Self pollination also takes place as the insects
visit many flowers in a single umbel

10. ECOLOGICAL REQUIREMENTS
 Can be grown in wide range of climatic conditions
Temperature – 12.5-25 ᵒC(seed germination)
12.8-21 ᵒC (before bulb formation)
15.5- 25 ᵒC (bulb development)
 Very low temperatures in the early stages favours
bolting
 Relatively high temperature as well as long photo
period are essential for good bulb development

11. Soil
 sandy loam –clay
 pH range- 5.8 to 8.0
 Electrical conductivity-around 0.3mm

12. CULTIVATION
Propagation
 Propagated by seeds or raising seedlings in the
nursery
 Then transplanting directly to the field
 Optimum time for sowing-March to April
Nursery Management
 Beds- 0.6 to 1 m in width,3-6m in length, raised
10-15cm above the ground level to avoid water
logging conditions
 For 1 hectare about 8-10kg seeds are sown in
the nursery

13.  To avoid from damping off disease – treated
with Thiram or Captan
 Line spacing-5-7cm
Well prepared beds are covered with
soil
powdered FYM
compost
 Mulching- dry straw(maintain required
temperature & preserve moisture)
 Irrigation- should do regularly till germination is
completed with the help of watering cans

14.  After this, drenching with Thiram/Captan 2g
litre of water should be done at intervals of 7-10
days
 Seedlings are ready when the plants are
8-9 weeks old
20-25 cm in height
0.6-0.9 cm thick
 If younger seedlings are transplanted, the
establishment is poor &resulting in a low yield
 If over aged seedlings are transplanted
Occur bolting problems
Takes long time to start new growth

15. Direct sowing
 Pulverize soil thoroughly and made free of clods
 Sowing can be done by broad casting
 Thin out keeping proper space
 Provide light irrigation immediately after sowing
Land preparation
 Clear the vegetation
 Plough 4-5 times
 At last ploughing apply FYM, zinc sulphate or ferrous
sulphate
 Prepare seed beds, channels, ridges & furrows of
convenient sizes(2-3m wide & 3-5 m in length)

16. Transplanting
 Transplant in the last week of December or in
the beginning of January
 Pruning of the top to the extent of 25% is done
to obtain a higher yield
 Spacing- 15*10cm
 Field should be irrigated immediately after
transplanting- avoid mortality

17. Manures and Fertilizers
Time Kg/ha
N Urea P2O5 TSP K2O MOP
Basal Fertilizer
(2 days before
planting)
30 65 45 100 30 50
First top dressing
(3 weeks after
planting)
30 65 - - - -
2nd top dressing
(6 weeks after
planting)
30 65 - - 15 25

18. WEEDING
 Hand weeding-difficult and may also damage
the crop(because onion is a closely planted &
shallow rooted crop
 Manual weeding- expensive
 Chemical weeding-gives very good results
 Recommended weedicides
 Alachlor 480 g/1 EC 3-5 lit/ha
 Oxyfluorfen-240g/1 EC 0.5lit/ha
 Critical period for weed competition is up to 40
days after transplanting

19. PEST AND DISEASE
Pests
1.Onion thrips-major pest
2.Onion fly(onion maggot)
3.Head borer
4.Mites
5.Tobacco caterpillar
6.Cut worms
7.Leaf miner
8.Beetle
9.Ground nut earwig

20. Diseases
1.Damping off
2.Purple blotch disease
3.Stemphylium blight disease
4.Downy mildew
5.Onion smut
6.Neck rot or bulb rot
7.White rot
8.Pink rot
9.Bacterial soft rot
10.Black mould
11.Onion yellow dwarf virus

21. IRRIGATION
 At the initial stages of the crop water
requirement is high
 It is necessary to irrigate about 3 day
intervals
 Irrigation drainage improving is very
essential
 Two weeks before harvesting water
supply should be stopped

22. HARVESTING &YIELD
 Should be harvested at the appropriate stage of
maturity
 It is a deciding factor in the storage life and quality of
onions
 Early harvesting-results in the sprouting of the bulbs
 Late harvest gives rice to the formation of secondary
roots during storage
 Important harvest indices
 development of a red pigment
 characteristic pungency of the variety

23.  Time of harvesting depend on several factors
 Eg:- Planting season
Variety
Market price etc.
 Harvesting starts when 25%-50% of the neck falls
 It is recommended to fell the other tops manually,
before harvesting the crop
 The bulbs are harvested by pulling them out large
scale

24.  After harvesting onion along with the tops are
placed in windows in the field for 2 to 3 days
 Tops are cut of either in the field or in the shade
if the sun is strong

25. COLD STORAGE
During high temperature conditions
onions are kept in cold storage
Best temperature 1-2ᵒC
RH 70%-75%

26. VALUE ADDED PRODUCTS
 Dehydrated onion
 Onion powder
 Onion flakes
 Kibbled onions
 Onion salt