RED ONION

Group No: 07Export AgricultureRice & Field Crop ProductionEAG 353-2

INTRODUCTIONPlant profile

Family : Liliaceae/Alliaceae Species : Allium ascolonium Distribution: India, Afghanistan, Uzbekistan, Western

Asia, Mediterranean region Uses : Culinary spice

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

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

VARIETIESPusa 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

Agri found light red

Bulbs – Light red & globular Bolting is less & it has good keeping quality They mature in about 160-165 days

DESCRIPTION OF THE PLANTMain 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

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 daysStamens-06,anthers-bilocular,style-1mm longCross pollination is common, effected by

honey-beesSelf pollination also takes place as the insects

visit many flowers in a single umbel

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

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

CULTIVATIONPropagation Propagated by seeds or raising seedlings in the

nursery Then transplanting directly to the field Optimum time for sowing-March to AprilNursery 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

To avoid from damping off disease – treated with Thiram or Captan

Line spacing-5-7cm Well prepared beds are covered with soil

powdered FYMcompost

Mulching- dry straw(maintain required temperature & preserve moisture)

Irrigation- should do regularly till germination is completed with the help of watering cans

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 are8-9 weeks old20-25 cm in height0.6-0.9 cm thick

If younger seedlings are transplanted, the establishment is poor &resulting in a low yield

If over aged seedlings are transplantedOccur bolting problemsTakes long time to start new growth

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)

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

Manures and Fertilizers

Time Kg/haN 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

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/haOxyfluorfen-240g/1 EC 0.5lit/ha

Critical period for weed competition is up to 40 days after transplanting

PEST AND DISEASEPests1.Onion thrips-major pest2.Onion fly(onion maggot)3.Head borer4.Mites5.Tobacco caterpillar6.Cut worms7.Leaf miner8.Beetle9.Ground nut earwig

Diseases1.Damping off2.Purple blotch disease3.Stemphylium blight disease4.Downy mildew5.Onion smut6.Neck rot or bulb rot7.White rot 8.Pink rot9.Bacterial soft rot10.Black mould11.Onion yellow dwarf virus

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

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

Time of harvesting depend on several factors Eg:- Planting season

VarietyMarket 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

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

COLD STORAGEDuring high temperature conditions

onions are kept in cold storage

Best temperature 1-2ᵒC

RH 70%-75%

VALUE ADDED PRODUCTS

Dehydrated onion Onion powder Onion flakes Kibbled onions Onion salt