ONION STORAGE TECHNOLOGY

1. ONION (Allium cepa L- Alliaceae)
HARVESTING AND STORAGE
TECHNOLOGY
Dr Jai Singh (ARS)
M. Tech Ph D
Former Director ICAR – CIPHET
E – Mail: jsingh.sre@gmail.com

3. ONION USES
•VEGETABLES VARIOUS FORMS, SALAD.
•CURRIES – FRIED, BOILED OR BAKED.
•PROCESSED FORM – FLAKES, POWDER,
PASTE, CRUSH, PICKLES.
•THERAPEUTIC VALUE – STIMULANTS, MILD
COUNTER IRRITANT.
•HERBAL REMEDY – COLD, COUGH,
BRONCHITIS, CARDIO VASCULAR
DISEASES, DIABETES, RESPIRATORY
TRACTS, CANCER , ETC.

4. PRODUCTION STATUS IN INDIA
(MIN OF AG, COOPERATION AND FARMER
WELFARE (2015 - 16)
•2ND LARGEST PRODUCER = 202.14 LAKH TONNES
•CROP GROWN AREA =11.67 LAKH Ha
•MONTHLY CONSUMPTION IN COUNTRY = 12 – 15
LAKH TONNES
•STORAGE OF ONION IN INDIA = 45 – 46 LAKH
TONNES
•MAJOR STORING STATES – MAHARASHTRA,
GUJRAT, RAJASTHAN, MADHYA PRADESH &
BIHAR

5. GROWING SEASONS IN INDIA
AND PRODUCTION (SD H& AG 2016– 17)
•RABI : ( 60 % PRODUCE) – APRIL TO
MAY ( 136 LAKH TONNES )
•KHARIF : ( 20 % PRODUCE ) –
OCTOBER TO DECEMBER (31 LAKH
TONNES)
•LATE KHARIF : ( 20 % PRODUCE ) –
JANUARY TO FEBRUARY ( 42 LAKH
TONNES )

6. STATE STORAGE LAKH TONNES
MAHARASHTRA 18.00
MADHYA PRADESH 13.50
GUJRAT 1.25
BIHAR 3.75
UP 3.50
RAJASTHAN 1.00
KARNATAKA 0.40
HARYANA 1.75
PUNJAB 1.25
TAMILNADU 0.18
ODISA 0.35
WEST BENGAL 0.75
TOTAL 48.73
ONION STORAGE IN MAJOR
GROWING STATES

7. MONTH FIVE YR AVERAGE (000
TONNES)
JAN - FEB 2064
MARCH - APRIL 1809
MAY - JUNE 2053
JULY - AUGUST 1311
SEPT - OCTOBER 1341
NOV - DECEMBER 1739
ALL INDIA MONTHLY ARRIVALS IN MARKET
(AGMARKNET 2011 – 2015 )

9. M0NTH LAKH
TONNES
APRIL - MAY 3.1
JUNE - JULY 2.41
AUG - SEPT 3.96
OCT - NOV 5.17
DEC - JAN 4.99
FEB - MARCH 4.53
TOTAL 24.16
EXPORT OF FRESH ONION
(APEDA – 2016)

10. ONION AVAILABILITY IN DOMESTIC
MARKET
KHARIF / LATE KHARIF – MID
OCT0BER TO MID MARCH
RABI - JUNE TO OCTOBER

11. ONION RECOMMENDED PLANTING
METHOD
(ICAR - NRC ONION AND GARLIC )
•BROAD BASED FURROWS – HIGHER
YIELD, BIGGER BULB
•IRRIGATION – DRIP OR SPRINKLER

12. BROAD BED ONION PLANTING
( ICAR – DOGR)

13. IMPROVED ONION VARIETIES INDIA
– ICAR - DOGR –FROM LEFT TO RIGHT-
Bhima Super, Bhima Dark Red, Bhima Red, Bhima Shweta,
Bhima Shubhra

14. SN PROPERTY EFFECT
1 PHYSICAL:- MASS,
VOLUME, BULK
DENSITY, POROSITY
DECREASE – MASS 24 %, VOLUME 17 %,
BULK DENSITY 25 % AFTER 90 DAYS
STORAGE.
2 GEOMETRICAL :-
SIZE, SHAPE,
SURFACE AREA
19 – 20 % REDUCTION AFTER 90 DAYS
STORAGE
3 POROCITY:- 75% INCREASE AFTER 90 DAYS
STORAGE
4 FILLING ANGLE OF
REPOSE;-
REDUCTION 39 %
ENGINEERING PROPERTIES OF ONION
(THE DATA INDICATED ARE AVERAGE
IRRESPECTIVE OF CULTIVAR AND AREA)

15. THERMAL:-
SPECIFIC HEAT,
THERMAL
CONDUCTIVITY,
DIFFUSIVITY:-
SPECIFIC HEAT, THERMAL
CONDUCTIVITY DECREAS
REDUCTION IN MOISTURE
CONTENTWITH STORAGE TIME.
THERMAL
DIFFUSIVITY AND
VOLUMETRIC
HEAT CAPACITY
INCREASES WITH REDUCTION IN
MOISTURE CONTENTWITH
STORAGE TIME
ENGINEERING PROPERTIES OF ONION

16. TEXTURAL
PROPERTIES:-
PENETRATION /
CRUSHING LOAD
CRUSHING STRENGTH REDUCES
AROUND 52 % / IN FRESH IT IS TWICE
THAN 90 DAYS OLD, PUNCTURE /
PENETRATION STRENGTH REDUCES
AROUND 13 %. AFTER 90 DAYS
COLOUR :- DECREASES AROUND 4 % WITH
STORAGE PERIOD.
TSS:- INCREASES 10 – 14 % WITH
STORAGE PERIOD
ENGINEERING PROPERTIES OF ONION

17. OBJECTIVE OF STORAGE
TECHNOLOGY
•TO MAINTAIN BULB IN UNCHANGED SOUND
CONDITION.
•TO MAINTAIN LONGER SELF LIFE.
•TO TRANSPORT WITH MINIMUM LOSSES.
•MARKETING & HANDLING WITH MINIMUM
LOSSES.
•TO REMOVE HEAT AND WATER VAPOUR.
•TO CHECK MARKET GLUT.
•OFF – SEASON AVAILABILITY.
•ENTREPRENEURSHIP DEVELOPMENT
•EXPORT

18. LOSSES IN ONION
Rs1336 CRORES 2016 - 17
•LOSSES = 25 – 30 %
•MOISTURE LOSS AND SHRINKAGE
= 30-- 40 %
•ROTTING = 20 – 30 %
•SPROUTING LOSS = 20 – 40 %
•WASTAGE IN COLD STORAGE = 3 –
4 %

19. ONION STORAGE PARAMETERS
(For Effective Long Storage)
Bulb size, Choice of Cultivars,
Cultivation Practices, Time of
Harvest, Field Curing, Removal of
Tops, Drying, Grading,
Packing, Storage Conditions
(optimum storage range of R H 65% to 70% ,
temperature ranging 27 TO 35 DEG C)

20. Contd -- Storage Parameters
Pre and Post Harvest Factors /
Conditions
Curing Techniques followed
Storage Techniques (temperature,
relative humidity, controlled
atmospheres)
 Handling and Local Transport
Major Quality Features
Utilization Processes and Methods

21. Contd ----STORAGE PARAMETERS
•VENTILATION LIFE LINE TO ONION
•CURING
•COOLING
•TEMP HOLDING
•DEHUMIDIFICATION

22. SEALING THE BULB OUTER LAYER AND
NECK
•DRY THE BULB AND LEAVES BY CURING.
• FIRST THREE GRY LAYERS SEAL THE
BULB FROM OUTER ENVIRONMENT.
•WEIGHT LOSS STOPS / MINIMISES
•SEALED LAYER PROTECTS AGAINST ROT
AND FUNGI
•MININISE TEMP FLUCTUATION TO PREVENT
SPROUTING
•STORE IN DARK LIGHT PROMOTES
SPROUTING
•SLOW VENTILATION IMPROVES QUALITY

23. Pre-harvest treatment
0.4 ppm Mepiquat chloride plus
1000 ppm Carbandazim spray on
onion foliage two weeks prior to
harvest recommended

24. PRE- HARVEST ROLLING KHARIF
CROP for SELF LIFE
•KHARIF CROP MATURES IN 90 – 105 DAYS
•NECK FALL DO NOT OCCUR
•ROLL CROP BY EMPTY BARREL 2 – 3 DAYS
BEFORE HARVEST FOR NECK FALL
•BETTER TREATMENT FOR SELF LIFE

25. HARVESTING OPERATION PREPARATION
DECIDE PURPOSE
•GREEN ONION FOR VEGETABLE – 90 DAYS
•STORAGE AND LATER MARKETING - 115 DAYS
READY TO HARVEST
•KHARIF CROP – LEAVES COLOUR SLIGHT
YELLOW AND RED PIGMENTATION ON BULB.
•RABI CROP – 50 % TOPS FALLEN
•DRIED BULB FOR STORAGE – TOPS START
FALLING i. e. GOING DOWN

26. ONION HARVESTING METHODS
a. HAND PULLING
b. UPROOTING BY KHURPI
c. POTATO DIGGER
d. UNDER CUTTER ONION DIGGER

27. HARVESTING METHODS
HAND PULLING
UPROOTING BY KHURPI / SPADE
POTATO DIGGER
UNDER CUTTER ONION DIGGER

28. MECHANICAL
ONION
HARVESTER

29. ONION CURING
Improves colour , storability /
keeping quality of onion bulbs and
reduces the chance of infection by
disease-causing organisms in
storage.

30. ONION CURING - OBJECTIVE
•SURFACE DRYING - EXCESS
MOISTURE REMOVAL FROM OUTER
SKIN, NECK, ROOTS.
•TO WITHER THE BULB NECK AND
TIGHTENING PAPERY SKIN TO SEAL
OUT MOISTURE
•TO DEVELOP GOOD SCALE COLOUR
•CURE FOR 2 – 3 WEEKS UNTIL TOP
NECK GETS COMPLETELY DRIED

31. Onion Curing Mechanics
•Fresh onion bulbs contains sugary
juices and wear light skin cover.
•Dry skin works as papery wrappers.
•Pungent compound replace sugars.
•Bulb neck gets tightened.
•Seals out moisture and
microorganisms.
DR JAI SINGH

32. CURING
1 CURING RATE GRADUAL REDUCTION WITH
STORAGE PERIOD
2 MATURTY STAGE
EFFECT ON
CURING
FULLY MATURE TAKES LESS
TIME, IMMATURE TAKES LONGER
TIME
3 EFFECT OF
DEPTH OF ONION
STACK ON
MOISTURE LOSS
PHYSIOLOGICAL WEIGHT LOSS
INCREASES WITH DEPTH 10 CM
TO 30 CM
4 MINIMUM FIELD
CURING PERIOD
7 DAYS

33. CURING
METHODS
FIELD CURING 7- 12 DAYS. WITHOUT CURING WEIGHT LOSS
INCRESES ( 12 % - 16 %)
WINDROW CURING BEST METHOD FOR 10 – 12 DAYS, REGULAR
TURNING REQUIRED, BULBS SHOULD NOT
TOUCH WET GROUND
ARTIFICIAL /
MECHANICAL:- STACK
HEIGHT 1.2 M, CURING
TEMP 27 – 45 DEC C,
AIR FLOW 222 CUM /
MIN, RH 20 – 30 %
TAKES 14 – 24 HRS.
RESULTS IN MINIMUM WEIGHT LOSS,
MAXIMUM COLOUR, MORE FIRMNESS
COMPARED TO FIELD CURING.
BULK CURING :- 35 to
45°C TEMP, RH 60 - 75 %
SLATTED FLOOR DRIER

34. ONION CURING METHODS
FIELD CURING:
WINDROW CURING:
SHADE / NATURAL CURING:
SHADE / GREEN HOUSE, HOOP
HOUSE CURING:
BULK CURING
EMERGENCY CURING
MECHANICAL / ARTIFICIAL / HOT AIR

35. FIELD CURING IN DRY SEASON
•PULLING / LIFTING / DIGGING BULBS.
•BUNDELING / SMALL HEAPING / SWATHING.
•LEAVING IN FIELD FOR 10 – 15 days to
remove excess moisture from outer skin and
neck of bulbs.

36. WINDROW CURING
•PLACING DUG OUT BULBS IN WINDROWS
WITH LEAVES OF ONE ROW COVERING THE
BULBS OF NEXT ROW PROTECTING BULBS
FROM SUN BURN
•TURN WINDROWS REGULARLY FOR EVEN
CURING.

37. NATURAL CURING
KEEP THE HARVESTED ONION IN WARM DRY
PLACE FOR A MONTH OR SO

38. SHADE / GREEN HOUSE, HOOP
HOUSE CURING:
After field curing the bulb tops are
cut leaving 2 cm neck on the bulbs and
dried in shade for 15 days.

39. DEHYDRATION PROCESS CURING
The perfect Dehydration Process makes
the Onion free from Moisture and it gives
a long shelf life without losing the
Aroma, Taste, Flavour and Pungancy.

40. MECHANICAL / ARTIFICIAL / HOT AIR
MECHANICAL :BLOWING HOT AIR (22 – 28
DEG CELCIUS) FOR SIX WEEKS . NECKS
WILL GRADUALLY WITHER AND PAPERRY
SKIN WILL TIGHTEN

41. BULK CURING OF ONION
Onions in bulk are kept in well ventilated
stores and dried with artificial heat
blown through the bulk at a duct
temperature of 30 degrees Celsius, AIR
FLOW 1000 – 1200 CUM / HR.

42. Emergency curing of onions
USED WHEN SUDDEN RAINS FLOOD / WET
THE HARVST PRODUCE. LOAD THE
PRODUCE ON SLATTED RACKS AND BLOW
NATURAL HOT AIR OR HEATED AIR 75 TO 80
DEG C FOR 3 WEEKS.

43. STORAGE TECHNOLOGY
CONVENTIONAL
IMPROVED
 well ventilated place
STACKS LOOSE OR PERFORATED BAGS
STACK HEIGHT 1.5 M
AREATION SPACE ALL AROUND
SUITABLE CULTIVER – DM, PUNGENCY, SKIN COLOR,
SKIN NUMBER, NATURAL DORMENCY.
USE OF HYDRAZIDE AS SPROUT SUPRESSURE.
WEIGHT LOSS AROUND 35 % ON 90 DAYS STORAGE
ROTTING INCREASES WITH HUMIDITY
SPROTING INCREASES WITH TEMPERATURE
STORAGE AT 0 DEG C CAN GO FOR 150 DAYS WITH
AROUND 14 % WEIGHT LOSS
CAN BE STORED AT 30 TO 35 DEG C

44. CONTD …….STORAGE TECHNOLOGY
CONTROLLED ATMOSPHERE (CA) 3-5 % O2 + 10
% CO2, TEMP 4.4 DEG C
O2 1 % + NIL CO2 AT ROOM TEMP ALSO
SUITABLE
TRADITIONAL STRUCTURES INDIAN
TEMP: 25 – 30 DEG C, RH : 65 – 75 %
DIRECTION : NORTH – WEST
LENGTH FACING : EAST – WEST
GROUND CLEARANCE : 60 CM
STRUCTURE HEIGHT : 90 – 150 CM
FLOOR AREA FOR 25 TONNES : 4.5 X 6.0 SQ M
STR. WIDTH : 1- 1.5 M
SHADE OVER HUNG : 1.5 M

45. TYPES OF STORAGE TECHNOLOGY
IN INDIA

46. ON STRING : Strings are
tied on bulbs neck and
arranged spirally on the
rope. The ropes are hung
on poles arranged
horizontally or vertically in
the shed.

47. SINGLE POLE STORAGE METHOS
WOODEN POLES 100 – 150 MM DIA 3 – 4 M LONG
ARE ERECTED IN SHADE IN SQUARE
CINFIGURATION OF 60 – 75 CM. FULLY CURED
ONIONS ARE BUNCHED WITH LEAVES. THESE
BUNCHES ARE TIED ON POLES SPIRALLY. ONIONS
REMAIN HUNG ON POLES WITH EACH BULB
EXPOSED TO OUTER AIR.

48. HANGING METHOD: Fully
cured de - topped onions ,
packed in woven bags
hung on wooden poles
with strings
PATTARAI
CONTD …… ONION STORAGE

49. SIKA DETOPPED ONION
BUNCHED IN WOVEN NET
AND HUNG ON THE
WOODEN POLES IN SHADE
CONCENTRIC RING
SPLIT BAMBOO
100 TO 800 KG CAPACITY.
ONIONS ARE FILLED IN
BETWEEN THE RINGS.
AERATION FROM BOTTOM
AND SIDES. PLW IS
MINIMUM.

50. TRADITIONAL
SINGLE TIER
BRICK PILLERS COVERED WITH ACC
ROOF. SIDES ARE MADE OF SPLIT
BAMBOO. ONIONS STORED IN SINGLE
TIER . STACK HEIGHT 1.5 M TO 2 M.
VENTILATION THROUGH WINDOW
WALLS. PLW AROUND 30 – 50 %.
TRADITIONAL TWO
TIER
BRICK PILLERS COVERED WITH
ACC ROOF. SIDES ARE MADE OF
SPLIT BAMBOO. ONIONS
STORED IN TWO TIERS.STACK
HEIGHT 1.5 M AT GROUND AND 2
M AT FIRST FLOOR.

51. WIND TURBINE AIR
VENTILATED
ENERGY LESS NATURAL WIND
POWERED TURBINES
INSTALLED AT THE TOP SUCKS
WARM AIR FROM THE STORE.
AIR VENTS ARE KEPT AT FLOOR.
FORCED AIR
VENTILATED
PLW 5 – 10 %

52. NASIK TYPE
WOODEN OR IRON FRAME,,
WALLS AND PARTITIONS
MADE OF BAMBOO . TOTAL
LOSS AROUND 21 %.
PANI PAT TYPE 4 TONNES CAPACITY , LENGTH -
6.5 M, WIDTH – 1.5 M, SIDE
HEIGHT 1.5 M AND CENTRE
HEIGHT – 2M .LOSSES WERE
AROUND 15 %.

53. PERFORATED
CONCENTRIC
LOSSES
8 – 10 %
LOW COST- 3
TONNES
MADE OF WOODEN POLES AND SPLIT
BAMBOO 45 CM ABOVE G.L.3.6 x 1.5
x 1.5 x 2.1 M LENGTH, WIDTH, SIDE
HEIGHT, CENTRE HEIGHT. PLW – 13 %,
ROTTING- 14 % , SPROUTING – 3 %.

54. RAISED BED IMPROVED- 3
TONNES CAPACITY
MADE OF WOODEN POLES
AND SPLIT BAMBOO 3.6 x 1.5
x 1.5 x 2.1 M LENGTH, WIDTH,
SIDE HEIGHT, CENTRE
HEIGHT. PLW – 13 %,
ROTTING- 8 % , SPROUTING –
3 %.
WIRE MESH
TOTAL LOSS 35 %

55. THATCH ROOF
STORAGE 3 TONNE
CAPACITY
FRAME OF WOODEN POLES,
WALLS AND FLOOR BY SPLIT
BAMBOO, 3.6 M LENGTH, 1.5 M
WIDTH, 1.5 M SIDE HEIGHT, 2.1
M CENTRE HEIGHT, NO
VENTILATION. PLW – 15.54 %,
ROTTING LOSS – 10.22 % AND
SPROUTING LOSS 7.3 %.
DE TOPPED ONIONS ARE
STACKED ON SLATTED
FLOOR. EXHAUST FANS
ARE INSTALLED FOR
AREATION

56. DE TOPPED ONIONS PACKED
IN PERFORATED BAGS ARE
KEPT ON SLATTED FLOOR
WHERE AIR IS FORCED TO
FLOW THROUGH THE
STACKES

57. TRADITIONAL ONION STORAGE STRUCTURES WITH SINGLE DEPTH
STACK , 20 CM STACK AERATION AND 40 CM STACK AERATION

58. GRADING / SORTING : After curing and
before storage / marketing onions are graded
as less than 35 mm, 35 – 50 mm, 50 – 60 mm,
60 – 80 mm and above 80 mm bulb diameter
and sorted to fetch better price.

59. FORCED AIR ONION STORAGE

60. CONTROLLED TEMPERATURE STORAGE
STRUCTURES

61. •SPREAD ON FLOOR: Bulbs are
spread on floor in 10 – 15 cm deep
layer and turned from time to time.
The rotten / damaged and sprouted
bulbs are removed.

63. LET ONION
REACH TO ALL