This document discusses seed production methods for radish. It begins by noting India's import of radish seeds and the requirements for certified radish seeds in India. It then discusses the following key points in 3 sentences: 1) Radish is a highly cross-pollinated crop in the cruciferous family that is pollinated mainly by honey bees. Seed production requires isolation distances of 1600m for foundation seed and 1000m for certified seed to prevent cross-pollination between varieties. 2) For commercial seed production, true-to-type roots are selected and cut into stecklings which are transplanted to the field. Proper temperatures, irrigation, fertilization and weed control are required to

1. Advances in seed production of
Radish (OP)
Dr.K.Padmini,
Principal Scientist,
Division of Vegetable crops,
ICAR-IIHR,
Bangalore
kpadmini@iihr.res.in

2. Demand for radish seeds
• India imported 252.63t of radish seeds during
2007-2008 (Technical Bulletin, IIVR, 2013) . In
addition, radish roots, leaves , pods and seeds
have medicinal properties.
• The total requirement of certified seeds of radish
in India during 2012-13 for 17,03,000 kg (to
cover 1,70,300ha with seed rate of 10kg/ha and
total breeder seeds produced were 705.500kg (
ICAR-DAC AICRP-vegetables report , 2013 )

3. Varieties in Seed chain
• Only Newly released and notified varieties
should be included in seed chain (AICRP)
• Pusa Chetki Chinese Pink
• Punjab Pasand Kashi Hans (VR-2)
• Arka Nishant Kashi Shweta (IIVR-1)
• Japanese White
• Punjab Safeda

4. Radish (Raphanus sativus)
Family -Cruciferae
Highly cross-pollinated crop
• Cross Pollination – mainly by honey bees
• biennial from seed production point of view,
because in the first season when the seed is
sown, the plants form root and rosette of
leaves (vegetative stage).
• In the second season, when the roots are
planted, they produce flowering shoots,
flowers and form seed

5. Floral biology
 Inflorescence is the typical terminal raceme of the
crucifers.
 Flowers are small ,usually white.
 Sepals(four) are erect and petals (four) are clawed.
 Anthesis starts at 8 a.m. and 12 noon.
 Dehiscence generally takes place at warmer
temperature condition.
 The stigma becomes receptive two days before
(protogynous) and remains up to four days after
anthesis.

6. • The Brassicaceae (or Cruciferae) family is
characterized by a siliquose fruit and
• a four-sepaled flower, with four petals in a
cross shape and
• six stamens, including two smaller ones

7. Breeding behaviour of radish
• Radish is highly cross-pollinated due to
sporophytic system of self-incompatibility.
• It shows considerable inbreeding depression on
selfing.
• It is entomophilous.
• It is pollinated mainly by wild honey bees and
wild-flower flies.

8. Types of seed production
• The “seed to seed” and “root to root”
methods are followed.
• From the seed production point of view
• European types- the seed is produced in the
hills
• Asiatic types -produces seed freely in the
plains

9. Isolation requirements
• Radish is cross pollinated by insects, chiefly honeybees.
• Seed field should not be located too close to cover crops.
• Seed field must be away from field of other radish varieties,
fields of same varieties not confirming to varietal purity
requirement for certification.
• At least 1600 meters for foundation seed production and
1000 meter for certified seed production should be kept.

10. Contaminants Minimum Permitted (%) limits
Mother root production stage Seed production stage
Fields of other
varieties of
same species
5 5 1600 1000
Field of same
variety not
conforming to
varietal purity
requirements
for certification
and for rat tail
radish
(Raphanus
caudatus)
5 5 1600 1000
ISOLATION

11. Seed Production Growing Conditions
• Soil and Climate: The ideal soil should be light,
friable and rich in humus with good drainage
facility.
• Radish can be grown on a wide variety of
climates. Asiatic types can be grown year-
round for root purpose except during the
extremely cold months of the year.
• Sowing Season: September-October (for seed
crop)

13. • Climatic requirement For proper vegetative
growth and root development of radish, cooler or
moderate climate is best suited.
• The Asian cultivars with higher temperature
adaptation can resist heat more than the
European cultivars.
• classified into three groups: (i) Japanese or winter
radish (biennial) which produces seeds only in
temperate hills of India. These cultivars require
low temperature for flowering (only hills)

14. • (2) The second group includes summer
radishes of temperate regions (e. g. white
Icicle, Rapid red white). These cultivars are
very quick in root development and behave
like winter radishes for seed production. (hills)
• (3) The third group includes cultivars which
produce seeds freely in the plains and can
produce good seeds in the hills.. (Both)

15. TYPES
Spring radishes Winter radishes
Very common, rapid growing and quick
maturing (20-30 days)
Slow growing and late maturing (50-90
days)
Relatively small roots Large roots
Root quality deteriorate quickly and
mildly pungent
Stores better and have characteristic strong
flavour

17. Varieties
• Pusa Chetki : Developed at IARI, New Delhi.. The
cultivar sets seeds profusely in the plains.
• Pusa Himani : Developed at IARI Vegetable
Research Station, Katrain by crossing Temperate
type (Black) and Asiatic type (Japanese white).
• This cultivar is suitable for growing all the year
round in the hilly region of north India. It can be
grown successfully in spring in plains of north
India with mild climate.

18. • Pusa Rashmi : The roots are 30-45 cm long, white
with green tinge on top. It is suitable for early
sowing in cooler months, but can tolerate slightly
higher temperature.
• Japanese White : Released by IARI, New Delhi..
Suitable for growing between October-December
in plains and July-September in hills.
• Punjab Safed Developed by PAU, Ludhiana..
Roots remain edible for 10 days after attaining
full size.
• Hisar Sweti-1 : Developed at CCS HAU, Hisar.

19. Ideal temperature for Flowering
• influenced by temperature.
• Low temperature is a critical factor for flowering
which is accelerated by long photoperiod.
• In Japanese type, low temperature treatment for
longer period (about 25 to 30 days) hasten flower
bud differentiation; flower stalk development,
earlier and more uniform flowering, higher
percentage of fruit set, larger fruits and heavier
seed.

20. • Bolting and flowering of Asiatic types are more
sensitive to temperature than day length,
whereas, European types respond equally to both
factors.
• A temperature of 32°C or higher causes the
stigma to become dry and pollens fail to
germinate.
• For good quality seed production radish requires
low humid climate but
• long dry periods are not suitable.

21. Flowering stage of radish

22. Flowering stage of radish

23. Tuber formation stage

24. Radish seed pods

25. • Flowering in temperate varieties usually starts
by second fortnight of March depending on
the temperature. The pod formation begins by
second fortnight of April.
• In Asiatic varieties flowering starts by the end
of February or early March and pod formation
a month later.

26. Agronomic Practices
• Field Preparation:
• soil should be brought to good tilth.
• Seed Rate For varietal production: 1.00 kg/acre For F1
(CMS based): 600 g female and 200 g male For F1 (SIC
based): 500 g male, 500 g female for SIC SIC hybrid For F1
(SIC R): 600 g female and 200 g male
• Seed Treatment: Seed treatment should be done before
sowing with any mercurial fungicide @ 2 g/kg of seed.
• Sowing Method: Generally sowing of radish in major
growing areas is carried out by hand on the ridges or as
paired rows in beds
• Spacing For root preparation: 45-60 cm x 5-7 cm
• For seed production: 60 cm x 60cm

27. Planting ratio (for hybrids)
• For SIC system: SIC : SIC = 1:1 Mixing both the
parents in equal proportion and then growing
as OP can produce the seeds of this hybrid
type.
• A (SIC) : R = 3:1
• The seeds of SIC lines should be multiplied by
bud pollination or with the spray of 2-3%
sodium chloride at the time of flowering.

28. Critical Crop Stage for Fertilizer
Application
• 1. FYM : Apply 6-8 tons of FYM per acre prior
to seed sowing on main field.
• 2. Fertilizer (kg/acre) : N:P:K = 40:20:40
• Use full doses of P, K and half of N as based
dose. The remaining half N should be applied
in two split doses–
• one at 20 days after the seed germination and
again at root development

29. • Inter-Cultural Practices:
• Thin out the extra plants after 15 days of
sowing to maintain optimum plant population
and intercultural practices.
• The crop should be kept free from weeds

30. Critical Stages for Irrigation
• It is given as per the requirement of the crop.
• Root formation stage
• Flowering stage
• Pod setting stage
Method
• Drip irrigation and mulching saves water and weeding
Frequency - in Rabi season at an interval of 8-10 days and
in Summer season at an interval of 4-5 days

31. Growth regulator sprays
GA3 sprayed at 100ppm concentration twice, at
30days after planting of stecklings resulted in
significantly increased flowering and seed yield of
radish .
Staking
Staking is done to provide support to the tall
growing seed stalks to prevent dislodging and
higher seed yield.

32. General Seed Production Methodology
• There are two popular methods for producing
radish seed:
• 1. Seed to seed (in situ) 2. Root to seed (the
transplanting) The root to seed method gives
high quality seed as compare to the in situ
method because the transplanting method
gives an opportunity to select the desired
roots

33. Selection criteria of roots
• Selection of Roots: Uniform true-to-type desired
roots are selected.
• These roots are slant cut leaving 10 cm from the
top. The leaves are also cut leaving 8 cm attached
with the roots.
• These stecklings are treated with Bavistin powder
at the cut end before transplanting
• In OP varieties selected roots of the varieties are
cut leaving 10 cm of the root and 8 cm of leaves.

34. • Lifting and selection of roots Plants with off-type foliage
and early bolters should be removed prior to lifting of
roots.
• Fully developed roots are pulled out and true to type 30
roots are selected. The roots are observed for shape, size
and colour etc. All the under developed, deformed, forked,
diseased and off- type roots are discarded.
• Preparation of stecklings
• medium size roots are preferred to large roots. Half of the
lower portion of root and two—third upper portion of
leaves is removed. These stecklings are transplanted

35. • Field Inspection
 Mother root production stage
A minimum of two inspections shall be made as follows.
The first inspection should be made after 20 -30 days of
sowing in order to determine isolation, off-types and
other relevant factors.
The second inspection shall be made after the roots have
been lifted to verify the true characteristics of roots.
Seed production stage
A minimum of one inspection should be made during
flowering to check isolation, off types, designated and
other relevant factors.

36. Roguing and Selection
 Roguing and selection are the most important operations in
seed stage f the variety.
 Selection and roguing are done on the basis of foliage
characters, root shape, size, colour, flesh colour, pithiness,
pungency and bolting behavior after thorough examination.
 Small, deformed, diseased and other undesirable roots are
discarded.
 Hairy, forked roots and early or late bolters are also removed.
 A minimum of 3 inspections and roguing are necessary to
maintain the genetic purity of a variety.

37. Stages of roguing (Seed-to-Seed method)
• 1. At market maturity stage of radish - Root: relative size,
shape, colour, proportions of each colour on bicoloured
cultivars.
• 2. At stem elongation- Remove early bolting plants and off-
types according to stem colour. Remove wild radish types.
• Check that the remaining plants are true to type for foliage
and stem characters.
• 3. At flower bud and very early at start of anthesis- For
Flower colour which is characteristic to the variety.

38. Roguing (Root-to-Seed method)
 When the roots are fully mature, the crop is harvested and true-to-type
roots are selected.
 The selection and roguing are done on the basis of foliage characters and
root characters both external and internal (colour, shape, size, flesh
colour,core size, pungency, bolting time indistinct rings etc.).
 Diseased, misshapen, undersized, and other undesirable roots are
discarded. Hairy, forked ,early as well as late bolters are also removed.
 Then the selected roots after giving suitable root and shoot cut, are
planted at 50-90 cm distance in rows and 20 cm apart with in rows.
Undesirable roots are discarded.

39. • After selection, the plant’s leaves are twisted off (leaving the
growing point undamaged) and the radish roots are put in a
bucket of water.
• Those roots with a degree of pithiness float which are needed
to be discarded. Only the solid roots sink which are to be
retained.
• After selection of true-to-type and solid roots, their tops and
tips are cut and transplanted in a well prepared field.
• The stecklings of roots can be prepared by giving one-third
top (shoot) cut and one-fourth to one-half root cut to obtain
higher yield of better quality seeds.
• Seed multiplication ratio is 1: 100.

40. SPECIFIC REQUIREMENTS
Max permittedMax permitted at second inspection at mother root production stage.
**Max permitted after flowering and at seed production stage.
Seed borne disease to be considered shall be Black rot and Black leg
 at second inspection at mother root production stage.
**Max permitted after flowering and at seed production stage.
Seed borne disease to be considered shall be Black rot and Black leg
FactorsR Minimum Permitted (%) limits
Foundation Certified
*Roots not
conforming to the
varietal
Characteristics
including for seed
roots
0.10 0.20
**Off Types (Plants)
0.10 0.20
Plants infected by
seed borne diseases 0.10 0.50
RADISH FIELD REQURIEMENTS
MaMAond inspection at mother root production stage.
**Max permitted after flowering and at seed production stage.
Seed borne disease to be considered shall be Black rot and Black leg

41. Harvesting and threshing
• The crop is cut when plants are fully matured.
• Crop is cut with sickle and brought to threshing
floor for threshing.
• There is more often difficulty in threshing the
seeds from pods.
• The pod does not break easily to allow the seed
to be shattered

42. • It is therefore, important to thoroughly dry them
before commencing the threshing.
• Radish pod do not dehisce even after maturity.
• Threshing can be done by beating with the sticks.
• Seeds afterwards should be dried to 6 per cent
moisture before storage.

43. • First roguing is carried out at vegetative stage
i. e. about a month after sowing off-type plants
on the basis of foliage characters are removed.
• The second when roots are lifted and replanted
• the third at flowering on the basis of flower
colour. All early and late flowering plants and
plants having different colour flowers are
removed. All weeds especially wild radish, wild
turnip, wild mustard and plants of other crops/
variety should also be removed to avoid possible
cross pollination.

44. Plant Protection
• Pests: Aphids, flea beetle, hairy carepillars and
mustard sawfly are the major insects pests
attacks the radish crop.
• Control : Spray Malathion (0.1%) or Seven (0.2%)
or Rogor 35 EC (0.1%) at 10 days interval.
• Diseases: Damping off, white rust, Alternaria
blight are the major disease affecting the crop.
• Control :seed should be treated before sowing
with Thiram or Captan @ 2 gm/kg seed and on
the occurrence of disease spray Dithane M-45 or
Blitox @ 0.2% at 15 days interval.

45. • Roguing :
• At the vegetative stage rogue out the volunteer and off
type plants from the field.
• At the time of flowering initiation rogue out the fertile
plants (from male sterile) and other types from the female
rows.
• Synchronization in the Male and Female Parents:
Synchronization in male and female parents is of immense
importance, so adjust the planting dates for proper
synchronization to get maximum yield.
• Isolation Distance From one variety/line to another
variety/line 1600m for foundation seeds and 100m for
certified seeds

46. Post-Harvest Management
• Optimum Stages of Harvesting : Harvest the crop
when 75% pods/siliques have turned yellowish.
• Radish pods are indehiscent and seed shattering
is not a problem
• Bundles of harvested plants should be stacked
and dried in the sun for few days before threshing
to extract seeds
• Threshing Methods Threshing should be done
either by using the stick or by tractor or thresher

48. Matured radish pods
Dried radish pods for seed
harvest

49. Seed yield
• The average seed yield ranges from 500 to 1000
kg/ha depending on varieties.
• Higher yields up to 1400 kg/ha can be obtained
under favourable conditions .
• Temperate varieties — 175 to 250 kg/ ha Asiatic
varieties - 400 to 600 kg/ ha
• 1000 seed weight of radish is 9-12g.

50. Field standards (specific requirements)
• Items Maximum percentage permitted
Foundation seed Certified seed
• Off-type (%) 0.10 (F) 0.20 (C)
• Seed borne diseases (%) 0.10 (F) 0.50 (C)
• Not seed borne diseases 0.50 (F) 1.00 (C)

51. Radish seed quality standards
Crop
Seed type
Pure
seed
(Min
%)
Inert
Matter
(Max)
(%)
Other
crop
seed
(Max./kg)
Weed
seed
(Max./kg)
Germinat
ion
(Min %)
Moisture
(%)(Max)
Normal
Vapour
proof
container
(max)
Foundation
seed
98.0 2.0 5 10 70 6.0 5.0
Certified
seed
98.0 2.0 10 20 70 6.0 5.0

52. Storage
The seeds after sifting should be dried to 6-8 percent
moisture content before storage which is very
essential to preserve seed viability and vigour.
 Air screen cleaners are used to clean and grade the
seeds. Seed after grading should contain minimum of
98% pure seed with at least 70% germinability.
Higher seed viability can be maintained when
stored in moisture impervious container at 5°C and -
20°C storage.

53. Seeds stored in moisture semi-impermeable
containers possess fairly high viability (79%) at 5°C
storage, while seeds are succumbed to chilling
injury when stored in moisture permeable
containers.
Generally, when kept in cold storage at 7°C and
less than 40% humidity , radish could be stored for
5 years without loss of seed viability in moisture
proof bags.

54. Maintenance of Inbred/Pure Lines
 Due to existence of self-incompatibility in radish,
selfing can be accomplished by bud pollination.
The flower buds should be pollinated 2 days prior
to their opening by their own pollen from
previously bagged flowers of the same plant
when the plant has about 30 percent flowering
than just at the commencement of flowering.

55. Seed Storage
• The moisture contents of the seed should be
less than 6% at the time of storage.
• Radish seed can be stored under normal
conditions

56. Seed Standards
• Class of seed F –Foundation C-Certified seed
• Items (%)
• Pure seed (minimum) 98.00 (F) 97.00 (C)
• Inert matter (maximum) 2.00 (F) 3.00 (C)
• Other crop seeds (maximum) 0.05 (F) 0.10 (C)
• Germination (minimum) 70.00(F) 60.00 (C)
• Moisture content (maximum)
• i) Ordinary container 6.00(F) 6.00 (C)
• ii) Vapour proof container 5.00 (F) 5.00 (C)

58. Thanks