1. Foundation and certified seed production of castor varieties and hybrids requires careful management of sex expression to maintain genetic purity. Isolation distances of 300m for varieties and 150-300m for hybrids are needed. 2. Production of female lines for hybrids uses either a conventional method allowing 25% male plants or a refined method removing all male plants. Multiple roguings are done to eliminate off-types. 3. Hybrid seed production plants female and male parents in a 3:1 ratio with males surrounding the field. Rouging removes off-types and reversions in females. Harvesting proceeds by first removing males and then female rows.

2. N.S.AGRICULTURAL
COLLEGE,MARKAPUR
COURSE NO : GPBR -314
COURSE TITLE : Principles Of Seed Technology
TOPIC : Foundation and certified seed production of
varieties and hybrids in castor.
Submitted to: Submitted by:
by:
Dr.V. Umesh kumar sir, B.Sirisha NAA/18-
Assistant Professor, P.Supriya NAA/18-
59,
Department of Genetics and Plant breeding. P.Mounika NAA/18-

3. SEED PRODUCTION OF
CASTOR
• Seed production in castor is
challenging due to
environmentally sensitive sex
expression in parental lines.
• Success of seed production
depends on good seed source,
isolation distance and roguing.

4. • Basic Sex expression forms in
castor:
• Monoecious: a spike with basal
1/3rd to half portion filled with
male flowers and the upper portion
female flowers;
• Pistillate: a spike with female
flowers completely;
• Interspersed Staminate flowers (ISF)
:Staminate (male) flowers
interspersed throughout the spike;
• Revertant: A pistillate spike that
reverts to monoecious in later
orders

5. • Sex expression in castor is highly influenced by environmental
conditions.
• Winter season, <30°C monthly mean temperatures, young age
of plants, high nutrition especially nitrogen promote female
flowers in different spike orders.
• Where as summer season, >32°C monthly mean temperature,
old age or late order spikes, low nutrition or nitrogen promote
male flowers in different spike orders
• Morphological characters:
• Castor has wide variation morphological characters like stem
color, bloom and capsule spines, Plant type (Normal /dwarf),
Branching (Divergent/ convergent), Shape of spikes (Conical,
cylindrical, umbrella) etc.
•

7. ISOLATION REQUIREMENT AND TIME
OF SOWING:

8. SEED PRODUCTION OF VARIETIES
OR MALE LINES:
• Spacing: 90x45 cm or 90x60 cm; Seed rate: 2-3 kg/acre
• Roguing :
• First stage (Before flower initiation < 30-45 days after
sowing): Remove the morphological deviants
• Second stage (During flowering stage i.e. 45- 65 DAS):
• Flowering of spike extends over a period of 10 to 15
days. Keep the number of nodes to primary within the
stipulated range.

9. • carry out second roguing for three to five rounds at
intervals of two to three days to avoid any possible
leftovers. Select highly pistillate or monoecious
plants with male flowers restricted to the basal two
whorls to ensure better productivity of varieties or
male lines.
• Third stage: During first picking stage i.e. 90-110 DAS,
remove off types based on capsule spiny nature.

10. SEED PRODUCTION OF CASTOR
HYBRIDS
• Castor hybrids are produced using a two line system,
female (pistillate) and male (monecious/ISF). Hybrid
seed production involves 2 stages
• 1. Foundation seed production of female and male
lines and
• 2. Certified hybrid seed production.

11. FOUNDATION SEED PRODUCTION OF
FEMALE LINES
• Two methods are followed –
• 1) Conventional method
• 2) Refined or modified method (based on the pollen source used
for seed production of female line)
• Conventional method:
• Pistillate line maintained by allowing 25% monoecious or
revertants in the female line as pollen source. It leads to low
genetic purity and high roguing in hybrid seed production plots

12. • Remove all the plants with more than three whorls of male flowers in
primary raceme and retain only 25% monoecious plants with male flowers
in 2-3 whorls.
• Identify the female plants with pistillate inflorescence with well-defined
characters and tag them with red tape.
• Examine all the monoecious plants and remove those with male flowers
beyond three whorls from the base. Count the number of female and
monoecious plants in each row and remove the monoecious plants over
and above 25%.
• Examine the tagged plants regularly for reversion to monoecious
condition in 2nd, 3rd and 4th order racemes. Remove the tag as and when
a female plant reverts to monoecious condition up to 4th sequential order
branches On maturity harvest the female plants bearing the tape .

13. • Renovated method: In renovated method 100 % plants should
be pistillate lines. Whenever a plants turn to monoecious
condition in 2nd, 3rd or 4th order racemes it should be
removed.
• As all the plants are pistillate the first flush of female flowers
do not get the pollen and they drop off and 50 - 55% of
the plants will produce interspersed staminate flowers, these
interspersed staminate flowers supply the pollen required for
self-pollination and help in fertilization.

14. • Isolation: The isolation required is 300m from other varieties and
hybrids of castor
• Field inspections: A minimum of four inspections shall be made.
• 1. The first inspection : before flowering in order to determine isolation,
volunteer plants, outcrosses, planting ratio, errors in planting, stem color,
types of leaves and other relevant factors.
• 2. The second and third inspections : during flowering to check isolation,
off-types, nature of bloom, petiole, leaves, raceme, sex expressivity,
number of nodes up to primary raceme and other relevant factors.
• 3. The fourth inspection : prior to harvesting after the seed has
attained maturity
• Harvesting: Harvest the crop when the panicles are fully mature. In
general, harvesting is done in two or three pickings.

15. CERTIFIED HYBRID SEED
PRODUCTION
• The planting ratio adopted is 3 lines of female parent and
1 line of male parent. Male lines all around the borders to
ensure continuous pollen supply and avoid contamination from
other sources.
• Commercial hybrid seed production should be taken up
during rabi season when the daily mean temperatures are
less than 32°C.
• Adjust the sowing dates of male and female parent for
proper synchronization of flowering.

17. • Isolation: Isolation required is 150m to 300 m from other
varieties and hybrids of castor
• Number of field inspection: A minimum of four inspections
shall be made as follows;
• 1. The first inspection : before flowering in order to determine
isolation, volunteer plants, outcrosses, planting ratio, errors in
planting, stem color, types of leaves and other relevant factors.
• The second and third inspections The second and third
inspections : during flowering to check isolation, off-types, nature
of bloom, petiole, leaves, raceme, sex expressivity, number of
nodes up to primary raceme and other relevant factors.

18. • The fourth inspection shall be made prior
to harvesting after the seed has attained
maturity so that true nature of the plant
can be verified.
• Spacing: 90-120 cm x 60 cm.
• Seed rate : Female line: 2-3 kg/ac, male line : 1
kg/ac.

19. • Rouging:
• 1. Remove all off-types from male and female parents.
• 2. Identify the monoecious plants in female rows before
flower initiation as well as the deviants for node number
up to primary raceme, uproot and destroy them.
• 3. Continue this process every day till all plants in female
rows commence flowering.
• 4. Rouge out male parent for variants depending on
node number up to primary raceme.
• 5. Reversion in female rows to monoecism in 3rd or 4th
order racemes should not be uprooted but nipped off.

20. • Harvesting:
• Harvest the male rows first and remove them
from the field. Then harvest the female rows
picking wise. Care should be taken to avoid
mechanical mixtures during harvesting, threshing
and
• Seed yield: Hybrid: 3-6 q/ac from female; Male: 4-5
q/acre.