This document summarizes India's three-tier system of silkworm seed multiplication. It discusses the three levels - P3, P2, and P1 stations. P3 stations maintain pure breeds under strict hygienic conditions. 20% of P3 cocoons are selected and sent to P2 stations. P2 stations also maintain pure breeds and send 25% of cocoons to P1 stations. P1 stations conduct hybridization and distribute 25% of cocoons to seed rearers and grainagers. The system helps produce quality seeds in adequate quantities and maintain genetic purity across multiplication levels.

1. By,
Nayana, B. P.
Msc. (Agri.)
SRF
UAHS, Shivamogga

2. Three Tier – System of Silkworm Seed
Multiplication
 To produce quality silkworm seed in adequate quantity
during suitable brushing period, several multiplication
levels are needed.
 In India, the Sericulture producing states are maintaining
a 3 – tier seed multiplication system and it is more
systematic in Karnataka state.
 During the grainage operation one must know the seed
suitability for a particular area before releasing the seed
commercially.

3. A particular race is suitable to a particular area.
Therefore such basic stocks are to be
maintained at P3 stations.
The P3 stations are those stations where highly
scientific and hygienic conditions are
maintained at every movement of seed
maintenance.
The 3 tier seed multiplication system is
essential to maintain the quality and vitality of
seed cocoons, which depends on vigor of the
parent stock races.

4. 1. P3 Station:- (Great Grand Parent Station)
The basic stocks are maintained at P3 stations which
are the center for germplasm banks for many races.
In P3 stations, the pure races are reared totally on
scientific lines under highly hygienic conditions.
These P3 stations are also called the Great
Grandparent stations.
Usually, these stations are under the control of the
Research institutes or State Governments.

5. P3 rearings are conducted in cellular method of
rearing.
During the rearing period of foreign races (Pure
breeds), suitable climatic conditions are maintained
since even small fluctuation in temperature or
humidity cannot be tolerated by the pure breeds.
Hence, it is essential not only to maintain optimum
climatic conditions but also separate cellular
batches.

6.  At each stage of larval development microscopic
examination is extremely important.
 Each laying is reared separately by skilled technicians on
the utmost scientific lines up to the cocoons.
 The P3 stations are generally located at places where
climate is suitable for bivoltine rearing.
 Where bivoltine rearing is conducted, multivoltine
rearing can also be conducted.
 The quantity of P3 brushings depends upon the
requirement of P2 seeds.
 20% of the cocoons from the P3 station are selected and
sent to P2 stations where P2 layings are prepared.

7. • While selecting 20% of the P3 cocoons, it is
essential to follow certain racial characters such as:
Cocoon size
Shape of the cocoon
Compactness of cocoon
Less floss
Weight of cocoons etc.,
• An expert can easily identify the quality of the cocoon
by visual examination

8. 2. P2 Station:- (Grand Parent Station)
 The main source of seed cocoons in the P2 station comes
from the P3 station.
 Brushing of P2 seed is calculated on the basis of the
requirement of seed at the P1 station
 The pure breeds are reared at P2 station to produce pure
breed eggs.
 During the production of pure eggs one should maintain
hygienic conditions as in the case of the P3 station and
technically qualified experts should undertake this activity.

9. Around 5 DFLS in each batch are reared
separately by the cellular method
The P2 station can also be know as the grand
parent station
These stations produced the foundation stock
seed and serve as germplasm banks
25% of the best cocoons of each laying can be
selected for dispatch to the P1 station by visual
examination.

10. 3. P1 Station:-
 The seed cocoons received from the P2 stations are reared
 The 1st hybridization of double crosses is done at these
stations
 25% of the cocoons produced are sent to the grainagers
or seed rearers.
 P1 stations send the seed cocoons to licensed seed cocoon
dealers
 The layings are distributed to selected seed rearers.

11. For this purpose selected seed areas are notified
The selected seed rearers must possess a good
knowledge of rearing the seed cocoons on
scientific lines
The seed rearer must maintain a separate
mulberry garden to rear the seed cocoons
Separate rearing houses with facilities to
maintain the climatic conditions and possessing
the required rearing equipments are the pre-
requisites
The premium price for a seed cocoon grower is
higher than that for a commercial cocoon
grower.

12. Concepts of Seed Areas / Seed Area Concept
• To produce commercial seeds, in Karnataka during 1940
they have identified seed areas. They are:
For multiplication of multivoltine races
 Kunigal
 Magadi These are recognized through legislation
 Hebbur
For bivoltine races
1. Belgaum
2. Anekal
3. K.R. Pet

13. In India
1. Phalgat – Kerala
2. Gorantla – A.P. Multivoltine seed Areas
3. Palmaner – A.P.
 The aim of this is to produce large no of seeds and
maintain purity, vigour and vitality of seeds and to
ensure uninterrupted supply of seeds to farmers
 In Karnataka, few breeding stations have been
identified. They are:

14. Pure Mysore
1. Magadi - Bangalore rural dt
2. Kunigal - Tumkur dt
3. Hebbur- Tumkur dt
3
The seed areas in Karnataka

15. Bivoltine seed areas
1. Anekal - Bangalore urban dt
2. Belgaum, Khanapur, Hukkeri, Sauadatti - Belgaum dt
3. Mudigere, Sringeri, Koppa, N.R. Pura- Chikkamagalur dt
4. Sullya - South Canara dt
5. Dharwad -Dharwad dt
6. Hassan, Alur, Belur, Sakleshpur - Hassan dt
7. Madikeri, Somawarpet, Veerajpet - Kodagu dt
8. K.R. Pet - Mandya dt
9. Shimoga, Sagar, Hosanagar, Tirthahalli, Shikaripur, Sorab -
Shimoga dt
10. Karwar, Supa, Halyal, Yellapur, Mundgod, Sirsi, Siddapur,
Kumta, Honnavara, Bhatkal- North Canara dt
35
Total: 3+35 = 38

16. Thank you