Principles of seed production in self and cross pollinated crops.

Seed Production and certification (GPB-510)

1. WELCOME

2. Prof. Rajendra Singh (Rajju Bhaiya) University,
Prayagraj
DEPARTMENT – GENETICS AND PLANT BREEDING
SUBJECT – Seed Production and Certification (GPB-510)
Submitted to: Dr. S.N. Mishra
PRSU Prayagraj
Submitted by : Mudit Pandey
Class : M.Sc.(Ag) GPB- II Semester
PRSU, Prayagraj
TOPIC – Principles of seed production in cross pollinated crops

3. Types of Principles :-
(i)Genetic :-
(A) Deterioration of varieties
1.Developmental variation
2.Mechanical mixture
3.Mutation
4.Natural Crossing
5.Minor Genetic Variation
6. Selective Influence of Diseases
7.The Techniques of the Plant Breeder
(B) Maintenance of genetic purity
(ii) Agronomic :-
1. Selection of Agro- climatic Region
2. Selection of seed plot
3. Isolation of Seed crops
4. Preparation of Land
5. Selection of variety
6. Seed treatment
7. Seed plantation
8. Farm operations
9. Harvesting of seeds
10. After harvest care

4. Genetic Principle :-
(A) Deterioration of varieties
1. Developmental Variations
 Arise when seeds are grown in:
a. Difficult environment
b. Different soil & fertility conditions
c. Different climatic conditions
d. Different photo-periods
e. Different elevations
Solution:
 Grow them in their areas of adaptation & growing season

5. 2. Mechanical mixture :-
Most important source of variety deterioration
 Take place:
a. At sowing time if more than 1 variety is sown with same drill
b. During harvesting& threshing operations.
c. Gunny bags, seed bins, elevators etc are contaminated with seeds of
other varieties.
Solution:
1. Rogue the seed fields
2. Care during seed production, harvesting, threshing & further
handling

6. 3. Mutation :-
 Not a serious factor.
 Difficult to detect minor mutations.
Solution:-
 Remove mutant plant
 Increase of true to type stock eliminate the problem.
4. Natural Crossing :-
 Most important source deterioration
 The deterioration in variety due to natural crossing occurs due to the following 3
reasons:
a. Natural crossing with undesirable type.
b. Natural crossing with diseased plant
c. Natural crossing with off-type plants

7. 5. Minor Genetic Variation:-
 Exist in the phenotypically uniform & homogenous varieties at the time of their
release.
 During later production of cycle variation lost due to selective elimination by
environment.
Solution:
 Yield trials of lines propagated from plants of
 breeder’s seed in the maintenance of self fertilized crop varieties
6. Selective Influence of Diseases :-
 New crop varieties often become susceptible to new races of diseases.
 Vegetatively propagated stocks deteriorate.
Solution:
 During seed production it is very necessary to produce disease free seeds/stocks

8. 7. The Techniques of the Plant Breeder :-
Premature release of variety
Variety testing program
Break down in male sterility
Environmental conditions
Solution:
 Careful handling and adaptation of technique

9. Maintenance of Genetic Purity During Seed Production
 Use of approved seed only in seed multiplication.
 Inspection & approval of fields prior to planting.
 Field inspection & approval of growing crops at critical stages for
verification of genetic purity, detection of mixtures, weeds and for freedom
from noxious weeds & seed borne disease Etc.
 Sampling &sealing of cleaned lots.
Providing adequate isolation to prevent contamination by natural crossing or
mechanical mixtures.
 Rouging of seed fields.
Grow out test.

10. Agronomic Principles
1. Selection of Suitable Agro-Climatic Region :-
 Variety should be adapted to photoperiod and temperature of that area.
 Moderate rainfall and humidity is good for seed production.
 Dry sunny period and moderate temperature for pollination.
 General regions with extreme summer heat & very cold winters should
be avoided for seed production.
 Ample sunshine, relatively moderate rainfall & the absence of strong
winds

11. 2. Selection of Seed Plot :-
 Seed plot should have following characters:
❖ Soil texture & fertility should be according to the requirement of
the seed crops.
❖ Should be free from volunteer plants, weed plants & other crop
plants.
❖ The soil should be comparatively free from soil- borne diseases
& insect pests.
❖ In the preceding season the same crop should have not been
grown on this land, if it is so required by seed certification
standards

12. 3. Isolation of Seed Crops :-
 Done by providing distance between seed fields&
contaminating field
 On a small scale i.e. in nucleus/breeder’s seed production the
isolation can also be provided by enclosing plants in cage by
enclosing individual flowers or by removing male flower part
and then by individual artificial pollination.
After harvesting isolation of seed produced of different
varieties is necessary to avoid mechanical contamination.

13. 4. Preparation of Land :-
➢The land for seed crop must be prepared well.
➢Good land preparation helps improved germination, good stand establishment
& destruction of potential weeds.
➢ It also aids in water management &good uniform irrigation.
5. Selection of Variety :-
➢ The variety should be adapted to agro- climatic conditions of the region.
➢ The variety should really be high yielder.
➢ The variety should posses other desirable attributes, namely disease resistance,
earliness, grain quality.

14. 6. Seed Treatments :-
Chemical seed treatment.
 Seed treatment for breaking dormancy due to hard seediness.
7. Time of Planting :-
 The seed crops should invariably be sown at their normal planting time.
 Depending upon incidences of disease & pests, some adjustments could
be made if necessary.
 At time of planting there should be sufficient soil moisture for
germination to take place.

15. Seed Rate
 Lower seed rates than usual for raising commercial crop are desirable
because they facilitate rouging operations & inspection of seed crop.
Methods of Sowing
 Row method of sowing
 Mechanical drilling can be used
 Desired amount
 Uniform depth
 Clean equipment's
 Proper distance between plant

16. Depth of Sowing
 Shallow plantation in case of small seeds
 Deep plantation in case of large seeds
 Deep plantation in dry soil
Rouging
 Itis wise to remove the whole plant and not just the flower head.
 The no. of rouging necessary will vary with the crop, cleanness of planting seed &
stage of the multiplication of the seed crop.
 Rouging in most of the field crops may be done at any of the following stages as
per needs of the seed crop:
a. Vegetative /pre-flowering stage
b. Flowering stage
c. Maturity stag

17. Pollination
 Honeybee
 Insects
 Wind and water
Weed Control
(a.) The presence of weed seeds at time of crop harvest leads to mixing of weed seeds
with crop seeds. In many instances it is difficult to remove them during the
processing of seeds.
(b.) The presence of weeds in the seed field or nearby areas may serve as host to no.
of diseases. Good & effective weed control therefore would be necessary to obtain
good seed yields & to avoid contamination

18. Disease/Insect Control :-
Management of diseases & pests in seed crops:
a. Plant only treated seed
b. Prepare & adopt appropriate schedule of spraying for effective disease
&insect control.
c. Rouging of diseased plants & ear heads from time to time also helps in checking
the further spread of diseases
Nutrition :-
 Nitrogen, phosphorous potassium & several other elements play an important
role for proper development of plants &seeds.
 Identify the nutritional requirement ofseed crops & apply adequate fertilizer

19. Irrigation
 Dried regions are more suitable for good quality, disease free seed
production in that condition irrigation is essential to obtain good seed
yields.
 Before planting & at intervals up to flowering.
 One or two irrigations beyond flowering are desirable for may seed crop
Harvesting of Seed Crops
Optimum time of harvest is when seed is fully mature
 When weather damage begun, seed is easily harvested & cleaned resulting
in minimum harvest losses

20. Methods of Harvesting
 By hand
 Maintain lot identity
 My be by machine
Drying of Seeds
 More moisture at the time of harvest
 Precautions for seed drying
a. Identity of the lots must be maintained
b. Care should be taken to ensure that mechanical mixture does not take place
c. Drying of seeds to safe moisture limits should be done rather quickly

21. Storage of Raw Seeds
 Short period Storage should be in stacks or bags kept in ordinary buildings or
god owns after sun drying.
 Filling in neat & clean bags, if old then properly treated before use.
 Proper labeling.
 The stacks of bags should be made on wooden pallets.
 Storage place should be:
a. Properly clean
b. Dry
c. Cool
d. Sprayed with malathion
e. fumigated

22. Reference :-
1.ICAR e-Learning.

23. Any Question :-

24. THANK YOU