Plants are propagated either
by sexual or asexual methods.
Propagation through seeds is
the sexual method of plant
Most crop plants produce
viable seeds which is used for
sowing and those used for
human or animal consumption
are called grains.
LET US NOW DISCUSS ON
• A seed is an embryonic plant enclosed in a protective outer covering called seed
• Seed is the ripened ovule and is the basis for the sustenance of the spermatophytes.
• The study of the seed is called as Spermology.
• A typical seed includes two basic parts:
I. an embryo
II. a seed coat.
• Embryo is the fertilized ovule or an immature plant from which a new plant will
grow under proper conditions.
• In the fruit of grains, the single monocotyledon is shield shaped and hence called
• The seed coat helps protect the embryo from mechanical injury, predators and
• Depending on its development, the seed coat is either:
i) Unitegmic seed coat: It has only one covering layer.
ii) Bitegmic seed coat: It has two coverings- testa (outer) and tegmen (inner)
5. What is QUALITY SEED??
• If the seed posses high
genetic purity and high
germination percentage and
a minimum of inert, weed
and other crop seeds and is
free from diseases, it is said
to be the quality seed.
• It is estimated that good
quality seeds can contribute
about 20-25% increase in
6. Characteristics/Attributes Of Quality Seed
It must be genetically pure:
Breeder/nucleus: 100 %
Foundation seeds: 99.5%
Certified seeds varieties: 98%
Certified hybrid seeds:95%
It should have required level of physical purity: All crops: 98%
Free form other crop seeds (number/kg)
Free from objectionable weed seeds
Free from designated diseases
High germination and vigour
Optimum moisture content
Cereals: 10-12 %
7. HOW QUALITY SEED IS THE CARRIER OF NEW
The advent of modern plant breeding methods and
biotechnological advances in seed industry plays a significant
role in developing of high yielding varieties and hybrid.
The relationship between quality seed and new technology can be
discussed in two parts:
I. Technological advancement during the development of quality
II. Technological advancement during exploring the total yield
potential of the quality seed sown.
8. I . DEVELOPMENT OF QUALITY SEED
• Physical purity of the seed can be obtained by the process of removal of inert
matters and other distinguishable varieties (O.D.V.). It can be done by the ODV test
• Genetic purity can be attained by developing true to type varieties. It can be done
by preserving the unique and desired characters of the mother seed by avoiding the
unnecessary pollination and crossing over. This led to the rise of Bagging and
character selection at the genetic level.
•Inoculation of the desired characters to the seed requires the gene transfer. For
ex. Transfer of disease resistant gene to the seed.
•For the development of the quality seed, Rhizobium inoculation is done to
increase the yield through symbiotic association with the root of the leguminous
•Determination of the moisture content requires the Moisture meter.
•Viability of the seed is known or tested by Tetrazolium Chloride test or Tz test.
•Germination test is carried in the seed laboratories to determine and label the
•Field establishment trials are also done to know the adaptability of the seed.
•Development of the pest resistancy for quality seeds also contributes to the
invention of the new technologies.
9. II. EXPLORING THE TOTAL YIELD POTENTIAL OF THE
QUALITY SEED SOWN.
Seed treatment and incubation are the techniques used to increase the
plant population by minimising the germination failure due to moisture
High Density Planting (HDP) also depends on the quality seed. This
also give rise to the technique of the Crop geometry and spacing.
Use of qualitative and improved seeds demands the extensive and
balance use of NPK fertilizer. This leads to the investigation upon the
techniques of the Integrated Plant Nutrient Management(IPNM).
Integrated Weed Management(IWM) is also a tool and technique of
realizing optimum yield potential of the seed sown.
Proper development of the irrigation system is also one of the
technologies developed to explore the optimum yield potential of the
Development of the Package of Practices(POP) lead to the realization
of the total yield potential.