Seed quality testing involves evaluating various parameters of a seed lot such as physical, physiological, genetic and storability attributes. The key tests include moisture content, physical purity analysis, germination testing, seed viability assessment using tetrazolium testing, and disease testing. Seed sampling and handling procedures are important aspects of sample management in a seed testing laboratory. The primary aim of seed testing is to provide accurate results on the quality status of seed samples submitted. This allows farmers to obtain high quality seeds suited to local growing conditions.

1. SEED
QUALITY
TESTING
DR. SHWETA TIWARI

2. What is seed quality?
Defination of seed quality
● Quality seed is defined as varietal pure with a high germination percentage, free from
disease and disease organisms, and with a proper moisture content and weight
(Santos, 2007).
● Quality seed insures good germination, rapid emergence and vigorous growth.
● Ultimately, the sum of all the parameters contributing towards better performance of
seed is termed as Seed Quality
● The quality of seed in our country is legally controlled by the Seeds Act, 1966
2

3. PARAMETRS TO ASSESS SEED QUALITY?
●Physical attributes: Number of damaged seed, inert matter, weed seed, diseased seed and near
uniform seed size, comes under physical parameters and assessed through physical purity test
●Physiological attributes: Germination percentage, seed vigour and viability assessment depict through
varied test germination test, tetrazolium test, accelerated ageing test, etc
●Genetically attributes: The other variety absence, high yielding ability, adaptability to local conditions
and tolerant towards disease, pest and other biotic stress. The test determining these quality comes under
genetic purity, cultivar purity test, etc
●Storability attributes: The storability of seed depend upon the moisture content, proper seed
treatment and temperature of the environment and the test used is moisture test through moisture metre.
3

4. What is seed testing?
Defination of seed testing: Seed testing is done to evaluate the quality attributes of
seed lot, which is to be preceed in market for sale.
4
First seed testing laboratory opened by Father of seed technology, Fedrick Nobbe at
Savang, Germany in 1869
International Seed Testing Association (ISTA) was established in 1924, with sole motive
of “Uniformity in Seed Testing”
In 1962, India became an accredited member of ISTA.
In India, the Central Seed Testing Laboratory was setup during 1961-62 in Botany
Division at the IARI, New Delhi, to analyze the quality of seed samples.
The testing of seed samples was made obligatory under the Seed Act, 1996 for the purpose
of certification and for low enforcement

5. Main Aim Behind Seed Testing?
Seed testing is an important aspect for a seed programme in India
●Planting value determination
●Test the labelled seed standards
●Drying and processing need determination
●Probable cause and problem in seed quality could be assessed
●Discrimination of seed lot for consumer’s consumption at varied basic price
THE PRIMARY AIM OF THE SEED TESTING IS TO OBTAIN ACCURATEAND REPRODUCIBLERESULTS REGARDING
THE QUALITYSTATUS OF THE SEED SAMPLES SUBMITTED TO THE SEED TESTING LABORATORIES.
SEED TESTING IS DETERMINING THE STANDARDS OF A SEED LOT VIZ. PHYSICALPURITY, MOISTURE,
GERMINATIONAND ODV THEREBY ENABLINGTHE FARMING COMMUNITYTO GET QUALITYSEEDS
.
5

6. SEED SAMPLING IS DONE
Before Moving Towards Seed testing laboratory
6
 A seed sample is obtained, which represent the seed lot
 Initially 2-4 primary sample is taken out, which are blended to form
composite sample and further the submitted sample extracted
out, which is send in laboratory for registration, office for primary
reference and to producer for secondary reference
 In laboratory working sample is separate out for varied analysis
such as purity analysis, germination test, seed health test, etc
EQUIPMENT USED:
 For drawing sample from seed lot: Triers: Stick triers and Nobbe triers
 For getting desired quantity of true to the type of sample for submission in lab: Seed
dividers: Boerner type divider (Conical divider), Soil divider (multiple slot divider) and
Gamet divider (centrifugal dividers)

7. TYPES OF SEED SAMPLE
1) Primary Sample: A small portion taken from a lot at a particular stage with object of forming
composite sample
2) Composite Sample: Combining and mixing all the primary sample taken from a lot and part of
this send to lab for test
3) Submitted sample: A composite sample is usually larger in quantity. Sample reduced in
quantity for being sent to the testing station
4) Working sample: Part taken from submitted sample in the laboratory, to subjected to quality
test as describe in the ISTA
5) Guard Sample: When send to seed laboratory the seed is divided into three parts: First part:
Send to laboratory; Second part: Send to trader; Third part: Retained in laboratory. And this
third retained part is known as Guard sample

8. TYPES OF RECIEVED BY SEED TESTING
LABORATORY
1) SERVICE SAMPLE: Sample received from farmers. The sample submitted to the central
seed laboratory or to a state laboratory for testing, the results to be used as information for
seeding, selling or labelling purposes.
2) CERTIFIED SAMPLE: Sample received from certification agency or officers. Certification
sample means a sample of seed drawn by a certification agency or by a duly authorized
representative of a certification agency established under section 8 or recognized under
section 18 of the Seed Act.
3) OFFICIAL SAMPLE: Sample received from seed inspector to ascertain that the seeds meet
minimum limit of specified quality
4) CHARGED SAMPLE: Sample received from NSC, SSC, Seed dealers, and other who are
engaged in seed trade, who want to know the seed quality of the seed lot (All test are
conducted)

9. 9
7.
6.
5.
4.
3.
2.
1.
The seed sample received
should be registered and
assign test number
To save timing for complete
testing, the working samples
are prepared for varied test
The seed sample should be
indented to moisture test
first because it can add or
loss original content due to
outside condition
Routine test are performed
such as germination, vigour,
viability ,purity, other
variety test, diseased seed
test, etc
Other crop
specific test
performed
Storage of guard
sample at least for one
year after submission
of r=quality report
Record maintenance
is done for future
tracing of data
GUIDELINE TO MANAGE SEED SAMPLE EFFICIENTLY IN
SEED TESTING LABORATORY

10. SEED TEST
I. Moisture test
II. Physical purity test
III. Germination test
IV. Seed Viability
V. Seed Vigour
VI. Diseased seed test
VII. Genetic purity test
VIII. Cultivar purity test
10

11. 11
Seed Moisture
ORTHODOX SEED:
1. Desiccation tolerant;
2. Stored the seed for long time without
lowering the viability;
3. Moisture content is 5% or low, e.g.
cereals, pulses, oil seeds etc.
RECALCITRANT SEED:
1. Desiccation sensitive;
2. They are viable only at high moisture
content (15% or more),
e.g. Coffee, mango, jack fruits etc.
Several types of moisture meter are used for the testing of available moisture in
seed, such as: Universal moisture meter, Steinlite moisture meter, Digital moisture meter,
Infra red moisture meter, Karl fisher moisture meter, Agromatic mark- II, Koster moisture
meter, 35 grain moisture meter, Cenco moisture meter, and Motomco moisture meter

12. Moisture Test
A. Drying Direct Method:
B. Low constant temperature oven method: Castor, Groundnut, cotton,
brinjal, onion, Brassica, soyabean. Dried upto 17 hours
C. High constant temperature oven method: All main crop except
above, dried up to 4 hours in maize and 2 hour in other cereals.
D. Indirect Method: Conductance types (Universal moisture meter) and
Dielectric type
M2-M3/ M2-M1 X 100
Where, M1: weight in gram of container and its cover
M2: weight in gm of container, its cover and content before drying
M3: weight in gm of container cover and content after drying

13. PHYSICAL PURITY ANALYSIS
BY NUMBER BY WEIGHT
MEASURED THROUGH PHYSICAL PURITY WORK BOARD (DIAPHANASCOPE)
SUBMITTED SAMPLE INCLUDES OTHER THAN PURE SEED
WEED SEED (WS)
OTHER CROP SEED (OCS)
OBJECTIONAL WEED SEED (OWS)
DOCKAGE OTHER SEEDS
Soil Particles
Plant parts other than seeds
Nematode Galls and
Insects
Seed of the allotted crop
with half of its original
size or without seed
coat

14. PURITY TEST
Purity (%) =
Weight of pure seed
------------------------- X 100
Total weight of working sample
It denotes the percentage of seeds (by weight)
belonging to the variety under certification. Purity of
seed is calculated on weight basis as follows:
It is the percentage of a seed sample that would produce
seedling of the variety under certification. This is also
known as utility percentage of the seed. It is the function of
purity and germination percentage of the seed sample.
The real value of seed lot is determined as follows:
REAL VALUE OF SEED
Real value of seed (%) =
Purity (%) X Germination (%)
-----------------------------
100
📌

15. Germination Test
Germination percentage could be find out = Number seedling germinated X 100
Sum of normal, abnormal and un-germinated seed
15
TOP OF PAPER (TP)
For small seeds
BETWEEN PAPER (BP)
For large seeds
SAND (S)
Pulse and gourd
Seed germination on top of one layer of
paper
Seed germination between two or more
layer of paper
Seed are placed in the moist sand are covered
with another layer of moist sand

16. 90% Maize
85% Wheat, Gram, Mustard
80% Rice, Horse gram, Niger, Sesame, True potato seed, Berseem, Lucerne
75% Pulse
70%
Cabbage, Cauliflower, Brinjal, Onion, Radish, Tomato, Castor, Groundnut, Soybean,
Sunflower
65% Cotton, Bhindi
60% Gourds, Carrot, Capsicum, Cucumber, Watermelon, Chillies
Standard Minimum Germination
Percentage

17. 17
PHYSICAL TEST
PERFORMANCE TEST
STRESS TOLERANCE
BIOCHEMICAL
TEST
A. First count
B. Speed of germination
C. Seedling growth weight
Cold test= corn
Cool germination test= cotton
Brick gravel test= cereals
Pathogen infested soil
Accelerated gravity test=
cotton
Wet/dry soil
Seed size
Physical soundness
GADA
TZ
Respiration
Mitochondria activity
Membran Integrity
Seed viability and vigour test

18. TETRA ZOLIUM TEST
Number of half seeds stained red
Viable seeds (%) = -------------------------------------------- X 100
Total number of half seeds
/
18
1) This method determines the percentage of viable seeds, which may be
expected to germinate. The chemical is 2, 3, 5-triphenyl tetrazolium
chloride or bromide, which is colourless but develop red colour when
reduced by living cell. In this method half seed containing embryo is
placed in Petri dish and covered with 1% aqueous solution of
tetrazolium chloride for 4 hours.
2) After that seeds are washed in tap water and count the number of
seeds which get red stained. The per cent of viable seeds is computed
as follows:
3) This method cannot be applied for those species that have very small
seeds and embryo

19. Method for detection
Fungal Pathogen Virus Pathogen Nematode associate
pathogen
Visual Inspection
NAOH Test
Microscopic examination
Incubation Test
Serology test
Developing Seedling
examination
Controlled environment test
Visual Inspection
Microscopic examination
Infectivity Test
Serology test
Electron Microscopy Test
Developing Seedling
examination under insect
proof chamber
Visual Inspection
Microscopic examination
ELISA
Biochemical test
Physiological test
Seed Health test

20. 20
DETERMINATION OF GENETIC PURITY
ODV TEST
OTHER DITINGUISHING
VARIETY TEST
Determine genetic purity on basis of
seed characters
GOT TEST
GROW OUT TEST
Determine genetic purity on basis of
plant morphological characters
Genetic purity refers to analysis for detecting the existence of transgenic events or undesirable
genetic varieties in seed.
GENETIC PURITY

21. 21
Varieties that are grown for seed production
should be periodically tested for genetic purity
by conducting GOT to make sure that they are
being maintained in true form. GOT test is
compulsory for hybrids produced by manual
emasculation and pollination and for testing the
purity of parental lines used in hybrid seed
production.
GROW OUT TEST

22. VERIFICATION OF CULTIVARS
1. Fluorescent test for verification of oats varieties
2. Phenol colour test
3. Sodium Hydroxide test for verification of wheat varieties
4. Verification of sorghum varieties by KOH bleach test of seed
5. Identification of red rice by KOH test
6. Peroxidase activity test in Leguminaceae
7. Verification of Melilotus sp. by cupper sulphate ammonium test
8. Amonium Fluroscent test for Festuca sp

23. “
”
“THANKS TO ALL THE PATIENT
READERS “
“A seed neither fears light nor darkness, but uses both to grow.”