3. - No matters how accurately the laboratory work is done the
result can only show the quality of the sample submitted for
- Consequently, every effort must be made to ensure that the
sample sent to the seed testing laboratory accurately
represent the seed lot in question.
- The object of sampling is to obtain a representative sample of
size suitable for the required tests .a representative sample is
one which contain the same constituents as are present in the
seed lot and in the same proportions.
4. TYPES OF SAMPLING
1) Primary sample : Each probe or handful of sample taken
either in bag or in bulk is called primary sample.
2) composite sample: all the primary samples drawn are
combined together in suitable container to form a
5. 3) submitted sample: when composite sample is
properly reduced to the required size that to be
submitted to the seed testing laboratory it Is called
submitted sample .
4) working sample : it is the reduced sample with
required weight obtained from the submitted sample
after rpeated mixing and diving with which the seed
quality tests are conducted in seed testing laboratory.
7. Sampling equipment :
Deep bin sampler :- Sampling of seed lots
from bins is done by bin
Ranging up to 1600 mm in
length and 38 mm in
8. Stick or sleeve type trier
Length of sleeve trier is
58.5 cm , with handle 11
cm , sleeve 45 cm , tip 2.5
There are 5 slots each 4.5
cm in length ,the
diameter of the tube is 1
cm and sleeve 1.2 cm .
9. Nobbe trier:-
- It was made in different
diameters , to suite various
kinds of seeds .
- The total length of the
instrument is approximately
500 mm , including a handle
about 100 mm and a point of
about 60 mm , leaving about
340 mm to penetrate tn to
10. Sampling by hand :
In certain cases and certain
species ,especially chaffy ,
non-free flowering species
,hand sampling is some times
most satisfactory method.
Example of some species in
which this method followed
is Agrostis , Agropyron etc …
11. SAMPLING IN LABORATORY
MECHANICAL DIVIDER METHOD
RANDOM CUPS METHOD
THE HAND HALVING METHOD
MINIMUM WEIGHING OF WORKING SAMPLE
15. Seed testing is the determination of the
standards of seed , physical purity ,moisture ,
germination and thereby enabling the farming
community to get quality seeds.
WHAT IS SEED TESTING ?
16. By following these objectives we can minimising the risk
of planting low quality seeds.
1) To determine their quality ,that is ,their suitability for
2) To identify seed quality problems and their probable
3) To determine the need for drying and processing and
specific procedures that should be used .
4) To determine if seed meets established quality
standards or labelling specifications .
5) To establish quality and provide a basis for price and
consumer discrimination among lots in market .
OBJECTIVES OF SEED TESTING
17. As seed testing developed , it become obvious that
cooperation between seed testing stations was
imperative for the establishment of common methods of
testing that would secure uniformity in evaluation and
test results . This need ultimately led to the foundation of
the international seed testing association in 1924.
The technical and scientific work of the associations is
carried out by fifteen special committees (Eg: committee
on seed sampling and bulking ,purity , germination
INTERNATION SEED TESTING
18. 1) To provide methods by which the quality of seed
samples can be determined accurately.
2) To relate the laboratory results , in so far as is possible ,
to planting value .
3) To complete the tests within the shortest period of
time possible , commensurate with the above mentioned
4) To perform the test in the most economical manner .
IN DEVELOPING THE RULES FOR
SEED TESTING (JUSTICE 1972)
19. 1) The physical-infrastructure and facilities should be
planned on the basis of average expected workload during
the peak season , so as to permit efficient handling of seed
samples without undue delays.
2) The kinds of tests to be carried out or likely to be carried
out ,for examples , routine tests , seed health test ,varietal
purity test etc. must be ascertained in advance for making
provision in the plan.
PLAN FOR SEED TESTING LABORATORY AND
20. 3) The selection and number of the equipment should
be such as to permit efficient handling of work.
4) The equipment must meet requisite specification .
5) The decent furnishing ,light arrangement and other
necessities should be provided so as to reduce the stain
of otherwise strenuous work.
21. SEED TESTING PROCEDURES FOR
QUALITY ASSESSMENT :-
1) receipt and registration of seed samples : - the
sample received in the laboratory should be entered
in a pre-printed register or forms and assign a test
number to be used in all analysis.
2) moisture test :- These samples after assigning the
test no , should be passed on for moisture testing
analysis with out unnecessary delay .
3 ) working sample :- after entering the sample the
next step is to prepare the work sample for various
tests , it will helps to save time.
22. 4 ) routine tests :- in the seed testing laboratory ,
germination test , purity test , test for other seeds and
moisture test are known as routine test .
5 ) other tests:- These should be carried out as per
available procedures .
6 ) storage of guard sample :- these should be stored for
analysis for one year from the date of issue of report , and
calculated to minimise any change in quality .
7 ) maintenance of record :- To serve the needs of seed
certification ,farmers and other applicants , it is essential
that records are immediately available ,there for they
should be maintained properly .
23. 1) Heterogeneity of seed
2) sampling and
PROBABLE CAUSES OF DISCREPANCIES IN
SEED TEST RESULT