2. SEED SAMPLING - SeedNet

2. SEED SAMPLING
RL. AGRA w.4.L
Seed sampling is aimed at obtaining a sample of the required size and
consisting of the same components as the whole lot of seeds. The quantity of seed
tested in the laboratory is small, compared with the size of the seed lot which it is
intended to represent. No matter how accurately the laboratory work is done, the
resultscan only show thequality of the sample submitted for analysis. Consequently.
every effort must be made to ensure that the sample sent to the seed testing
laboratory accurately represents the seed lot in question. Seed Testing Laboratory
personnels are not necessarily engaged in the sampling of seeds. But, nevertheless
they should be well acquainted with the principles of seed sampling and should
also be able to guide properly the p;rsons engaged in this job.
INSTRUMENTS AND SUPPLIES REQUIRED FOR SAMPLING
1. Stick of sleeve-type trier (Bag trier)
Stick of sleeve-type trier consists of a hollow brass tube inside a closely fitting
outer shell or sleeve which has a solid pointed end. The tube and sleeve have open
slots in their walls so that when the tube is turned until the slots in the tube and
sleeve are in line, seeds can flow into the cavity of the tube, and when the tube is
given a half turn the openings are closed. "Thetubes vary in length and diameter
and are made with or without partitions for different kinds of seeds (For clovers
and other small free-flowing seeds packed in bags 762 mm trier with outside
diamete of 12.7 mm and nine slots; and for cereals, 762 mm trier with outside
diameterof 25.4 mm and six slots have been foundmoresuitable).lbis trieris used
for drawing seed samples from the seed lots packed in bags or containers.
2. Bin sampler
Bin samplers are constructed on the same principle as bag triers but are much
larger. ranging up to 1600 mm in length and 38 mm in diameter with six or nine
slots. These samplers are used for drawing samples from the lots stored in the bins.
5

3. Nobbo trier
This trier is made in different dimensions to suit various kinds of seeds. It is a
pointed tube, long enough to reach the centre of the bag, with an oval hole near the
pointed end. The total length of the instrument should be aproximately 500 mm
including a handle of about 100 mm and a point of about 60 mm leaving about 310
mm to penetrate into the bage, which should be sufficient to reach the centre of all
types of bags. For cereals the intemal diameter of the tube should be about 14 mm
but for clovers and similar seeds 10 mm is sufficient.
The Nobbo trier is suitable for sampling seed in bags but not in bulle
4. Miscellaneous supplies
This includes sample pans, bucket, stapler, sewing needles and thread, a piece
of canvas (1 m x 1 m), sealing device, sam pIe bags, replacement labels and sealing
tape (duly authenticated), hand lens, scissors, flash light and packing materials,
stationery and stamps etc. .
A kit containing large and small sampling triers and misccllimoous supplies
described above is a must for seed samplers to perform their job satisfactorily.
GENERALPIDNCWLES OF SAMPLlliG
,
1. Sampling should be carried out only by persons trained and experienced in
seed sampling and employed by the official organisations.
2. The seed lot shall be so arranged that each individual container or part of
the lot is conveniently accessible. Upon request by the sampler, the owner shall
provide full information regarding the bulking and mixing of the lot. When there
is definite evidence of heterogeneity sampling should be reduced. In case of doubt,
heterogeneity can be tested (Refer Appendix Chapter 9 ).
3. Thesize of the seed lot should also not exceed maximum seed lot size limits
prescribed in Table 2.1 subject to a tolerance of 5%.
4. When sampling is being done by hand, great care should be taken to keep
the fingers tightly closed around the seeds so that none may e.scape.Seed sampler
may request that bags be emptied or partially emptied to facilitate sampling. The
6

ags may then be refilled. Thismay be necessary since it is impossible to obtain
sampledeeper than 400 mm that is, from the lower layers in bags and bins.
I 5.Other things being equal, a large sample is more representative of a lot than
is a small sample. Moreover, if there is a choice as to whether to reduce a sample
before sending it to the laboratory, the larger quantity should be submitted.
6. The sampler should determine that all seed bags sampled are identified as
belongingto a single lot, either by a label or stencil mark on the bag.
7. The sampler must sample the minimum requisite number of bags from the
seed lot. The sampling intensity must not be less than that prescribed below.
(i) For seed lots in bags (or containers of similar capacity that are uniform in
size). The Following sampling intensity is regarded as the minimum requirements.
Up to 5 containers Sample each container and always take at least
five primary samples.
6-30 containers Sample five containers or at least one in every
three containers, whichever is the greater.
31-4OQ'containers Sample 10 containers or at least one in-every
five containers, whichever is the greater.
401 or more containers Sample 80 containers or at least one in every
seven containers, whichever is greater.
(ii) For small containers: When the seed is in small containers such as tins,
cartons, or packets'as used in the retail trade, the following procedure should be
adopted.
A 100 kg weight of seed is taken as the basic unit and the small containers are
combined to form sampling units not exceeding this weight, e.g. 20 containers of
)
5 kg, 33 containers of3 kg or 100 containers of 1 kg. For sampling purposes, each
unit is regarded as one container and the sampling intensity prescribed earlier is
applied.
(iii)Forothercontainers/processingline: When sampling seed from any other
7

~--~
kind of container or from streams of seed entering containers the following shall
be regarded as the minimum requirement.
Lot Size Number of primary samples to be taken
Up to 500 kg At least five primary samples.
501-3,000 kg One primary sample for each 300 kg, but not
less than five primary samples.
3,001-20,000 kg One primary sample for each 500 kg. but not
less than 10 primary samples.
20,001 and above One primary sample for each 700 kg, but not
less than 40 primary samples.
8. Care must be exercised in reducing composite samples. Careless splitting
of the sample cannot be expected to produce two similar portions.
9. Any seed known to have been treated with a poisonous fungicide should be
identified so that the person who subsequently may handle the sample will be
infonned of the potential hazard.
10. While taking samples from machine sewed cotton bags, a few stitches at
,oneof the top comers can be loosenlbroken and then this break can pe closed with
hand stapling device after the contents of the bag have been sampled or a self
adhesive label shall be affixed to ensure proper sealing and to avoid a tampering.
11. The weight of the sample drawn should not be less than the weight of the
submitted sample prescribed in the Table 2.1.
MEmOD OF OBTAINING PRIMARY SAMPLES
The primary samples are drawn with the aid of suitable seed triers/or by hand
in case of chaffy/non free-flowing seeds.
When the lot is in bags, the bags to be sampled should be selected at random
throughout the lot and primary samples drawn by inserting the trier gently into the
bags, pointing upwards at an angle of about 30 to the horizontal, with the hole
facing downward until it reaches the centre of the bag. The trier is then revolved
8

I
through 180, bringing the hole to nice upwards, and is withdrawn with decreasing
speed so that the quantity of seed obtained from successive locations increases
progressively from centre to the side of the bag. The seed so withdrawn is em ptied
into a seed pan/or on a piece of cl()th. While the trier is being withdrawn it should
be gently agitated sO that an even flow of seed is maintained. The sampling should
be varied from top. middle and bottom of the bags. After the trier has been removed
the point should be run across the hole a couple of limes in opposite directions to
pun the threads together and close the holc.
Closed paper bags may also be sampled in this manner. Thc hole in paper bags
however, should be closed with a self adhesive tape duly signed by the sampler.
When the lot is in bulk, or in large containers, the primary samples should be
drawn with the aid of bin sampler from random positions and depths. The vertical
insertion is more practicable. The tricr is thrust into the bag/bin/bulk in the closed
position, then opened and turned a couple of times or gently agitated to aHowit to
fillcompletely.Thereafter, it isclosed again, withdrawnand emptiedjn to a suitable
seed pan/cloth. Cme should be taken in closing the trier so that seeds are not
damaged.
In the case of chaffy seed,; that have not been rendered free flowing, the
primarysamples are drawn by hand.
When seed is packed in small. or moisture-proof containers (e.g. tins, or plastic
bags). it should, if possible. be sam pled before the seed enters the containers. When
this has not been done, a sufficient number of containers shaH be opened or pierced
for abstraction of primary samples. The sampled containers shall then be closed or
the contents transferred to new containers.
Seedsarealso sampled as it enters the containers, that is, at the time processed
seeds are being put in the containers. This can be done with the help of an automatic
device or manually. An uniform quantity of seed may be taken from the seed stream
at specified. intervals.
METHOD OF PREPARING COMPOSITE SAMPLES/SUBMITTEI>
SAMPLES
When the primary samples appear uniform they arc combined and thoroughly
mixed to form the composite sample. From composite sample. "ubmittedsamplc
9

of rcquisitc weight or more is obtained either by repecited halving or by abstracting
and subsequently combining small random portions.
HES])ATCIIOF SURMITfEH SAMI)LE
Each submitted sample should be sealed and marked in a way that establishes
connection between seed lot and the seed sample. The label should contain all the
necessary detail such as variety, class of seed, quantity in the lot, to whom it
belongs. name of producer, seed treatment, date of hmvesting and threshing, if
known, sampled by, date of sampling and the kind of tests required.
After marking the sample. it should be packed so as to preyent damage during
transit. For germination tests it should be packed prererably in cloth bag. For
detcrminat ion of moisture content it should be packed separately in moisture-proof
containers from which as much air as possible has been excluded.
Samples should be despatched by the sampler to the seed testing laboratory
without delay.
SAMPLING IN SEED TESTING LABORATORY
The seed samples received in the laboratory (submitted samples*) are required
to be reduced to obtain Working sampJes for carrying out various tests. A number
of methods arc available for obtaining Working samples.
1. Mechanicaldivider method
This method is suitable for all kinds of seeds, except the extremely chaffy
types. In this method. the sample is mechanically divided by theseed dividers (the
available lypcs arc Bocrner and Gamet Seed ~eividers). the apparatus divides a
sample passedthrough it intotwoapproximately equal parts.The submitted sample
can be mixed by passing it through the divider, recombining the two parts and'
passing the whole sample through a second timc, and similarly, a third timc, if
* When a submittcd sample smaller than prescribed weight is received in the seed laboratory
the sampler may be notified aa;ordingly and analysis withheld until sufficicnt seed is
received. However, in the case of very expensive seed, the analysis may be completed to the
extent possible and the following statement inserted on the certificate "TIlc sample submitted
weighed only and is not in aa;ordance with the size prescribed in the Rules for Seed
Testing".
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necessary. The s,lmple is redpcecJ by passing the seed thropgh repeatedly an?
removing one hall' on each occasion. "Ihis process.of successive halving is con-
tinued. until a working sample of approximately. but not less than. the required size
is obtained.
2. Randomcups method
This method is particulafly suitable rorseeds requiring a working-sample upto
1() gm provided that they arc not or extrem Iy chatTy structure, and provided that
theydo notbounce or roll (like fJrassica spp.)
In principle. six to eight small cups. or thimbles, arc placed al random on a
tray. After a preliminary mixing the seed is poured unilor/TIly,over the tray. 'Ioe
seed that fallsinto the cups is taken as the working sample.
3. ModifiedhalYin~method
The apparatus comprises or a tray into which is fitted a grid of equal sized
cubical cells. open at the top and evcry alternate one having no bottom. Arter
preliminarymixing. the seed is poured evenly over the grid in the same way as it
is poured in the random cups method. When the grid is lifted. approximately hall'
thesamplcremainson the tray. Toe submitted sample is successively halved inthis
way until a working sample approximately. but not less than, th(>rcquiredsize is
obtained.
4. Spoon method
It is permissibleto use this method only [or samples of a single small-seeded
species.A tray.spatula and a spoon with a straightedge arc required.Arter
preliminarymixing. the seed is poured evenly over the tray in the same way as it
is poured in tIlerandom cups method. The tray should not be shaken thereafter.
Withthespoon in one hand. the spatula in the other, and using both, small portions
of seed rromnot less than rive random place..')on the tray should be removed.
Sufficientportionsof seed arc taken to constitute a working sampicof approximately,but
not less than. the required size.
S. The hand halving method
This method is restricted to the following ~enera of elm ffy seeds :1\ndropo!jon,
11

Arrhcnatherum, Astreblc, Cenchrus, Chloris, Dichanthium, Stylosanthes (not
guianensis), l'risctum

SEED SAJ'V1J»LlNG" SI)ECIMEN
Label on which detailed information about the seed lot may be provided and put
in the bag.
., ".................................................................................................................
Date ,..... Sampled by ;........
Sender'sNamc ;.................................................................................
Address "
.............
, ,.............
KindofculLiver/hybrid.............................................................................................
Classofsccd , ".............
LotNumber , ....................................................
Whether treated: Yes/No
Quantityof seed in lot ,................................................
Dateof harvesting& threshing (if known) """""""""""""""""""""""""""""""
Kind of Test Required'
" ,...........
Pleasecheck: Purity, Germination, TZ, Moisture, Field Plot test,
Seed health, any other (Please name)
. Remarks : """""""""""""""""""""'"
Sampledby: "...............
...............................................................................................................................
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Signature

Table 2.1. Lot and sample weights
Maximum Minimum wt. of
wLof
seed lot Submitted Work- Work-
Crop Botanical (kg) sample ing ing
name (g) sample sample
for purity col1nlof
analysis other spe-
(g) ciesseed
(g)
2 3 4 5 6
FIELD CROI)S
Cereals
Barley Hordeum FUlgare 20,000 1000 120 1000
Paddy Ol}'za satiFa 20.000 400 40 400
Triticale X. Triticosecale
Wiltmack
20,000 lOOO 120 1000
Wheat
Millets
Triticum aestivum 20,000 1000 1.20 1000
Barnyardmillet Ecillochloa cololla 10,000 SO 8 SO
Commonmillet
(Proso millet,
Hogmillet)
Pallicum miliaceum 10,000 150 15 150
Fingermillet Eleusine coracalla 10,000 60 6 60
Italianmillet
(Fox tail millet
Setaria italica 10,000 90 9 90
Kodomillet Pmpalum
scrobiculatum
10,000 SO 8 80
Littlemillet Pall/cum sumatrellse
(P. miliare)
10,000 70 7 70
Maize lea mays 40,000 1000 900 1000
Pearl millet Pell/lisetum
americanum
10,000 150 15 150
Sorghum
Pulses
Sorghum bicolor 10,000 .900 90 900
Bengal gram Cicer arietinum 20,000 1000 1000 1000
14

2 .i 4 5 6
mack gram Vigna /11//ngo 20,000 1000 150 1000
Chkkling veKh Lathyrus salims 20,000 1000 450 1000
Cowpea Vigna unguiculata 20,000 1000 400 1000
French bean Phaseolus I'li/garis 20.000 1000 700 1000
(Raj Mash)
Green gram Vigna radial a 20,000 1000 120 WOO
Horse gram Macro/yloma 20,000 500 500 500
(Kulthi) uni/7orll/l1
Indian bean l.a/1 lab P1l11JlI1-etls 20.000 1000 500 1000
(Sem)
Kidney bean Vigna aconilifolia 20,000 750 75 750
(Moth bean)
Lentil Ifl/s culillaris 10,000 600 60 600
Pea PiSU/11 .\'a/il'u111 20,000 1000 900 1000
Pigeon pea Cajanus cajan 20,000 1000 300 1000
Oilseeds
'Castor Ricinus communis 20,000 1000 1000 1000
Groundnut Arachis hypogaea 20,000 1000 1000 1000
(pods)
Groundnut
(kernels)
Arachis hypogaca 20,000 1000 600 1000
Linseed 1.inu/11usitmissimum 10,000 300 30 300
Niger
(Ram til)
Guizolia abyssinica 10,000 150 15 150
Rapeand
Mustard
Brassica spp '" 10.000 160 16 160
Rocket sated Eruca I'esicana 10,000 40 4 40
(Tara mira) (E. salim)
Safflower Carthamus IiI/clonus 10,000 1000 180 1000
Sesame Scsamum indicum 10,000 70 7 70
Soybean Glycinc max 20,000 1000 500 1000
/Sunflower
(varieties)
JIclianillUs (//l/IUS 20,000 1000 250 1000
Sunflower lie/ianlhus all/IUS 20,000 250 125 250
I (Hybrids)
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Fibre Crops
I Cotton
varieties
(delinted)
/ Cotton
(Linted)
/ Cotton hybrids
(detinted)
i Cotton hybrids
(tinted)
.lute(paisan)
Roselle
(Mesta)
Sunnhemp
Forage Crops
Birdwood grass
(Dhaman)
Blue panic
Buffel grass.
Cluster bean
Dharaf grass
Doob
Egyptian
clover
(Berseem)
Fenugreek
(Methi)
Guinea grass
Indian clover
(Sweet clover,
Senji)
Lucerne
2
Goss)'pium spp.':'
Gossypium spp."
Gos.\ypium spp.*
. Gos.\ypium spp.*
Corchorus spp.*
Hibiscus spp.***
Crotalaria jullcea
Cellchrus setigerus
Panicum antidotale
Cenchrus ciliaris
Cyamopsis
tetragolloloba
ChrysopogOlIfulvus
CYllodondactylol1
Trifolium
alexalldrillum
Trigollella spp.
Pallicum manmum
Me/notus indica
Medicago sativa
3
20,000
20,000
20,000
20,000
10,000
10,000
10,000
20,000
10,000
10,000
20,000
10,000
10,000
10,000
10,000
10.000
10,000
10,000
16
350
1000
4 5
250
350
100
700
700
25
25 2 20
25 3 25
1000 100 1000
25
60
40
~5
100
50
35
350
25
35
10
70
70
350
1000
250
350
100
700
700
3 25
1
6
10
60
4 40
2 20
10 100
5 50
6 --

2 3 4 5 6
Marvel grass Dichmzthiul11 10,000 30 3 30
alllwlatu/11
Napier grass Pellllisetum spp. 10,000 ISO 15 150
Oat Avella saliva 20,000 1000 120 1000
Paragrass Brachia/"G l11ulica 10,000 30 3 30
Rice bean Viglla umbel/ala 10,000
(Red bean)
Setaria grass Setaria allceps 10,000 25 2 20
(Nandi grass)
Shaflal Trifolium 10,000 25 2 20
reSUpil1alUm
Stylo Stylosalltlri;s spp. 10,000 70 7 70
Sudangrass Sorghum sudallellSe 10,000 250 25 250
Teosinte Euchlaella l11exicana 20,000 1000 900 1000
Velvetbean Stizelobium spp. 20,000 500 50 500
Venezuela Melillis minutiflora 10,000 25 5 25
grass
Green Manureand Miscellaneous Crops
Dhaincha Sesballia callnabilla 20,000 900 90 900
Hemp Canllabissativa 10,000 600 60 600
Indigo Illdigofera tillctoria 20,000 600 60 600
Poppy Papaver somniferum 10,000 25 1 10
Sugarbeet Beta vulgaris 20,000 500 SO 500
Tobacco Nicotialla spp. 10,000 25 0.5 5
VEGETABLES
Cucurbits
Ashgourd Bel/il1casacaifere 20,000 700 70 700
Bittergourd Momordica clzaralltia 20,000 1000 450 WOO
Boltlegourd Lagel1ariaSlcerana
L. leucallllza
20,000 700 70 700
Chow-chow Sechium edule 40,000 250 25 250
fruits fruits
17

:2 :i 4 5 6
Cucumber Cucumis S({I{FUS 10,000 150 70 150
Indian squash l'raccil ru!/us.flSIu/osus 20.000 ]000 250 1000
Little gourLi Cocl'illia graJl(/is 10,000 250 25 - 250
'Planting stakes PI. stakcs
Long melon Cucumis me!o 10,000 150 70 1.50
Musk mclon Ci{CI,lInisme!o 1(1.000 150 70 1.50
PointeLi gourLi hic!tosalll!tcs dioica 10,000 700 70 700
Pumpkin Cucurbila mosc!ta(a 10,000 350 180 350
(Kashiphal)
Ridge gourLi I,u/lcl aculallgu/a 20.000 1000 400 1000
Snakc gourLi J'riclwsalll/1/IS anguilla 20.000 1000 250 1000
Snap mclon Cucumis me/o 1.0.000 150 70 150
Sponge gourLi LuJra cy/illdric({ 20,000 1000 250 1000
Summcr squash Cucurbjla pepo 20,000 1000 700 1000
Water mclon Citrullu.l'lallalUS 20,000 1000 250 1000
Winter squash Cucurbita maxima 20,000 1000 700 1000
Fnlit Vegetables
Brinjal Solimum mclollgella 10,000 150 15 150
Chilli Capsicum frutescclIs 10,000 150 15 150
(hotpeppcr)
Okra Abe/moschus escu /emus 20,000 1000 140 1000
RatTail
RaLiish (Mungra)
Raphmlus caudatus 1.(1.000 300 30 300
Sweet Pepper Capsicum alllluum 10,000 150 15 150
/ Tomato
Lycopersicoll 10,000 70 7 70
Iycopersicum
I Tomato Lycopersicoll 10,000 7 7 7
(Hybrids) lycopcrsicum
Bulb Crops
Garlic Allium satil'um 40,000
. Multiplier Allium ccpa var. 40.000 250 25 250
onion aggregatum Bulbs Bulbs
Onion Allium cepa 10.000. 80 80 80
18

.
Green/Leafy Vegetables
2 3 4 :) 6
Amaranth Amanzathus spp. 10,000 70 7 70
Asparagus Asparagus officinalis 20,000 1000 \00 1000
Celery Apium graveolells 10,000 25 I 10
var. dulce
Coriander Corirllldrumsativum 10,000' 400 40 400
Lettuce L{lctucasaliva 10,000 30 3 30
Parsley Petraselinum crispum 10,000 40 4 40
Parsnip PaSflltaca satil'Cl 10,000 100 10 \00
Spinach Spinacia oleracea 10,000 250 25 250
Spinach beet Bela H"gari. 20,000 500 50 500
Root Crops
Carrot Daueus earota 10,000 30 3 30
Celeriac Apium graveolens 10,000 - - -
Garden beet Beta vulgaris 20,000 500 50 500
Garden rhuberb Rheum rhapollfieum 10,000 450 45 450
Globe Cynara seolymus 20,000 WOO 120 1000
artichoke
Jerusalem
artichoke
Heliant/ws tuberosus 20,000 1000 200 1000
Radish Rapllanus sativus 10,000 300 30 300
Rat tail radish Raphanus caudatus 10,000' 300 ' 30 300
Sweetpotato Ipomoea batatas 40,000 250 25 250
roots roots roots
Tapioca Manillat esculellta 40,000 250 25 250
roots roots roots
Turnip Brassica rapa 10,000 70 7 70
Legume Vegetables
Broadbean ViC/afaba 20,000 1000 1000 1000
Fieldbean Daliehs lab lab
var. lignosus
20,000 1000 600 1000
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(For French bean, Pea, Del ichos bean and Cowpea see under legumes, and for cl uster
beans under forage crops)
Cole Cmps
Cabbacge,
Cauliflowcr,
Broccoli,
Knol-kohl, etc.
. Chinese
cabbagc
13rassica spp.
(~ll varieties)
2 3 4 :; 6
Go ben, Callavalia ellsifo17nis 20,000 500 50 500
Jck bean
Lima ben PhaseD/us hlllatus 20,000 1000 1000 1000
Scarlet runner
bean
PhaseD/us coccineus 20,000 1000 1000 1000
Sword bcan CallGt'Glia g/adiata 20,000 500 50 500
B. pekinensis
and 13.Chinensis
20
10,000 100 10 100
10,000 40 4 40