12. STATISTICAL METHODS FORVALIDITY OF TEST RESULTS

D. P. SINGH &:P.K. AGRA IVi\!.

The application of an appropriate statistical method to test the results of seed

testing enables the analyst (0 determine the validity oflhe result. For seed quality

determination, the replicates/working samples from the same sample or different

sample are tested in one laboratory or different laboratories, green house or in

fields. It is generally observed that the test results may not be the same. 'Ibe

difference among results are compared with the non-significant permissible value

supported with the statistical evidence or calculated range of limits. In testing

results. this maximum. non-significant calculated range of limit or expected varia-tion is called "Tolerance numher" and a seric.."of such tolerance numbers is called

"Tolemnce Table". In case. the observed variation among the replicates is found

to be greater than the expected variation or tolerance number. the test results will

be regarded as "significant" and the test should be repeated till the observed

variation is equal to or less than the expected variation. Such repetition should be

done to a maximum of 4 limes. If the variation is still significant. it should be

concluded that it is due to heterogeneity of the lot.

The tolerance tables are used for testing the significance of the preciseestimates. There are two objectives in making a precise estimate. (i) to describe theseed quality attributes of a seed lot. and (ii) to decide if the estimate agrees wellenough with another estimate or a specification.

Sources of Variation

It must be recognised that some degree of variation does occur in seed testing

inspitc of the careful execution of the very best procedures. Therefore, it is

necessary to realise the possibilities of the variations. For example. experience,world-wide, has shown that variations do occur in the sampling process amongreplicates even when the recommended sampling proc'Cduresarc used. However.experience has also shown that the variation among laboratories has been greaterthan that due to random sampling variation. Thus, five sources of variations arerecognised. These are: (i) bag to bag variation, (ii) in-bag variation. (iii) working

144

sample variation, (iv) among analysts variation and (v) in-analyst variation. 'I11e

in-analyst variation is the average error of an analyst and can be thought of as the

variation in repeated analyses of the same sample by one analyst.

Typesof Error

Errors in decisions are of two types. One type of error is made when a lot is as

good as a first estimate or a specification states. but a decision is made that the lot

is not that good (producer's risk). A second type of error is made when a lot is notas good as stated but a decision is made that it is (consumer's risk).

When deciding on a probability, one should keep in mind that the lower the

probability of a type- I error, higher is the probability ora type-2 error. Forexample,

when the Yloprobability is used, fewer than 5% of the decisions to reject a seed lot

are wrong. Many of the lots arc corrccUy rejected because they are poorer than

stated in the first analysis or the specification. It is yx:, of the lots which are exacUy

equal to the first analysis or the specification which are falsely rejected.

BasicAssumptions

There are 3 statistical assumptions:

(i) The seed lot from which the sample is drawn should be relatively

homogeneous.

(ii) The sample must be drawn on a random manner from a sufficient numberof containers or locations in the lot.

(iii) Bias must be avoided in conducting tests.

Level of Significance

To1crance tables arc reproduced from Miles (1963) and ISTA (1985). The

tolerances are expressed at different levels of significance viz., 5%,2.5% and 1%.

The percent of significance is related with the strictness of the event or in other

words how much mathematical weight the analyst gives to the strictness of tests

criteria. Tbe strictness is a qualitative character and the mathematical weight is

quantitative. Hence, to quantify the weight, levc1 of significance (or probability of

occurrence) may be decided prior to the test procedure starts by a committee or a

authorised agency. However, selection ofthat significance level preferred practical

145

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view points of different properties and test situation than unique strictness. Dif-

ferent significance levels or probability statements give different strictness e.g. S%is more strict than 2.5% which is more strict than I %, etc.

For the sake of uniformity, the prescriptions in the rules have to relate to one

single level of significance per property. Keeping in view the test situations, the

appropriate level of significance (or probability) are given in the tables.

Use of Tolerance Tables

Several situations will arise in a seed testing laboratory when to1crances should

be used. For example,

(i) fe)[comparing the result of a replicated germination test within a laboratoryto determine if a re-test is needed.

(ii) for com paring the work of seed analysts within a laboratory to help evaluate

their accurateness and gain confidence in their ability.

(iii) for a seed law enforcement programme, the seed that has been labelled,

sampled and submitted for test will result in the need for applying tolerances w:hen

determining if the labelling is close enough in the test results.

(iv) under a Seeds Act, minimum limits of germination and purity are fixed

for seeds offered for sale. Thus to determine whether seed is equal or above to theprescribed minimum limit, tolerances may be used.

(v) to check the performance of the seed testing laboratories, referee test samples

are sent. Tolerance will again need to be applied to evaluate the accuracy oftheir results.

(vi) when it is difficult to assess the genetic purity of the seed lot in the

laboratory, the seeds are then tested by grow-out-test in greenhouse or in field. To

test the trueness of variety or existing deficiency and comparative deficiency with

specification, tolerances are used.

Appropriateness of Tolenmce Tables

For various seed quality attributes, appropriate tables have been included. The

analysts are advised to use these tables carefully for which the guidelines are givenin the Chart 12.1.

146

Scope and Limitations of Statistical Tables-With Examples

As per guiddiness given in the Chart 12.1, the test procedure is categorisedinto two parts, (i) non-sequential (fixed sampling) procedure and (ii) sequentialsampling procedure. The fixed sampling test results are compared with tolerancetableswhile in the sequential sampling, "accept and reject numbers" as indicated

in the tables arc used. The situations and components of their use are given withthe respective tables.

Non-sequential (fixed sampling) Test Procedure

A. Physical purity

In purity test, pure seed and inert matter are determined by weight while o:hercrop seed and weed seed are determined by number. The same tolerances are

appropriate for anyone of these four components or sum of any two or three ofthem. Samples of chaffy seeds vary more than non-chaffy seeds. Therefore, thetolerances are larger for chaffy seeds. The tolerance tables included in this partconsists of percents and number of foreign/weed seeds within a laboratory orbetween the two laboratories.

(i) Within laboratory (Table 12.11)

As a check on theaccuracy of the work within a laboratory it is often desirable

tohave two differentanalysts makea purityanalysis on thesame sample.Assumingthatthis has been doneand the puritypercentage obtainedon whole workingsampleby the two analysts were 98.15 and 97.25. Are the two results sufficiently close for

acceptance? To determine this, the two values should be averaged i.e. (98.15 +97.25)+ 2 =97.70.Thisvalueshouldbe locatedin Table12.11.In the table thevalue falls between 97.50-97.74. By reading across the Table 12.11in the column'"whole working sample", the tolerance value can be located which is 1.15

(tabulated value). The difference between two working samples was 98.15-97.25= 0.90 (observed value). Since the table permits a difference of 1.15 and the

difference observed in this example is 0.90 the results are within tolerance limitsand is acceptable.

It could also happen that the observed value is greater than the tabulated value,

therefore, the analysis is rejected and another analysis is required to be done. This

procedure can be used for any component of purity testing with whole or half

.working sample..<;;.This table is equally valid for chaffy and noncchaffy seeds.

147

(ii) Bl'tween laboratories (Table 12.12)

The same seed lot may often be tested by different seed testing laboratories.The first laboratory may find 98.15% pure seed and second may find 97.25%.

Calculatethe average,i.c. «J8.15+ 97.25)+ 2 =97.70.Enter inTable12.12Hndfind in which class 97.70 exists. ILis in 97.50-97.74. Opposite this cla.'isinterval,the tolerance permitted can be found in column 3 for non-chaJly seeds which is133 and in column 4 for chaffy seeds is 1.55.

In our example, the difference between the two laboratories is 0.90 which is

below the permitted value, hence the lot may be accepted. If the observed valuewas more than the permitted value the analysis is required to be repeated.

(iii) &. (iv) I'oreign seeds (Tables 12.13 and 12.14)

At a glance, there seems to be no remarkable difference between thestructuresof Table 12.13and Table 12.14. However, there is a difference in the situations.

Table 12.13 is to be used in deciding if two test results arc compatible i.e. twodeterminations about a lot arc made in the station or in different stations. While

Table 12.14 is used only when a second submiued sample from the same lot givesan inferior result as compared to the first result. 'Themethodof usingboth the tablesis samc.

Compatability oftest 12.13

If one determ illation gives 49 and 83 weed seeds in two samples from the same

lot. 'Ihe averageof these two is (49 + 83) + 2 ==66. Enterin Table 12.13and locate inwhich class interval 66 lies. It is in 64-69 class interval. The maximum tolerated

difference can be found opposite these values in column 2-the difference being 23.

The actual difference was 83-49 =34 which L<;!,TfCaterthan the tabulated value 23.

'l11ercfore, the results are not in tolerance limits and another purity test need to be made.

In comparing two samples, any weight can be used but both samples must be

of approximately the same weight. 'l11is table can also be used in comparing the

number of seeds of a single species or the total of two or more species.

Inferiority of results (Table 12.14)

Two samples of the same weight were examined for the first and secondestimates. ThesampIcfor the first estimate contained no weed seeds of species' A'

148

but the other sample contained 7 seeds of that species. Thus the average is (0 + 7)

+ 2 =3.5. The difference is (7-0) =7. Enter the Table 12.]4 in usual way; the

tolerance is 5. Since the difference of two samples exceeds the tolerance (5), the

second estimate is significantly greater than the first estimate. Hence, another test

is required to be conducted.

B. Germination

To]erances for germination test can be applied to the fol1owing :

(i) Percent normal seedlings.

(ii) Percent abnormal seedlings.

(iii) Percent dead secus.

(iv) Percent hard seeds.

(v) Percent freshly ungerminated seed, and

(vi) ,Sum of any combination of the above attributes.

Experience has shown that the variation among laboratories has been greater

than that due to only random sampling variation. There arc many causes of

significant differences between or among germination tests.

Replicated testsof 100 seeds each are made to give a cortect appraisal of thegermination potential of seed lots. Four replications or 400 seeds, are normally

testedI"orofficia]evaluation suchas fortheseed lawenforcement. Two replicationsarecommon with service samples. To help assure that the results are reliable, the

different replications should be within acceptable to]erance limits. The calculatedaverageof the replicates may be in decimal. In such a case, it should be rounded

to the nearest integer while locating the appropriate class interval in the tabIe.

(i) Range in germination percentage (Table 12.21)

Germination test was conducted on 4 replialtions of 100 seeds each, the results

were as follows: 90, 85, 92, 82. The average being (90 + 85 + 92 + 82)+ 4 =87.25(rounded to 87). Locate 87 in Table 12.21, column I under class interval 87-

88. Opposite this in column 3 (4 Rep.) the maximum difference permitted is 13.

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While in the example the maxim urn difference is 92-82= 1O.Therefore, the results

of the test could be accepted and reported.

Ifnumber of replications are 3 or 2. use the tolerances under column 4(3 Rep)

and column 5(2 Rep) respectively.

(ii) Cull1J>atibility oftest \~ithin laboratory (Table 12.22)

Two series of replicated testsare made on a sample. One group of replicates

averaged 841J{and the second group from same lot averaged 88%.

"l'heoverall average of both the groups was (84 + 88) + 2 =86%. Locate 86%in Table 12.22 and find out the class iQwhich 86 lies. [t is between 85-90 class,

Calculate the difference of both the sample groups i.e. 88-84 =4%. The toleranceof respect ive class in table 12.22 Col. 3 is 5 which is higher than the observed value

of 4%.I-lcnce. the average of the two tcsL<;should be reported. If the tests had notbeen within tolerance limits, at least one more test should be made.

(Hi) Between two laboratories (fables 12.23)

This table is valid [()r 400 seeds per laboratory and is used for percent normal

seedlings, abnormal seedlings, dead seeds, hard seeds, freshly ungerminated seeds

or any combination of these.

Let the sum of percentages of abnormal seedling and hard seeds in a test ofone laboratory is 32% and 20% in another laboratory. lbe average of both thelaboratories is (32+20)+ 2 =26%. LOGlte appropriate class interval in Table 12.23,Col. 2. it lies between 26-31% class interval. The difference of tests between

laboratories is 32-20 =12%. According to Table 12.23, Co1. 3. the tolerance is 9

but observed difference is 12. lhercrore, there is a significant difference betweentwo laboratories and hence one more test should be conducted.

(iv) Maximum ran~e behn'en replicates (Tablel2.24)

It is obvious from Table 12.21 that the test was based on percent germination

while Table 12.24 is used where replicates arc constituted on the basis of ap-

proximate same weight. Although both the types of tests is based on replicates but

method of testing is different.

150

Let, [or ex~mple, 100gms of seed is tested for germination into4 replic~tions.The number of seeds germin~ted 32, 39, 40,35 in 4 replicationsof approximately25 gms each. The lowest being 32 and highest 40, 'IllC range in germination is4G-32=14. Sum the number of seeds germinated in 4 replicates and read off the

m~ximum tolerated range in column 2 of Table 12.24. The maximum tolerated

range is 26 agninst the class 147-100 where the sum i.e. 32 + 39 + 40 + 35 = 152

lies. The maximum range observed (14) is less than the expected (2G). Hence Ule

results may be reported. If the range between highest and lowest among replicates

exceeds the expected range, another test should be made.

C. Seed Law Enfon'('ment

There arc two situations:

(i) Emluation of seller 's seed label : Comp~ring results of a test with seller's

seed label regarding (a) purity, (b) germination, and (c) foreign seeds (weed seeds,

other crop seeds, inert matter/fraction).

(ii) Comparison with specification: This seed could be sold without the

det~ilcd.labeling on the c()nt~iner so long as it meet certain minimum limits ofgermination and purity (as in the case of l~belled seed, 250 g or less packing). It

could be necessary to compare the test results found on a sample regarding (~)

purity, (b) germination and (c) foreign seeds with the specification.

(i) E,'aluation of seller's seed label

Illustration: Assume that ~ seed lot is sampled carrying a label or tag showing

the purity and germin~tion of the lot which is given below. The sample is tested in

the laboratory ~nd found to be slightly below the levels claimed on the label as

given below. Is the result of the test, found in the l~bor~tory, is acceptable?

Lable Percentage givenin the seed label

Percentage found

in the laboratory

Purity(Minimum)

Inertmatter (Maximum)

97.0

2.4

96.10

3.75

Othercrop seed (Maximum)

Weedseed (Maximum)

0.5

0.1

0.10

0.05

Germination(Minimum) 85.0 75.00

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The statistical methods used in testing different components is as follows forthe above illustration.

(a) 0) Physical Purity (Table 12.31) : Ibe average is, claimed on the label and

tests results. =(97.0 + %.10)/2 =%.55%. In Table 12.31. column A. the class

interval96-50- 96.99 should be selected since this range encompasses the %.55%.The tolerance limit permitted at this levelwould be 1.08 if the seed is non-chaffy,

incase of chaffy, it is 1.28. Calculate the difference of average claimed and testsresults i.e. 97.fX)-96.1O=0.90 which is less, than 1.00 (Tabulated): 'lberefore, the

purity claimed 97.0% is satishlctory.

(a) (ii) Inert matter, other crop seed, weed seed are the components of purity.

Therefore. the average of labeled and observed values are compared with table

12.31 similar to that in a(i) purity above.

(h) Germination (Table 12.32) : The method of using this table is also the

same. Average both the values i.e. (85 + 75) + 2 =80. At average germination of

80% with 4 test.,;,the tolerance in column Cis 7. The difference of two value..<;given

is 85-75 = 10. which is higher than tabulated value of 7. Therefore, the labelling

would not be considered satisfactory.

Foreign seeds (Table 12.33 and 12.36) : Foreign seeds can be tested bysequential and non-segue.ntialprocedures. For rapid and equally accurate deter-mination, sequential procedure is suggested. Tbe use ofTahle 12.33and 12.36areexaplained under Sequential Sampling Procedure.

(il) Cilmpar~ tht. results with specified limits

(a) Physical Purity (Table 12.34) : Ifthe minimum limits t()r pure seed is 95%

for non-chatTy crop but the sample of that kind upon testing was found to contain

93.80% pure seed. The question is whether it would be acceptable'! By referring

Table 12.34 colum A in the range of 95.00-95.49 it can be seen that the tolerance

permitted is 0.90. 'Iberefore, the tolerable or permissible variation is 95.00-0.90 =94.10%. But. in our test results it is 93.00 which is below the tolerance limit.

Therefore. the sample would be beyond the acceptable limit. This table can also be

used in similar way in case or weed seeds. other crop seeds and inert matter.

(b) Germination (Table 12.35) : The minimum limit established for germina-

tion is 70% of a particular non-chaffy crop and a sample of that kind was tested

152

which germinated at ()5~~ level. Woulo it he acceptable '! lfsing'nlhle 1235 column

A at the 70('~line, it can be seen th:lt tolerance in column C for a test of 4()() seeds

is7.Therefore. a sample germinates uplo70-7 =().vi! is lolcwble. In the example,

thesamplegerminateo 65% therefore the seed is acceptable.

()oTesting for genuineness of cultivur (Field and Lahomtol")'Test)

(i) Deficiency in variety: For testing genetic purity using plants. seeolingsandseedsthe tolerance tables 12.41and 12,42can be,used Iahle 12.41is used to

decide \vhether a first estimate of varietal purity is satisl~lctoryand Tahle 12.42 is

use(]to decide whether a specificat ion is met.

In each tanh:. the tolerance is for the numher of seeds/seedlings or plants. the

number required for taking ohservations is dependent on maximum permissible

otItypes which is given in Table 6.3 in Chapter 6. The Table 12.41 and 12.42 have

been revised (Miles. 1%3) to suit our requirement. I [owever. if the sample size

examined lies between the 2 numhcrs giwn in Tahlc 12.41 ;md 12.42 or more than

8000. the estimation of appropriate tolerance is needed which may he obtained hy

multiplying the conversion 1~lctor 'C' with the tolerance valuc available for the nearest

lower numher. The pnx:edure of calculating conversion 1~lctor 'C' is as follows.

Let the nearest lower numher for \vhich the tolerance is available in the tahle

is 'A'. The sample size examined is 'IV. The conversion l~lctorfor estimatingappropriatetolerance for sample size B =vA/B ='C'.

Example: Let the appropriate tolerance for sample size 560 he estimateo inTable12.41 for 9Y{ average genetic purity.

In Tahle 12.41. in the line of 9S'}{.the available tolerance forthe nearest lower

number 400 is 2.5.

Therefore. conversion factor C = v'4{j(j?:%O=O.S45

Thus, the appropriate tolerance =2.5 x 0.845 =2.1

Similar approach may he takcn if sample size is more than 8000 andfor theTable 12.42 (with specification) also.

(i) J)(jiciency in variety -Twoe.stimates :Prior to the test, the true to the variety

(T)percentagein the authentic sample may be known. if not. it must becstimateo

153

oy growing as many plants as is feasible of ~heauthentic sample of variety. T may

oe estimated oy the following equation.

T =Ill!) (N-n)/N

Unless the authentic sample of the variety is 100% pure. the stated percent

pure in the firslestimate must be adjusted as

c ~ TS/IOO

The percent found true to variety in the sample

F =100 (N-n) IN

and apparent deficiency

0 =C-F

only when D is positive.

where

T= The percent true to the variety in the authentic sample of variety.

s. = The percent pure stated in the first estimate.

c = The computed percent true to variety in the 'first'. estimate.

F= The percent found true to variety in the sample from the lot; this is also

the 'second' and the only estimate.

R = Minimum percent true to variety required by aspecification.

N = Number of piants in the sample.

n = The number of plants not true to the variety.

D = The apparent deficiency. An apparent deficiency exists when the percentage

from the "Second" analysis is less than that from the 'First' for a desirable component,

such as pure seed, or when the "Second" percentage is more than the 'First' for an

undesirable component, such as weed seed, inert matter, and other crop seed.

154

Example: Breeder seed is having 97% genetic purity (T). A lot is labeled as

95'*,pure (first estimate) (8). A sample of 410 seeds/plant (N) had 90 not true tothevariety(n).

C =TSIlOO = (97) (95)/100 = 92.2

F =100 (N-'n)/N = 100 (410-90)/410= 78.0

D =C-F = 92.2-,78.0 = 14.2

The average of C and F

(C+F)/2 =(92.2 + 78.0)/2 =85.1 rounded to 85.

Enter in Table 12.41 on the line of 85. Because the 41() lies between 400 and

800 and the tolerance for 410 is not available in the table, hence. there is need forestimation of the tolerance value.

Since the nearest lower numb<:;ris 400 for which the tolerance value isavailable,therefore, theconversion factor400/410 - 0.988. The tolerance value for

85, under the sample size 400 is 4.2. Hence the appropriate tolerance =4.2 x 0.988

=4.1. Since the deficiency 14.2 exceeds the tolerance 4.1. the lot is declaredmislabeled.

(ii) Testinga specification (Table] 2.42) : To test a specification, Table 12.42is to be used. A specification requires 95% true (R) to the variety. Out of 1230

plants from a lot (N), 100 were true to the variety (n). Therefore, F = 100 (N-n) IN

= 100 (1230-100) /1230 = 91.9

D = R-F = 95.0-91.9 = 3.1.

For sample size of 1230 plants the tolerance is not available in Table 12.42.Therefore,it should be estimated. In Table 12.42, on the line 95% and under

Column1000 (Nearest lower number for which tolerance is avail:1hle), thetoleranceis 1.1.

Thus, the conversion factor =1000/1230 = 0.902

Therefore, the appropriate tolerance =1.1 x.0.92 = 1.0.

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The ohserved deficiency 3.l is greater than the appropriate tolerance (1.0).hence the lot is not satisfactory.

Se<luential Samplin~ Procedure

1'I1Cf\~are two procedures of testing foreign seeds, (i) Sequential samplingmethod. (ii) Non-sl~quCf11ial sampling (Fixed sample size).

rn non-sequential sampling procedure. a fixed sample is examined for the test

hut in sequential test. usually 2 or more sub-samples are examined and the results

after exam ming a sub-sampk indicates whether another sub-sample should be

exam ined. As an average. less seeds are examined to reach a fin:II decision about

a lot if the analysis is sequential, and time is saved. Thcref()re, it is recommended

that usually sequential tests be made. The probability is the same whether a

sequential or a non-sequential test is made while the directions are long in

sequential hut tl1l'Yare easy td follow a step at a time.

Ihus. a sequential test is one in which additiona] testing is done because of a

result from previous test i.e. becallse a test showed an apparent deficiency - either

significant or non-signiricaill. another working sample is ex~lmined to obtainfurther evidence.

Scope and Limitations

There an: two situations under which this procedure can be used for testingseeds f()r seller's label. (i) Testing wIlh hrst Estimale~ (Ii) Testing with specif1Ca-

lion. Table 12.3.~and 12.36 arc used respectively for these two situations. Allhough

these two tables arc for these two situations. Nthough these two tables arc u.sually

used for one way test hut may also be used for two way test. two probabilities arcprovided. .

Pnlcedure

For test ing foreign seeds which include weed seeds, other crop seed. fractions

and inert maller, the expected value in a sample is calculated for the weight ofsccd

examined (G) to a step.

The average number expected in the weight of seed examined (E) is 10hecalculated hy the ~lI1alystusing the following formula: .

156

E=(~)nwhere

(j = Total numher of 'gr~lmmcs' (seed weight) examined upto the time of a

first estimaleor a :-.pecification is madc.

13= The hasc weight in 'grammes' of the first estimated or specification. It is

the weight in which N IS stated, where

n = Numhcr of seed:-.of a restricted species/foreign seeds/undesirahlc seeds in

the first estimate or allowed hy the specification.

Example I : Let 500 gm of seed (Ci) is examined f()ra first estimate. The hase

weight (B) is IOOgms. Two undesirahlc seeds are allowed in first estimate (N)

ESOO

2 I() (E " t.. ..=tOO x =, 10rlrst estimate)

Example2: Let one kg (WOO gms) ofsecd examined (see Chapter 4, Purity

analysis) fOr a specification (Ci). The hase tieing 100 gms (B) and N =2 again asinexampleI.

E 1000 -"I() (I

' .j"'

). =- XL.=.:.. .or specI IcatlOn.\00

Forconvenience and easy processing, it is advisable to constitute the relation-

shipbetweenNand B in the form of 1:13i.e. 1foreign seed is permissihle out of B

gmsof seed.In thisway E hecomesdirectlyproportionalto cumulativesampleweight(CSW) i.e. G. Therefore, liB will become conversion factor (CF.) for anyincreasingvalue of G hnd the process could be watched without internal mathe-

matical calculalionsfor E at each step. 'Inus E =CF x G.

Let for example 1 foreign seed is permissible (n =I) in 50 gms of seed (B),cumulativesampleweight(CSW)is 300gms(G), CF. = 1/50, E =1/50 x (j or~Y50')mOO =6. .

Similarly for G =350, 400, 450, E values are 1/50 x 350 =7; 1/50 x 4lXJ=8;1/50 x 450 = 9 and so on.

157

The procedure now starts. Table 12.33 and 12.36 have3 columns for two level<;

of significance. Column A is for number to be tested (See foot note of the table),column B is for accept number and C for reject number at 5% level of significancewhile column D and E are for 1% level of significance similar to that of Band C.

Individual or small working sample is examined and E is calculated for

observed foreign seeds/undesired seeds and results arc compared with the table

either 12.33or 12.36appropriate for the situation (i) and (ii) above. Whenever forthe first time thenumber of undesirable seeds of deficiency against the calculated

value of E is on or below the accept number (Co!. B an 0 as per situation), the testis accepted. If it is on or above the reject number (co!. C and E as per situation),the test is rejected. If it is between accept and reject number, another sample isdrawn and this process is repeated till a dccision is arrived.

Som etimes, during process, the cum u'Iative sam pIc size becomes large enough,

the procedure is' truncated'. Truncation is discontinuing the examination while the

number of foreign seed', is in-between accept and reject numbers. In case of

truncation, the decision is taken by the following procedure. If the number of

undesirable seeds is less than the mid value (half of the difference of accept the

rejeCt numbers), the lot is accepted. If the number of undesirable seeds is more than

the mid value, the lot is rejected. In this way, the mid value of accept and rejectnumbers is treated as "Tolerance number'.

(i) Testing with First Estimate (Table 12.33)

The process is started with individuals or small working samples. Count the

foreign seeds and compare this observed number with number of suitable classobtained with the help of calculated value of E as explained.

Let for example, the value of E lies at 0.55, the corresponding reject number

is 4 (Table 12.33 at 5%). Ifobserved number,of foreign seeds exceeds 4, the test

is rejected. The Tabl~ 12.33also reveals tqat at this class of testing (0.55),noacceptnumber is given, hence test can notbe accepted and more seed shouldbe examined

at least upto 6 points of E.

r-

Let during the process, foreign seed observed is 6 at E = 8, it is between6and

16 (the respective accept and reject numbers, Table 12.33), another sampleisexamined. If truncation is made (at E =,8), the test. can be terminated withacceptance because 6 is less than (1 + 16) + 2 =8.5 i.e. less than the mid valueof

158

range of accept the reject numbers.

(ii) Testing with specification (Table 12.36)

It is to be remembered that Table 12.33 and 12.36 are identical except thatTable 12.33 is used to test the first estimate while Table 12.36 is used for

specification.The procedure of calculating E is similar to that for first estimate.

Theexpected value, thus calculated (as per example 2 in this section) is comparedwithaccept and reject numberofsuitablc class of Table 12.36and decision is made

as explained for Table 12.33.

ObtainingReproducible Results

The importance of obtaining reproducible results in a seed testing laboratory

cannot be over emphasized. Because of the nature of seeds and their movement

from one area to another, the resul1s oftests need to be reproducible not only within

a given laboratory but between laboratories. 'Illis means that great care needs to be

exercised in the procedures used, in the corr~ct use of e<juipment and in following

the best judgement humanly possible in making various evaluations necessary in

seed testing.

Four major situations may arise which will continue to put pressure on seedtesting laboratories to assure that their results are reproducible. These include:

1. The testing of the same seed lot in different laboratories.

(a) The movement of seed from one state to another will result in differentlaboratoriestesting the same seed lot.

2. The testing of seed not in the seed certification programme but subject totheseed law.

(a) All laboratories should provide service testing of seeds. This means that

anyone who wants to submit a sample for testing may do so. After the seed hasbeen tested on such a basis and a report sent, the seedsman who has the seed for

sale may label it according to this report. Ultimately a seed inspector may draw aseedsample ofthe same lot and submit it for retesting.The officials will onlyknowwhether or not any differences obtained between the original test and the official.

test are significant if the laboratory's testing proceduresare reproducible.

.159

3. The checking of se.cd cert ifil::llion ~amrle~ lIndc.rthe seed law en forcemcnt

programme.

(a) The seed certification amrlc~ will tic tc~led to dclerminc 11Ihey meet Ihem il1lmum sl'cd cert ilkat ion standanJs that ha\'\:heen laid d()wn I()r~l.Idl'il'rd hefore

the ~eed is ofTered li)r sale a~ n:rtified ~l'ed. I lo\\'cvcr, this seed. lOO.,ilk,- ta~~;ng

may ultimately he ~uh.iccted 10 ~eed col1lrol sampling unllc:r the Seed Act and, . , . I, .

sub~equent seed testing 10evaluale thn;orreci I:lhdling (')1'Ihe\cliZi !()!.This seed

conlrol check will only he or value if the resulh in Ihl: lah6ratory afl~dependableand consistent. .

" .'

4. 'l11est~ltutory nature of ~eed ~ampling makes iles~enl ial thai tesls madc' for

seed law enforccmcnI he right and reproducihlc so thm it may he u~ed as l'vidcnccin courts of law.

i

I

I,I!'I

160

CHART 12.1Guidelines for usin~ tolerance tables

Test )rocedure, II . I

Non-sequential(Fixedsampling)sampling SequentialSamplingI I

Seed Law Enforecrnent

"'Foreign seeds include all the components of Purity Analysis except pure seed.

Note: l.In numbering tables, 12.1 series has been given for physical purity.12.2series for germinaion, 12.3 series for seed law enforcement and12.4 for genetic puriiy. .

2. Table numbers are given in parentheses.

A Physical B. Germination C. Seed Law Enforce- D. Geneticpurity ment Purity Foreign Seeds'"

(i) Within the (i) Within the (i) Comparison with (i) Deficiency (i) Sellers LabelLaboratory laboratory the Seller's in variety- 1st Estimate(12. [[) (12.21) label 2 Estimates ([2.41) (12.33)

(ii) Between lab- (ii) CompatibilitY (a) Physical (ii) Defidencyin (ii) With a tan-..... oratories of test-Repli- Purity comparision to dard (12.36)

(12.12) cations (12.22) (12.31) a standard (12.42)(iii) Foreign seeds* (12.13) (iii) Between labora- (11) Germination

within the laboratories tories(12.33) (12.32)(iv) Foreign (iv) Range among (ii) Comparison with a

seeds* (11.14) weighed repli- standard

two samples- cations (12.24) (a) Physical Purity (12.34)one laboratory (b) Germination (12.35)

Table 12.11 Tolerances for comparing duplicate working samples

from the same submitted sample for any component of

a purity sample for either chaffy or non-chaffy seeds

(Probability 5%)

Average Analysis of two half

sampes or two whole samples

Tolerances for difference between

(%)

Half working

samples

Whole working

samples

1. 2. 3. 4.

99.95-100.00

99.90-99.94

0.00-0.04

0.05-0.09

99.1'>5-99.89

99.80-99.84

0.10-0.14

0.15-0.19

99.75-99.79 .0.20-0.24

0.23 0.16

0.34 0.24

0.42 0.30

0.49 0.35

0.55 0.39

0.59 0.42

0.65 0.46

0.69 .0.49

0.74 0.52

0.76 "0.54

0.82 0.58

0.89 0.63

0.95 0.67

.1.00 0.71

1.06 0.75

1.15 0.81

1.26 0.89

1.37 0.97

1.47 1.04

1.54 1.09

1.63 1.15

1.70 1.20

1.78 1.26

99.70-99.74 0.25-0.29

99.65-99.69 0.30-0.34

99.60-99-64 ,00.35-0.39

99.55-99.59 0.40-0.44

99.50-99.54 0.45-0.49

99.40-99.49 0.50-0.59

99.30-99.39 0.60-0.69

99.20-99.29 0.70-0.79

99.10-99.19 0.80-0.89

99.00-99.09 0.90-0.99

98.75-98.99 1.00-1.24

98.50-98.74 1.25-1.49

98.25-98.49 1.50-1.74

98.00-98.24 1.75-1.99

97.75-97.99 2.00-2.24

97.50-97.74 2.2..'5-2.49

97.25-97.49 2.50-2.74

97.00-97.24 2.75-2.99

162

163

L 2. 3. 4

96.50-96.99 3.00-3.49 1.88 1.33

96.00-96.49 3.50-3.99 1.99 1.41

95.50-95.99 4.00-4.49 2.L2 1.50

95.00-95.49 4.50-4.99 2.22 1.57

94.00-94.99 5.00-5.99 2.38 1.68

93.00-93.99 6.00-6.99 2.56 1.81

92.00-92.99 7.00-7.99 2.73 1.93

91.00-91.99 8.oo-8.<)l) 2.90 2.05

90.00-90.99 9.00-9.99 3.04 2.15

88.00-89.99 10.00-11.99 3.25 2.30

86.00-87.99 12.00-13.99 3.4.<) 2.47

84.00-85.99 14.00-15.99 3.70 2.62

82.00-83.99 16.00-17.99 3.90 2.76

80.00-81.99 18.00-19.99 4.07 2.88

78.00-79.99 20.00-21.99 4.23 2.99

76.00-77.99 22.00-23.99 4.37 3.09

74.00-75.99 24.00-25.99 4.50 3.18

72.00-73.99 26.00-27.99 4.61 3.26

70.00-71.99 28.00-29.99 4.71 3.33

65.00-69.99 30.00-34.99 4.86 3.44

60.00-64.99 35.00-39.99 5.02 3.55

50.00-59.99 40.00-49.99 5.16 3.65

Table 12.12 Tolerances for any component of purity analysis, be-tween laboratories (probability 1%)

Average Analysis Tolerance

50 to 100';'1,

1.

Less than 50%

2.

Non-chaffy seeds Chaffy seeds

.3. 4.

99.95-100.00 0.00-0.04 0.J8 0.21

99.90-99.94 0.05-0JJ9 0.2,'; 0..32

99.85-99.89 0.10-0.14 0..34 0.40

99.80-99.84 0.15-0. L9 0.40 0.47

99.75-99.79 0.20-0.24 0.44 0.5.3

99.70-99.74 0.25-0.29 0.49 0.57

99.65-99.69 0..30-0..14 0.5.3 0.62

99.60-99.64 (U5-0..19 0.57 0.66

99.55-99.59 0.40-0.44 0.60 0.70

99.50-99.54 0.45-0.49 0.63 0.73

99.40-99.49 0.50-0.59 0.68 0.79

99..30-99..39 0.60-0.69 0.73 0.85

99.20-99.29 0.70-0.79 0.78 0.91

99.10-99.19 0.80-0.89 0.8.3 0.96

99.00-99.09 0.90-0.99 0.H7 1.01

98.7:=;-9H.99 1.00-1.24 0.94 1.10

98.50-98.74 L.2.'\-1.49 1.04 1.21

9R.15-98.49 1.50-1. 74 1.12 1.31

9KOO-98.24 1.75-1.99 1.20 1.40

97.75-97.99 2.00-1.24 1.26 1.47

97.50-97.74 2.2.'\-2.49 1.33 1.55

97.25-97.49 2.50-2.74 139 1.6.3

97.00-97.24 2.75-2.99 1.46 1.70

96.50-96.9<) 3.00-.3.49 1.54 1.80

96.00-96.49 3.50-.3.lJ9 1.64 1.92

164

.165

1. 2. 3. 4

95.50-95.99 4.00-4.49 1.74 2.04;

9:;:00-95.49 4.50-4.99 1.83 2.15

94.00-94.99 5.00-5.99 1.95 2.29

93.00-93.99 6.00-6.99 2.10 2.46

92.00-92.99 7.00-7.99 2.23 2.62

91.00-91.99 8.00-8.99 2.36 2.76

90.00-90.99 9.00-9.99 2.48 2.92

88.00-89.99 10.00-11.99 2.65 3.11

86.00-87.99 12.00-13.99 2.85 3.35

84.00-85.99 14.00-15.99 3.02 3.55

82.00-83.99 16.00-17.99 3.18 3.74

80.00-81.99 18.00-19.99 3.32 3.90

78.00-79.99 20.00-21.99 3.45 4.05

76.00-77.99 22.00-2..'3.99 3.56 4.19

74.00-75.99 24.00-2..').99 3.67 4.31

72.00-73.99 26.00-27.99 3.76 4.42

70.00-71.99 28.00-29.99 3.84 4.51

65.00-69.99 30.00-34.99 3.97 4.66

60.00-64.99 35.00-39.99 4.10 4.82

50.00-59.99 40.00-49.99 4.21 4.95

Table 12.13 Tolerances to test whether 2 estimates of number of

weed seeds or other crop seeds or inert matter are

significantly different. Both samples are of same weight(Probability 5%)

166

Avcrae Maximum Ave,rage Maximum Average Maximumof 2 tolerated of2 tolerated of2 tolerated

estimates ifference estimates difference estimates difference

3 5 76-81 25 253-264 45

4 6 82-88 26 265-276 46

5-6 7 89-95 27 277-288 47

7-8 8 ' 96-102 28 289-300 48

9-10 9 103-110 29 301-313 49

11-13 10 111-117 30 314-326 50

14-15 11 118-125 31 327-339 51

16-18 12 126-133 32 340-353 52

19-22 13 134-142 33 354-366 53

23-25 14 143-151 34 367-380 54

26-29 15 152-160 35 381-394 55

30-33 16 161-169 36 395-409 56-

34-37 17 170-178 37 410-424 57

38-42 II? 179-188 38 425-439 58

43-47 19 189-198 39 440-454 59

48-52 20 199-209 40 455-469 60

53-57 21 210-219 41 470-485 61

58-63 22 220-230 42 486-501 62

64-69 23 231-241 43 '502-518 63

70-75, 24 242-252 44 519-534 64

Table 12.14 Tolerances for counts of other seeds. This table is to be

used when other seeds l;1avebeen determined by num-

ber as prescribed in chapter 'purity analysis'. The twosamples in which counts were made must have been ofapproximately the same weight. Average counts are

given in column I, and the appropriate tolerance incolumn 2 (Probability 5%)

167

Average Tolerance Average Tolerance Average Tolerance

count count count

2 1 2 1 2

3-4 5 80-87 22 263-276 39

5-6 6 88-95 23 277-290 40

7-8 7 96-104 24 291-305 41

9-11 8 105-113 25 306-320 42

12-14 9 114-122 26 321-336 43

15-17 10 123-131 27 337-351 44

18-21 11 132-141 28 352-367 45

22-25 12 142-152 29 368-386 46

26-30 13 153-162 30 387-403 47"

31-34 14 163-173 31 404-420 48

35-40 15 174-186 32 421-438 49

41-45 . 16 187-198 33 439-456 50

46-52 17 199-210 34 457-474 51

53-58 18 211-223 35 475-493 52

59-65 19 224-235 36 494-513 53

.66-72 20 236c249 37 514-532 54

73-79 21 250-262 38 533-552 55

,

Table12.21 Maximum tolerated rclD~es germination percent fordeciding whether to retest: alh)wing for random sam.plill2 variation only (I)rohability 2.5%)

168

No. replicates of 100 seeds

Average percent germination

4 rep 3 rep 2 rep

1. 2 3 4 5

99 2 "5 4

98 3 6 5

97 4 7 6 5

96 5 8 7 6

95 6 9 X 7

93 to 94 7t08 10 9 8

91 to 92 9 to 10 it 10 9

89 to 90 11 to 12 12 II 10

87 to 88 13 to 14 13 12 11

84 to 86 15 to 17 14 13 11

81 to 83 18 1020 15" 14 2

78 to 80 21 to 23 16 15 13

77 14 17 15 13

73 to 76 25 1028 17 16 14

71 to 72 29 to "O 18 16 14

67 to 70 .111034 18 17 15

64 to 66 35 to 37 19 t7 15

56 to 63 38 \0 45 19 IX 15

5110 55 46 to 50 20 18 16

Table 12.22 Tolerance tor deciding whether tests are compatible:

allowing for random sampling variation only. 400 seeds

Wrobability 2.5%)

Average per cent germination Tolerance

2 3

98 to 99

95 to 97

2 to 3 2

91 to 94

85 to 90

4 to 6

7 to to

3

4

77 to 84

60 to 76

11 to 16

17 to 24

5

6

251041 7

51 to 59 42 1050 8

169

Table 12.23 Tolerance for comparing tests between laboratories

for germination per cent. 400 seeds per laboratory

(probability 5%)

Average percent

Tolerance

More than 50% 50% or less

1 2 3

99

97 to 98

94 to 96

2 2

3 to 4 3

45 to 7

91 to 93

87 to 90

8 io 10 5

82 to 86

76 to 81

11 to 14

is to 19

6

7

8

9

10

11

70 to 75

60 to 69

20 to 25

26 to 31

51 to 59

32 to 41

42 to 50

170

171

Table 12.24 Maximum tolerated range between replicates

(Probability 5%)

Numberof seeds Number of seeds

germinated in the Maximum germinated in the Maximum

totalweight of seed range total weight of rangetested seed tested

0-6 4 161-174 27

7-10 6 175-188 28

11-14 8 189-202 29

15-18 9 203-216 30

19-22 11 217-230 31

23-26 12 23F244 32

27-30 13 245-256 33

31-38 14 257-270 34

39-50 15 271-288 35

51-56 16 289-302 36

57-62 17 303-321 37

63-70 18 322-338 38

71-82 19 339-358 39

83-90 20 359-378 40

91-102 21 379-402 41

103-112 22 403-420 42

113-122 :;"3 421-438 43

123-134 24 439-460 44

135-146 25 > 460 45

147-160 26

.

Table 12.31 Tolerances for comparing the result.. of a purity test

with a seller's label (Probability 5%, 1%)

172

Non-chaffyseed Chaffy seedAverage of 2 estimates

5% 1% 5% 1%

A B C 01 2 . 3 4 5 6

99.95-100.00 0.00-(1.04 0.12 0.18 0.14 0.21

99.90-99.94 0.05-0.09 0.19 0.28 0.23 0.32

99.1'5-W.R9 0.10-0.14 0.24 0.34 0.28 0.40

99.RO-99.R4 0.15-0.19 0.28 0.40 0.33 0.47

99.75-99.79 0.20-0.24 0.31 0.44 0.37 0.53

99.70-99.74 0.25-0.29 0.34 0.49 0.41 0.57

99.65-99.69 0.30-0.34 0.37 0.53 0.44 0.62

99.60-99.64 0.35-0.39 0.40 0.57 0.47 0.66

99.65-99.59 0.40-0.44 0.42 0.60 0.50 0.70

99.50-99.54 0.45-0.49 0.44 0.63 0.52 0.73

99.40-99.49 0.50-0.59 0.47 0.68 0.56 0.79

99.30-9939 0.60-0.69 0.51 0.73 0.61 0.85

99.20-99.29 0.70-0.79 0.55 0.78 0.65 0.91

99.10-99.19 0.80-0.R9 0.58 0.83 0.69 .0.96

99.00-99.(19 0.90-0.99 0.61 0.87 0.72 1.01

98.75-98.99 1.00-1.24 0.66 0.94 0.78 1.10

98.50-98.94 1.25-1.49 0.73 1.04 0.86 1.21

98.25-98.49 1.50-1.74 0.79 1.12 0.92 1.31

98.00-98.24 1.75-1.99 0.84 1.20 1.00 1.40

97.75-97.99 2.00-2.24 0.88 1.26 1.05 1.47

173

L

2 3 4 5 6

97.50-97.74 2.25-2.49 0.93 1.33 1.10 1.55

97.2..'5-97.49 2.50-2.74 0.98 1.39 1.16 1.63

97.00-97.24 2.75-2.99 1.02 1.46 1.21 1.70

96.50-9,6.99 3.00-3.49 1.08 1.54 1.2R I.O

96.00-96.49 3.;\0-3.99 U5 1.64 1.36 1.92

95.50-95.99 4.00-4.49 1.22 . 1.74 1.44 2JI4

95.00-95.49 4.50-4.99 1.28 I.K\ 1.51 2.15

94.00-94.99 5.00-5.99 1.37 1.95 1.62 2.29

93.00-93.99 6.00-6.99 1.48 2.10 1.74 l.4b

92.00-92.99 7.00-7.99 1.58 2.23 1.86 2.62

91.00-91.99 8.00-8.99 1.67 2.36 1.97 2.7()

90.00-90.99 9.00-9.99 1.76 2.48 2.<17 2.92

88.00-89.99 10.00-11.99 1.88 2.65 2.20 3.ll

86.00-87.99 12.00-13.99 2.02 2.R5 2.37 3.35

84.00-85.99 14.00-15.99 2.14 3.02 2.52 3.55

82.00-83.99 16.00-17.99 2.2..'5 3.18 2.65 3.74

80.00-81.99 18.00-19.99 2.35 3.32 2.7() 3.90

78.00-79.99 20.00-21.99 2.44 3.45 2.87 4.05

76.00-77.99 22.00-23.99 2.52 3.56 2.97 4.19

74.00-75.99 24.00-2..'5.99 2.60 3.67 3.05 4.31

72.00-73.99 26.00-27.99 2.66 3.76 3.13 4.42

70.00-71.99 28.00-29.99 2.72 3.M 3.20 451

65.00-69.99 30.00-34.99 2.81 3.97 3.30 4.66

60.00-64.99 35.00-39.99 _.90 4.10 3.41 4.82

50.00-59.99 40.00-49.99 2.98 4.21 3.50 4')5

.,

Table 12.32 Tolerance for comparing the germination found and

stated on the seller's label (Probability 5%, 1%)

Average percent 4 tests 3 tests 2 tests

germination 5% 1% 5% 1% 5% 1%

A B C D E

2 3 4 5 6 7 8

99 2 + 2 2 2 1 2

98 3 3 3 2 3 2 3

97 4 3 4 3 3 2 3

96 5 3 4 3 4 3 3

95 6 4 5 3 4 3 4

94 7 4 5 4 5 3 4

93 8 4 5 4 5 3 4

92 9 5 6 4 5 4 5

91 10 5 6 5 6 4 5

90 11 5 6 5 6 4 5

89 12 5 7 5 6 4 6

88 13 6 7 5 7 4 6

87 14 6 7 5 7 4 6

86 15 6 7 6 7 5 6

85 16 6 8 6 7 5 6

84 17 6 8 6 7 5 6

83 18 7 8 6 8 5 7

82 19 7 8 6 8 5 7

81 20 7 8 6 8 5 7

80 21 7 9 6 8 5 7

79 22 7 9 6 8 5 7

78 23 7 9 7 8 5 7

77 24 7 9 7 8 6 7

174

175

2 3' 4 5 6 ,:'7 8,.

76 25 8 9 7 9 6 8

75 26 8 9 7 9 6 8

"

74 27 8 9 7 9 6 "8

13 28 8 lO 7 9 6 8

72 29 8 lO 7 9 6 8

71 30 8 10 7 9 6 8

70 , 31 8 10 7 9 6 8

69 32 8 10 7 9 6'-' 8

68 33 8 10 7 9 6 8

67 34 8 10 8 9 6 8

66' 35 8 10 8 9 6 8

65 36 8 10 8 10 6 8

64 37 8 10 8 10 6 8

63 38 8 10 8 10 6 9

62 39 9 10 8 10 6 9

61 40 9 10 8 10 6 9

60 41 9 11 8 10 6 9

59 42 9 11 8 10 7 9

58 43 9 11 8 10 7 9

57 44 9 11 8 10 7 9

56 45 9 11 8 10 7 9

55 46 9 11 8 10 7 9

54 '47 9 11 8 10 7 9

53 48 9 11 8 10 7 9

52 49 9 11 8 10 7 9

51 50 9 11 8 10 7 9

Table 12.33 Foreign-seed numbers, to test a first estimate by a

second estimate, I-way or 2-way test. Accept and rejectnumbers

Probability

Number 5% 1-way 1% 1-wayto be 10% 2-way 2% 2-waytestedl

Accept No. Reject No. Accept No RejectNo.

A 13 C D E

0.00 - 2 - 30.05 - 2 - 3(L10 - 3 - 30.15 4 - 30.20 - 4 - 4

0.25 - 4 - 40.30 4 - 40.35 4 - 40.40 - 4 - 50.45 - 4 - 5

0.50 - 4 - 50.55 - 4 - 50.60 4 - 50.65 - 4 - 6.0.70 - 4 - 6

0.75 - 4 - 60.80 - 4 - 60.85 - 5 - 60.90 - 5 - 60.95 5 - 6

1 - 5 - 72 - 7 - 93 - <) - 114 - 10 - 13:; 12 - 15

() 0 13 - 167 0 15 - 188 L 16 - 20<) 1 18 - 21

10 2 19 0 23

176

Table12.33(Cootd.)

A B C D E

11 2 20 0 2412 3 22 0 2613 4 23 1 27

. 14 4 24 1 2915 5 26 2 30

16 6 27 '3 3117 7. 28 3 3318 7 30 4 3419 8 31 5 3620 9 32 5 37

21 10 33 6 3822 10 35 6 4023 11 36 7 4124 12 37 8 42

. 25 13 38 8 44.

26 13 40 9 4527 14 41 10 4628 15 42 11 4829 16 43 11 4930 16 44 12 50

31 17 46 13 5132 18 47 13 5333 19 48 14 5434. 20 49 15 5535 20 51 15 57

36 21 52 16 5837 22 53 17 5938 23 54 18 6139 24 55 18 6240 24 56 19 63

41 25 58 20 6442 26 59 21 6643 27 60 21 6744 28 61 22 6845 29 62 23 69

46 29 64 24 7147 . 30 65 24 7248 31 66 25 7349 32 67 26 74

177

17.8

Table 12.33 (Contd.)

A B C D E,

50 33 68 27 76!

51 34 69 27 7752 34 70 28 7853 35 72 29 7954 36 73 30 8055 37 74 30 82

56 38 75 31 8357 39 76 32 8458 39 77 33 8559 40 79 34 8760 . 41 80 34 88..

61 42 81 35 8962 43 82 36 9063 44 83 37 9164 45 84 38 9365 45 '85 38 94

66 46 87 39 9567 47 88 40 9668 48 ,.. 89 41 9769 49, 90 41 9970 50 91 42 100

71 51 92 43 10172 51 93 44 10273 52 95 45 10374 53 96 46 10575 54 97 46 106

1 Number stated in the first estimate per kilogram, per pound, per ounce, or per other

weight computed to the equivalent number in the weight of seedexamined.I( .

Table 12.34" Toleran<:esfor comparing the results of purity tests with

a specifiedminimumlimitof purity (Probability5%)

Specification % N()n-chaffyseed Chaffy seed.A B" C D

99.95-10.0.-0.0. 0..00-0..04 0..10. 0..11

99.90.-99.94 0..0.5-0..09 0..14 0.16

99.85-99.89 0..10.-0..14 0..18 0..21

99.80.-99.84 0..15-0..19 0..21 0..24

99.75-99.79 0..20.-0..24 0..23 0..27

99.70.-99.74 0..25-0..29 0..25 0..30.

99.65-99.69 0..30-0..34 0..27 0..32

99.60.-99.64 0..35-0..39 0..29 0..34

99.55-99.59 0..40.-0..44 0..30. 0..35

99.50.-99.54 0..45-0..49 0..32 0..38

99.40.-99.49 0..50.-0..59 0..34 0..41

99.30.-99.39 0..60-0..69 0...37 0..44

99.20.-99.29 0..70.-0..79 0..40. 0..47

99.10.99.19 0..80-0..89 0..42 0..50.

99.00-99.09 0..90-0..99 0..44 0..52

98.75-98.99 1.00-1.24 0..48 0..57

98.50.-98.74 1.25-1.49 0..52 0..62

98.25-98.49 1.50.-1.74 0..57 0..67

98.00-98.24 1.75-1.99 0..61 0..72

97.75-97.99 2.00-2.24 0..63 0..75

97.50.-97.74 2.2.'1-2.49 0..67 0..79

97.25-97.49 2.50.-2.74 0..70. 0..83

97.0.0.-97.24 2.75-2.99 0..73 0..86

96.50.-96.99 3.oo3.49 0..77 0..91

96.0.0.-96.49 3.50.-3.99 0..82 0..97

179

180

Table 1.2}4 (Contd.)

,A/

B C D

95.50-95.99 4.00-4.49 0.87 1.02

95JI0-95.49 4.50-4.99 0.90 1.07

94.00-94.99 5.00-5.99 0.97 1.15

93.00-93.99 6.()()-6.99 1.05 1.23

92.00-92.99 7.00-7.99 1.12 1.31

91.00-91.99 8.00-8.99 1.18 1.39

90.00-90.99 9.00-9.99 1.24 1.46

88.00-89.99 10.00-11.99 1.33 1.56

86.00-87.99 12.00-13.99 1.43 1.67

84.00-85.99 14JXI-15.99 1.51 1.78

82.00-83.99 16.00-17.99 1.59 1.87

80.00-81.99 18.00-19.99 1.66 1.95

78.00-79.99 20.00-21.99 1.73 2.03-

76JJO-77.99 22.00-23.99 -1.78 2.10

74.00-75.99 24.00-25.99 -1.84 2.16

72.00-73.99 26.00-27.99 1.88 2.21

70.00-71.99 28.00-29.99 1.92 2.26

65.00-69.99 30JI0-34.99 1.99 2.33

60.00-64.99 35.00-39.99 2.05 2.41

50.00-59.99 40.00-49.99 2.11 2.48

Table 12.35 Tolerances for comparing the results of a germination

test with a specified minimum limit of germination

(Probability 5%)

Specifiedpercent 400 500 200germmation seeds seeds seeds

A B C D E

99 2 1 1 298 3 2 1 397 4 2 1 396 5 2 2 495 . 6 3 2 4

94 7 3 2 493 8 3 2 592 9 3 2 591 10 4 2 590 11 4 3 6

89 12 4 3 688 13 4 3 687 14 4 3 686 15 5 3 785 16 5 3 7

84 17 5 3 '783 18 5 3 782 19 5 4 781 20 5 4 880 21 5 4 8

79 22 6 4 878 23 6 4 g77 24 6 4 876, 25 6 4 875 26 6 4 9

74 27 6 4 973 28 6 4 972 29 6 4 971 30 6 4 970 31 -7 5 9

69 32 7 5 1068 . 33 7 5 1067' 34 7 5 1066 35 7 5 1065 36 7 5 10

181

182

Table 12.35 (Contd.)

A B C D E

64 37 7 5 1063 38 7 5 1062 39 , 7 5 10

61 40 7 5 1060 41 7 5 10

59 42 7 5 11

58 43 7 5 11

57 44 8 5 1156 45 8 5 11

55 46 8 5 11

54 47 8 5 1153 48 8 5 11

52 49 8 5 . 11

51 50 8 5 11

Table 12.36 ]<'oreign-seed numbers, to test a specification by anestimate, I-way or 2-way test. Accept and reject num-bers

ProbabilitySpecifiednumher 5% I-way 1% I-way

. I 1eqUivaent 10%2-way 2%2-way

AcceptNo. RejectNo. AcceptNo. RejectNo.A B . C D E

0.00 - 1 - 20.05 - 1 - 20.10 - 2 - 20.15 - 2 - 20.20 - 2 - 3

0.25 - 2 - 30.30 - 2 - 30.35 - 2 - 30.40 - 3 - 30.45 - 3 - 4

0.50 - 3 - 40.55 - 3 - 40.60 - 3 - 40.65 - 3 - 40.70 - 3 - 4

0.75 . - 3 - 40.80 - 3 - 40.85 - 4 - 50.90 - 4 - 50.95 - 4 - 5

I - 4 - 52 - 6 - 73 0 7 - 94 0 9 - 105 1 10 0 12

6 1 11 0 137 2 13 1 158 3 14 1 169 3 15 2 1810 4 16 '2. 19

183

Table 12.36 (Cootd.)

A B C D E

11 5 18 3 2012 6 19 4 2213 6 20 4 23

14 7 21 5 2415 8 23 6 26

16 9 24 6 2717 10 25 7 2818 10 26 8 3019 11 27 9 3120 12 29 9 32

21 13 30 10 3322 .14 31 11 35

23 14 32 12 3624 15 33 12 37

25 16 34 13 38

26 17 36 14 40

27 18 37 15 4128 19 38 15 4229 19 39 16 43

30 20 40 17 45

31 21 42 18 46

32 22 43 19 47

33 23 44 19 48

34 24 45 20 4935 25 46 21 51

36 25 47 22 52

37 26 48 23 53

38 27 50 23 5439 28, 51 24 5540 29 52 25 56

41, 30 53 26 5842 31 54 27 5943 32 55 28 6044 32 56 28 6145 33 57 29 62

46 34 59 3,0 64

47' 35 60 31 6548 36 61 32 66

49 37 62 32 67

184

185

Table12.36 (Contd.)

A 13 C. D E

50 38 63 33 68

51 . 39 64 34 6952 39 65 35 7153 40 66 36 7254 41 67 37 7355 42 69 38 74

56 43 70 38 7557 44 71 39 7658 45 72 40 7859 46. 7.'" 41 7960 47 74 42 80

61 47 75 43 8162 48 76 44 8263 49 77 44 8364 50 79 45 8465 51 80 46 86

66 52 81 47 8767 5:1 82 41' 886K 54 8:1 49 8969 55 84 49 9070 5() 85 50 91

71 56 86 5L 9272 57 87 52 9473 58 8i-: 5.'" 9574 59 <)0 54 9675 60 9L 55 97

1Numberspet:ilied per kilogram. per pound. per ounce, or per other weight cOmputed totheequivalentnumber in the weight of seedexamined.

.,

Tahle 12.41 T."ueness tnvariet.. 2 estimates, I-way test(J)"Clhahilit. 5t;l) - J)en:ent!o.

"wrage Numher of plalll. seedlings or ecdsof2 --,_._---. --...-.

'eslim:II"' 400 son !OOO I:m :WOO 4000 8000

1 4 .5 (, 7 8

100()rO 0 0 0 0 0 0 0

Norl 1.2 O.s 0.7 0.6 0.5 0.4 0.2"

9S or 2 1.<1 1.2 1.0 .0.9 0.7 0.5 0.4

>:97 or J 1.0 1.5 \3 1.1 n.t) 0.7 0.5

9b or 4 23 1.7 \.4 I.2 \.0 0.7 0.5..

",95 01'.5 2.5 \.IJ 1.6 1.4 LI 0.1' O.Ci

:--.;')4or 6 2.X 2.1 \.X 15 1.3 0.9 0.6

\)3 or 7 3.0 2.2 \.9 \.6 1.3 \.0 0.7

IJ2or}.; 3.2'"

2.0 1.7 1.4 1.0 0:7--h'

()]or\) 3.3 2.4 2.1 1.8 1.5 1.1 0.7

"'.")() (11'10 .' 3.5 2.6 2.2 I.') 1.6 1.\ 0./0:

\) or 1 1 3.6 2.7 2.3 2.0 1.6 1.2 0./0:

s nr I 2 3.R 2.1' 2.4 2.1 1.7 1.1 O.X

K?or 13 3.9 2.9 25 ...., LX 1.3 0.9

XI>or 14 4.0 3.0 2.6 2.2 I.X U 0.9

'or 1'5 4.2 3.n 2.6 2.2 1.1' J..' 0"

:,:. nr 1I> .U .'.1 2.7 2.3 1.9 lA, 1.0

K' (\1'17 4.4 :'-2 2.1' 2.4' 2.0 1.4 1.0

x2 "I' 1X 4.5. .'.3 2.1' 2.4 2.0 1.4 1.0

! or I') 4.11 3..' 2.IJ 25 2.1 1.5 1.0

Oor 20 4.7 3.4 3.0 2.6 2.1 \.5 1.1

7IJ (II' 21 4.1' 3.5 ".0 2.6 2.1 \.5 1.1

7S or 22 4. 3.5 3.1 2.7 2.2 1.6 1.1

77 or 2' 4.') .'.C> 3.1 2.7 2.2 \.6 1.1

7(1or 24 5.0 3.6 3.1 2.7 2.2 1.6 1.1

186

187

Table J2.41 (Contd.)

2 : 4 5 6 7 H

75or 25 5.1 ?t.7 ?t.2 2.R 2.? \.6 1.1

74or 26 5.1 ?t.7 ?t.2 2.R 23 1.6 1.1

73or 27 5.2 ?t.R 33 2.R 2.?t 1.7 \.2

72or 2X 5.2 ?t.R ?t3 2.R 23 1.7 1.2

71or 29 53 ?t.R ?t3 2.R 23 1.7 \.2

70or ?to 53 ?t.9 ?t.4 2.9 2.4 1.7 1.2

, 69or?t1 5.4 ?t.9 ?t.4 2.9 2.4 1.7 1.2

68or?t2 5.4 ?t.9 ?t.4 ?t.0 2.4 1.7 1.2

67or?t?t 5.5 4.0 ?t.5 .".0 2.5 I.R 1.2

66or 34 5.5 4',0 ?t.5 3.0 2.5 1$ 1.2

65or 35 55 4.0 ?t.5 ?t.0 25 1.8 1.2

Mor?t6 5.6 4.1 ?t.5 ?t.0. 25 \.8 1.2

6.' or?t7 5.6 ' 4.1 ?t.6 3.1 25 1:8 1.3

,,62or 3R 5.7 4.1 'J.6 3.1 2.5 1.8 ,1.3

61or 39 5.7 4.1 3.6 .".1 25 \.8 1.3

60or 40 5.7 4.2 ?t.6 ..I 2.5 1.8 1.3

59or 41 5.7 4.2 ?t.6 ::U 2.5 1.8 t.3

<;Xor 42 5.X 4.2 ?t.6 .3.1 25 1.8 1.3

<;7or 43 5.X 4.2 3.7 3.2 2.6 1.9 1.3

56or 44 5.X 4.2 3.7 3.2 2.6 1.9 1.3

55or 45 5.R 4.2, 3.7 3.2 2.6 1.9 1.3

54or 46 5.R 4.3 ?t.7 ?t.2 2.6 1.9 1.3

:\3or 47 5.R 43 ?t.7 3.2 2.6 1.9 1.3

52or 4X 5.R 4.?t ?t.7 3.2 2.6 \.9 1.3

51or 49 5.X 43 ?t.7 3.2 2.6 1.9 1.3

50 5.8 4.3 3.1 3.2 2.6 1.9 1.3

. Table 12.42 Trueness t variety, I pec!ficati()n- and ,. estimate,I-way est (l»rohability"5% }-I)ercents-. -.

. ..

Average Numher of plants. seedlings or seedsof2estimmes 400 gOO 1000 B50 2000 4000 8<100

2 4 5 6 7 8

iOOor 0 0 (I 0 0 0 (I 0

99 or 1 O.g OJ) 05 0.4 0.4 0.3 0.2

98 or 2 1.2 O.g 0.7 0.6 '05 0.4 0.2

97 or 3 1.4 1.1 0.9 0.8 0.6 0.5 0.3

96 or 4 1.6 1.2 1.0 0.9 0.7 0.5 0.4

95 or:; I.g 1.3 1.I 0.9 0.8 0.6 0.4

94 or 6 2.(1 1.4 1.2 1.0 0.8 0.6 0.4

93 or 7 2.1 1.5 1.3 1.[ . 0.9 0.7 05

i)2 or H 2.2 1.6 1.4 1.2 . 1.0 0.7 0.5

91 or 9 2.4 1.7' ]5 1.3 1.1 0.8 0.5

')0 or 10 25 1.8 1.6 1.4 1.1 0.8 0.6

X9 or 11 2.6 1.9 1.6 1.4 1.I 0.8 0.6

XXor 12 2.7 2.0 1.7 1.5 1.2 0.9 0.6

87 or 13 2.1-: 2.0 1.8 1.5 1.3 0.9 0.6

X6 or 14 2.9 2.1 1.8 1.5 1.3 0.<) 0.6

H5 or 15 3.0 2.2 1.9 1.6 1.3 1.0 0.7

84 or 16 .() 2.2 1.9 1.6 1.3 1.0 0.7

83 or 17 3.] 2.3 2.0 1.7 1.4 1.0 0.7

82 or 18 3.2 23 2.1 1.H 15 1.1 0.7

HI or 19 ., 2.4 2.1 U, 1.5 1.1 0.7.'.-

80 or 20 3.3 2.4 2.1 1.8 1.5 1.1 0.7

79 or 21 .H 2.4 2.1 1.8 1.5 1.1 0.7

78 or 22 3.4 25 2.2 1.8 1.6 1.1 0.8

77 or 23 . 3.5 2.5 2.2 1.9 1.6 1.1 0.8

188

189

Tbre 12.42 ((:ol1ld.)

2 .3 4 5 6 7 8

76 or 24 35 2.6 2.2 1.9 . \,() 1.1 0.8 .

75 or 25 .3.6 2.6 2.3 2.0 \.6 \.2 0.8

74 or 26 3.6 2.7 2.3 2.0 i.() 1.2 0.8

73 or 27 3.7 2.7 2.3 2.0 1.6 1.2 0.8

72 or 28 3.7 2.7 2.3 2.0 \.6 \.2 0.8

71 or 29 .3.X 2.X 2.4 2.1 1:7 1.2 0.8

70 or 30 3.X 2.X 2.4 2.1 \.7 1.2 0.8

6901'.3\ .3.8 2.8 2.4 2.1 \.7 \.2 0.8

6S-or 32 3.X 2.9 2.4 2.1 J.7 \.2 0.8

67 or 33 .3.() 2.9 2.5 2.2 1.8 1.3 0.9

66 or .4 3.9 2.9 2.5 2.2 \.8 1.3 0.'/

65 or 35 .3.9 2.9 2.5 2.2 \.8 1.3 0.9

64 or 36 4.0 2.9 2.5 2.2 \.1' 1..1 0.9

63 or 37 4.0 3.0 2.5 2.2 LX 1.3 0.9

62 or 3X 4.0 3.0 2.5 2.2 LX U 0.9

61 or 39 4.0 3.0 2.5 2.2 LX U 0.9

60 or 40 4.0 .3.0 2.6 2.2 1.8 \.3 0.9

59 or 41 4.1 3.0 2.6 2.2 LX 1.3 0.9

58 or 42 4.1 3.0 2.6 2.2 I.X 1.3 0.9

57 or 43 4.1 3.0 2.6 2.2 \.8 1.3 0.9

56 or 44 4.1 3.0 2.6 2.2 \.X 1.3 0.9

55 or 45 4.1 3.0 2.6 2.2 1.8 1.3 0.9

54 or 46 4.1 3.0 2.6 2.2 \.8 1.3 0.9

53 or 47 4.1 3.0 2.6 2.2 1.8 1.3 0.9

52 or 48 4.1 3.0 2.6 2.2 1.8 1.3 0.9

51 or 49 4.1 3.0 2.6 2.2 1.8 J.3 0.9

50 4.1 3.0 2.(' 2.2 1.1' J.3 0.')