1. Sampling is done to get a uniform and representative sample from a seed lot. The size of the submitted sample required for testing is small as compared to the size of the lot, therefore, care must be taken to ensure that the submitted sample represents the lot of the seed to be tested.
2. Hence it is essential that the samples be prepared in accordance to ISTA rules to ensure that the small size sample should represent truly and in the same proportion all constituents of seed lot.

• When the primary samples appear uniform they are combined and thoroughly mixed to form the composite sample.
• From composite sample, submitted sample of requisite weight or more is obtained either by repeated halving or by abstracting and subsequently combining small random portions.

Sampling intensity

Seed Size                                Maximum quantity per lot
Larger than wheat and paddy        20,000 kg
Smaller than wheat and paddy     10,000 kg
Maize                                                  40,000 kg

Sampling intensity

The intensity of sampling should be maintained in accordance to the rules described by ISTA. When seeds are stored in bags or other containers of similar capacity that are uniform in size.

a. For seed lots in bags (or container of similar capacity that are uniform in size)
           

           up to 5 containers                    Sample each container
                                                            but never < 5 Primary Sample (PS)
            
           6-30 containers                       Sample atleast one in every 3 containers
                                                            but never> than  5 Primary Sample

           31-400 containers                  Sample atleast one in every 5 containers
                                                            but never < 10 Primary Sample Sample

           401 or more                               Sample atleast one in every 7 containers
                                                            but never < 80 Primary Sample

            When the seed is in small containers such as tins, cartons or packets a 100 kg weight is taken as the basic unit and small containers are combined to form sampling units not exceeding this weight e.g. 20 containers of 5 kg each. For sampling purpose each unit is regarded as one container.

b. For seeds in bulk

Up to - 500 kg                                Atleast 5 Primary samples

501 - 3000 Kg                               One primary sample for each 300 kg but not less than 5 primary samples

3001-20,000 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

Instructions for sending samples

Pre-requisite in sampling is that the seed lot received in containers / bags must be properly sealed and marked for identification with a single lot designation.

At the time of sampling, all the samples drawn must bear identification corresponding to that of the lot certificate.

The sampler should seal or supervise the sealing of the sample container / bags after drawing sample.

After taking samples which may be more than required for seed testing purpose, a through mixing of the samples is to be done.

Divide it using a seed divider and then the required amount should be submitted to the seed testing laboratory after putting proper identification mark.

If mechanical divider is not available at the spot, a representative sample should be obtained by putting the entire quantity of seed on a clean floor, mixing properly and halving the sample until the desired quantity is obtained.

For moisture determination, 100g of seeds for species which need grinding and 50g for all other species. Sample should be submitted in an air-tight container, like polythene bags of 700 guage or glass bottle with tight cap to the laboratory.

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Quantity and despatch of sample for testing

Weight of submitted sample

                The minimum weight for submitted samples for various tests are as follows.

1. Moisture test

                100 g for those species that have to be ground and 50 g for all other species.

2. For verification of species and cultivar

Despatch of submitted sample

Types of sample used in Seed Testing Laboratory (STL)

Service sample: Sample received from other than seed certification agencies and seed inspectors
Certified sample: Sample received from certification agencies or officers
Official sample: Sample received from the seed inspectors.

For other tests like purity and count of other species

Crop	Size of seed lot (Kg)	Size of submitted sample (g)	Size of working Sample for purity analysis(g)	Sample count of other species(g)
Paddy	20,000	400	40	400
Wheat	20,000	1000	120	1000
Maize	40,000	1000	900	1000
Sorghum	10,000	900	90	900
Bajra	10,000	150	15	150
Redgram	20,000	1000	300	1000
Greengram	20,000	1000	120	1000
Blackgram	20,000	1000	150	1000
Bengalgram	20,000	1000	1000	1000
Cowpea	20,000	1000	400	1000
Soybean	20,000	1000	500	1000
Groundnut(pods)	20,000	1000	1000	1000
Groundnut(Kernels)	20,000	1000	600	1000
Gingelly	10,000	70	7	70
Sunflower(variety)	20,000	1000	250	1000
Sunflower(Hybrid)	20,000	1000	125	250
Cotton linted(variety)	20,000	1000	350	1000
Cotton delinted(variety)	20,000	350	35	350
Cotton linted(hybrid)	20,000	350	35	350
Cotton delinted (hybrid)	20,000	250	25	250
Brinjal	10,000	150	15	150
Chillies	10,000	150	15	150
Bhendi	10,000	150	15	150
Tomato(variety)	10,000	70	7	70
Tomato(hybrid)	10,000	7	7	7
Cabbage	10,000	100	10	100
Cauliflower	10,000	100	10	100
Knolkhol	10,000	100	10	100