Sampling Basics

Sampling Basics - AgEtal
Selecting a representative sample is vital to accurate results. We help you by giving you advice for selecting a seed and grain sample and the quantity needed.
*Some certificates require samples to be taken by an accredited sampler. Find out how to become an ISTA accredited sampler.

Taking a Representative Sample

In seed and grain laboratory testing, small samples are analysed as representing the entire lot from which they were taken; "Representative" being the key word. Most seed and grain sheds have staff who are properly trained to take representative samples. However, if you don’t have staff trained in taking samples, we offer an accredited training course. 

It is worth highlighting some of the important aspects of selecting a sample. Seed and grain lots are dynamically variable – they vary over space and time. Samples drawn from the bottom of a stack or the hot side of a silo may be quite different from samples drawn from elsewhere. Likewise, a sample that is left in a hot car may bear little resemblance to the product in the silo from which it was drawn. Equally, a test result on a sample from a year ago will not be the same as a fresh result. 

To learn more about selecting a representative sample, you and your team can take our Accredited Sampler course - please contact us to make a booking.

The ISTA Sampling Calculator is a great tool to help verify sample size, lot size and more.

How to take a representative sample

To ensure a representative sample:

  1. Take lots of sub-samples randomly from all parts of the seed or grain lot and combine them to make up the sample that you send to the laboratory.
  2. Be sure to give the the sample an identification that will link it to the seed lot that you need tested.
  3. Complete the Request for Analysis form.
  4. Package the sample carefully with the Request for Analysis form and deliver or post it to the AgEtal Laboratory.

Sample Quantity Requirements

Sample Quantity Requirements

When drawing a sample: Refer to the Sample Quantities table below to see how much is required for testing. If the kind of seed is not listed, either send a minimum of 1 Kg or contact the laboratory.

Another great tool is the ISTA Sampling Calculator, found here.

Purity and Weed Seed Searches

The standard quantity required for most seed tests, including Weed Seed Searches apart from Tasmania, is the minimum quantity for a purity test. Please note that these are examples. The laboratory can be contacted for further information.

Western Australian Weed Seed Searches must be sampled by an accredited sampler.

  • Maize - 1000g
  • Chickpeas - 1000g
  • Soybeans - 1000g
  • Sorghum - 1000g
  • Sunflower - 1000g
  • Mungbeans - 1000g
  • Wheat - 1000g
  • Barley - 1000g
  • Oats - 1000g
  • White French Millet - 150g
  • Japanese Millet - 80g
  • Panicum - 90g
  • Signal Grass - 100g
  • Canola - 100g
  • Lucerne - 50g
  • Ryegrass - 60g
  • Buffel - 60g
  • Rhodes Grass - 10g
  • Panic - 20g
  • Carrot - 30g
  • Pumpkin - 1000g
  • Onion - 80g

Germination, Vigour and Tetrazolium tests

Germination, Vigour and Tetrazolium tests on their own require one tenth of the minimum purity weight.

  • Tasmanian Weed Seed Search - 2 Kg (all species)
  • GTA tests - 1 Kg
  • Mungbean Appearance, Oversoak and Charcoal Rot - 200g
  • Popcorn Expansion 500g

Would you prefer to Print or Download this form?

If you would prefer not to complete this form online, you can download or print the form.

Simply complete the form on paper, attach to your sample and post or deliver to AgEtal.

If you require testing to full ISTA methods (i.e. 4 reps instead of 2) or for OIC/BIC please use the ISTA form.

Download ISTA Form

Request for Analysis FormNew Customer Form

Accurate results
in a timely manner.


Request for Analysis.

Simply book online for all your seed and grain testing then drop off or post the sample to our lab.

Please be sure about the tests you require before submitting your Request for Analysis. *See our Cancellation Policy
Test results have a fast turnaround and are available online.

Request for your samples to be analysed in three easy steps.

Complete the
form below.
Sign & attach the receipt
to your sample.
Post or deliver the
sample to AgEtal.

Attach the form to your sample. Post or deliver the sample to AgEtal. For fast turnaround, please deliver samples before 3:30pm.

Thank you for requesting an analysis

We have received your request for analysis, don't forget to print and sign the receipt below to attach to your samples. Send or deliver your samples to our laboratory. If you have any questions, please contact us.

We will be in contact with you when your results are ready.

Print Receipt

Attach the form to your sample. Post or deliver the sample to AgEtal.

AgEtal Request Analysis

Customer Details
Accounts Payable Details
Analysis Details 1
Lab. No. (Office use only)
Analysis Details 2
Lab. No. (Office use only)
Analysis Details 3
Lab. No. (Office use only)
Analysis Details 4
Lab. No. (Office use only)
Analysis Details 5
Lab. No. (Office use only)
Analysis Details 6
Lab. No. (Office use only)
Analysis Details 7
Lab. No. (Office use only)
Analysis Details 8
Lab. No. (Office use only)
Accredited Sampler & Other

* Abbreviations: Purity = P  Germination = G  Vigour = V  Tetrazolium = Tz  |  Weed Search = WS

A booking receipt will generate when submiting this form. (a confirmation will sent to the nominated Customer email)

Test results have a fast turnaround and are available online.

Please remember to complete the final steps when you submit this form.

Sign & attach the receipt
to your sample.

(Booking Receipt)
 Post or deliver the
sample to AgEtal.

Export Information (if applicable)
Analysis Submit
Issued by Luanne Cunliffe Director Webform WAM03 01/09/21

Contact AgEtal Agricultural Testing Laboratory

Get in contact with our laboratory to book an analysis or learn more about our testing.

Phone 07 4633 3223

Courier 9/24 Carroll St Toowoomba QLD 4350

Auspost PO Box 7135 Toowoomba South 4350

Opening Hours

Monday to Friday
8:30am to 5:00pm

Saturday & Sunday
Closed to the public

Counting is done every day – after hours drop off box available.

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