One-day Workshop: Tolerances in Seed Testing: Applications and Practices and How to Design and Implement a Referee Study

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18.06.2017 08:00 - 17:00


Denver, Colorado


This one-day Workshop will be divided into two parts:

The first part will cover principles and applications of tolerances in seed testing. A brief discussion of sources of variation and how to reduce them will be discussed, and then followed by an explanation of tables used for each test type (purity, germination, vigor, etc.). For each test type, similarities and differences between AOSA and ISTA tolerance tables will be discussed.
The workshop will include hands-on part. Participants will be required to determine whether test results or replications are within tolerance. They will select the appropriate tolerance tables to use from the AOSA and/or ISTA rules, derive applicable tolerance values, and interpret results.

The second part of the workshop will cover how to establish a referee study. It will include setting objectives, variables, treatments, as well as a brief introduction to principles of experimental designs. In-depth discussion of different referee designs, implementation and data interpretation will be included. Emphasis will be given to methods used in purity and germination referee studies. Validation studies will  be discussed as well. Participants will apply their learned skills by developing example referee studies under different situations and to satisfy specific objectives. 

Participants are encouraged to bring their potential referee studies for real-life examples.

Workshop Organisers:

Dr. Sabry Elias, AOSA Statistics Committee Chair
Dr. Riad Baalbaki, AOSA Germination and Dormancy Committee Co-Chair


Renaissance Denver Stapleton Hotel


Part I- Principles and Applications of Tolerances in Seed Testing (Total 5 hours)

Introduction- Variability in Seed Testing (1 hour)

  1. Important statistical terms.
  2. Seed lot heterogeneity.
  3. Sources of variation in seed testing.
Tolerances (1.5 hours) 
  1. What are tolerances and how is a tolerance table created?
  2. How do you determine whether to use one or two-way tolerance tables?
  3. Review of tolerance tables used for different test types: purity, germination, TZ, vigor, trueness to variety, seed moisture and seed count tests.
  4. Similarities and differences between AOSA and ISTA tolerance tables according to test type.
Practical exercises (2 hours): determining whether two test results or replications within a test are within tolerance using the appropriate AOSA and ISTA tolerance tables:
  1. Purity
  2. Germination and TZ
  3. Vigor
  4. Trueness to variety
  5. Seed moisture content
  6. Seed counts
 Open questions and discussion (0.5 hour) of any other types or issues in the application of tolerance tables  

Part II- Referee Tests: Design, Implementation and Data Analysis (Total 3 hours) 

Setting of a Referee Study (1.5 hours): 
  1. Defining experimental objectives.
  2. Choosing the appropriate experimental design: commonly used designs.
  3. Number and quality of samples/lots, number of replications, and desired number of participants in the referee.
  4. Methods of data analysis.
  5. Interpretation of test results.
  6. Conducting validation studies.
Practical Exercises (1.5 hours): purity and germination referee tests.

CAPACITY: 25 Registrants

Participation Fee:  150 USD

Registration Deadline: 1st June 2017 

If you would like to attend the workshop please fill in the registration form. An invoice will be sent to you, which has to be paid before the participation confirmation will be generated. 
All payments are required prior to the 2nd of June 2017 in USD and payable to ISTA. 

Please note: 

For cancellations made before 2nd of June 2017 registration fees are refundable less a 50 USD administration fee.
For cancellations made after 2nd of June 2017 registration fees are non-refundable.


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STI 154 October 2017
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