Elements and Performance Criteria
- Prepare replicates for testing
- Prepare seed and tetrazolium solution
- Pre-moisten seed under prescribed temperature and light conditions to reduce possibility of injury to seeds when puncturing or cutting and to enable penetration of the tetrazolium solution
- Remove sticky mucilage from seeds as necessary
- Expose seed tissue before staining as appropriate for the species being tested
- Keep seeds moist before testing
- Prepare tetrazolium solution using distilled water and add trace amounts of fungicide or antibiotics to solution if necessary for the species being tested
- Stain with tetrazolium solution
- Immerse seeds in tetrazolium solution
- Maintain test at a temperature within the range 20 to 40°C, and maintain low light levels to facilitate staining
- Increase duration of staining if temperatures below 30°C are used or decrease if higher temperatures are used
- Decant the solution at end of staining period, rinse seeds with water and keep damp
- Evaluate test results
- Examine and evaluate each seed as viable or non-viable based on staining patterns applicable to the species being tested
- Count the number of seeds considered viable in each replicate
- Calculate the percentage of viable seed in each replicate and determine average percentage of viable seed across all replicates
- Finalise reporting and clean up