As many growers begin sowing in 2026, utilisation of retained seed from harvest last year is likely to be a key part of planning this season. Difficult conditions in 2025, including a dry growing season and several frost events, could potentially have an impact on seed quality and therefore future crop performance. Seed quality testing is a vital tool that can help avoid financial losses from failed crop establishment and set your paddock up for success.  

What are the reasons for testing your seed? 

• Seed is a low-cost input, but it is the most valuable operational input 

• Weather-damaged seed is more susceptible to poor germination, low vigour and degradation during storage 

• Poor or delayed germination can result in crop growth outside the optimal window.  

• Can prevent significant weed and disease issues through detection of contamination such as weed seeds or pathogens.  

• Allows growers to determine the required sowing rate for the desired plant density.  

There are multiple seed quality tests that can be conducted to provide information about retained seed; 

Germination Test

A germination test determines the viability of the seed and will report the maximum germination percentage as well as normal, abnormal, fresh, hard and dead seeds. Normal seeds show potential to develop into adequate plants when sown in favourable conditions, while abnormal seeds may develop but can be deformed or damaged. Fresh and hard seeds behave differently in a germination test in terms of water uptake and may or may not develop into plants, while dead seeds won’t develop at all. A high germination percentage indicates seed is likely to germinate under ideal sowing conditions, and the opposite for a low germination percentage. For example, a 95% germination rate indicates 95 out of 100 seeds should germinate under ideal conditions.  

Thousand Seed Weight Test

A thousand seed weight (TSW) test is a measure of seed size, and can vary depending on the conditions and the age of the seed. Seed size influences plant density, as large seeds require a higher sowing rate than smaller seeds to achieve the same target plant density. Both germination percentage and thousand seed weight can be used in the following formula to calculate a suitable sowing rate based on the quality of your seed.  

 Sowing rate (kg/ha) = 1000 seed weight (g) x desired plants/m2 ÷ germination percentage 

 Frost that occurs during grain fill, as was the case in parts of south-west Victoria in 2025, can cause a 20-50% reduction in crop establishment due to damaged retained seed. Consequently, growers may need to increase sowing rates the following year to compensate for lower crop germination and poor vigour of frosted grain.  

To receive the best possible information about your seed, it is advised to submit your seed samples to a reputable laboratory that can complete these quality tests. Seed quality testing is a crucial step in reducing the risk of crop failure, and ensuring you are setting your paddock up for success this season.  

By Cam Barr, Research & Extension Officer