Germinative measurements test a barleys germination energy, capacity (viability), and water sensitivity. 

 

Germination Energy (GE):

100 seeds are placed in a petri dish with 4mL of water - germinated seeds are counted and removed over a three day period

During the test the petri dishes are kept at constant temperature (20C) and  high humidity

Ideally 95% or more of the seeds germinate

If less than 95% germinate the grain may be dormant and just needs more time/cold treatment, or it may be dead

 

Germination Capacity (GC):

Used to determine if seeds that did not germinate in the GE test are dormant or dead

A dilute hydrogen peroxide mix is added to the 4 mL petri dish containing un-germinated seeds (after 3 day GE test is completed and the seeds that did germinate have been removed)

The seeds are checked after two days - those that have germinated were dormant, those that have not are dead

 

Water Sensitivity (WS):

Alongside the GE test a second set of 100 seeds are placed into a petri dish with 8mL of water - germination is counted over three days

The total germination is compared between the 4mL and 8mL tests. If the 8mL seeds have reduced germination of 30% or more the seed is considered water sensitive.

 

Example Germination Record

Sample

Germinative

Energy

Germinative

Capacity 

Water

Sensitivity

 

Result

 

Decision

Variety 1

  96%

 100%

 2%
 No dormancy or water sensitivity
Ready to malt
 
 
 
 
 
 

Variety 2

 79%
 99%
 3%
Variety shows dormancy as the 4mL energy is not >95% but the grain has the capacity as seen with GC at 99%
Wait a few weeks and test again
 
 
 
 
 
 

Variety 3

 82%
 84%
 5%
High percentage of dead kernels evident due to Germinative Capacity (<95%)
Do not malt
 
 
 
 
 
 

Variety 4

 97%
99%
 36%
Difference between the 4mL and 8mL germination is greater than 30%, meaning that there is water sensitivity
Adjust steeping regime accordingly