Viability

tall-fescue-germinationGermination A physiological viability test which determines the percentage of live seeds that produce normal seedlings under favorable germination conditions. Both AOSA and ISTA require 400 seeds for germination in most cases. *ISTA Accredited Test

tetrazoliumTetrazolium (TZ) A quick biochemical viability test which determines the number of live seeds based on dehydrogenase activity in seeds. It indicates the percentage of live and dead seeds in any sample regardless of its dormancy level. The test can be performed in 24-48 hours. *ISTA Accredited Test

Fluorescence Test for Ryegrass This test requires germinated seedlings, and determines the fluorescence level of any particular ryegrass sample. It is used to estimate a potential contamination of perennial ryegrass with annual ryegrass. This test is performed on all AOSA ryegrass germinations and is used to differentiate Annual from Perennial ryegrass under AOSA rules. It is performed on ISTA samples by request and is not used in ISTA purity calculations. *ISTA Accredited Test