Tetrazolium

When Should I Use This Test?
ICIA offers a 24 hour TZ (Tetrazolium) test which provides an estimate of seed viability in a short amount of time. The TZ test identifies problems associated with damage due to mechanical, insect, freeze, heat, seed coat checking, disease, immaturity and sprouting. Although this test is most commonly conducted on soybeans, sorghum, wheat, barley, corn and oats; it can be performed on any species.

What Technique is Used?  
Seeds are pre-conditioned overnight by soaking in water or on a damp germination towel. 100 seeds are placed in a small container and soaked in a staining solution and then each container is placed in a germinator at 35ºC (95ºF) for the appropriate staining period. Each seed is bisected through the embryo using a razor blade to allow the TZ chemical to stain the embryo.

What Do the Results Mean?  
A TZ test can determine cause and percentage of damage and the TZ score is most often very close to the warm germination test result. Potential germ is reported as a % based on normal seeds found.