Cotton Seed Quality

April 9, 2023

Q. What is a warm germination test?

A Warm Germination Test (WGT), or standard germination test, helps indicate seed viability by determining the seed’s ability to germinate under ideal growing conditions. The WGT result is required by law to be included on seed labeling and is generally valid for up to 6 months. The results of this test are comparable across seed providers because the testing methods are standardized through regulation and are consistent from company to company.

Q. What is a cool germination test?

A Cool Germination Test (CGT) helps indicate seed vigor by testing the ability of the seed to germinate in less-than-ideal conditions. This test is not required by law and is not comparable across seed companies as testing methods are not standardized. Bayer rigorously follows the suggested testing guidelines outlined in the Association of Official Seed Analysts (AOSA) Vigor Testing Handbook for conducting the Cotton CGT. The WGT and CGT are only two components of our quality management system used to provide the highest quality seed.

Q. What is Bayer’s standard warm and cool germination test percentage for cotton seed? ​

Bayer takes a lot of pride in providing farmers with the best quality product. Our internal standard minimum WGT percentage for cotton seed is 80%, and a minimum score of 60% is used for the CGT. However, in years where the environment impacts seed quality, we may sell cotton seed with lower scores, considering all quality factors that may affect the grower’s experience. Bags tagged below standard go through a review process before being released for sale.

Q. Can a grower obtain warm and cool germination test scores for purchased seed?

Yes. WGT and CGT scores are available to growers by submitting seed lot numbers through their retailer.

Q. Should a grower expect a low stand with a low CGT score?

CGT scores help provide an indication on how fast a seed lot may emerge under poor conditions. For example, a seed lot with an 85% CGT score may withstand poor growing conditions and emerge quicker than a seed lot with a 60% CGT score. Planting both seed lots in optimal conditions may not have any germination difference, and planting into cool and wet conditions with soil temperatures below 65 °F can negatively impact emergence regardless of CGT score It is important to note CGT results are not as reliable as WGT results.1

Q. Does Bayer conduct other seed quality tests prior to selling cotton seed?

Yes. Each lot of cotton seed is tested for several quality parameters. All incoming bulk seed is tested for moisture, maturity, and free fatty acid level prior to being accepted, and both bulk and finished batches of seed are tested for visual mechanical damage.

Q. What are proper storage conditions for cotton seed?

  • Store cotton seed in a cool, dry environment. Storage in warm and humid environments can decrease germination.
  • Handle seed carefully to prevent damage.

1 Edmisten, K. and Collins, G. 2023. Cotton seed quality and planting decisions. NC State Extension. 2023 Cotton Information. AG-417. https://content.ces.ncsu.edu/cotton-information/cotton-seed-quality-and-planting-decisions/.

2 Boman, R., and Lemon, R. 2005. Soil temperatures for cotton planting. Texas A&M Cooperative Extension. SCS-2005-17. http://cotton.tamu.edu/.