seed coat

Weather Main Factor in Seed Coat Fragment Issue

Clint Thompson Cotton, Georgia

seed coat
A typical cotton sample with seed coat fragments identified in blue circles.
Credit: AMS Cotton & Tobacco Program.

One of the main takeaways from the 2020 cotton season remains the issue with seed coat fragments and the abnormally high number of reported instances in cotton this year.

Ed Barnes, Senior Director, Agricultural & Environmental Research at Cotton Incorporated, talked to Georgia cotton producers during Wednesday’s annual Georgia Cotton Commission meeting about the surge in seed coat fragment occurrences. He is confident the poor weather at harvest was the overwhelming factor.

“This was definitely a historic anomaly, and we’re very confident that this was a weather event,” Barnes said. “Everything we’re seeing indicates that this was due to a crazy weather event.”

Increase in Hurricanes

Last season was also highlighted by an abnormal amount of hurricanes to impact the Southeast, specifically, Hurricane Sally on Sept. 16. It dropped heavy amounts of rainfall that led to the seed coat fragment issue.

“Hurricane Sally, you see from the National Weather Service (some areas) had over 10 inches of rain all the way down to four or five inches. That really set us off to a bad start as we approached harvest,” Barnes said.

“We know that when the bolls get wet, we’ll get seed sprout in the boll. That is going to lead to seed coat fragments. I’m not saying that everybody had seed sprout, but that’s one reason wet cotton contributes to seed coat fragments. When that seed gets wet, it takes longer to dry than the fiber. You can think your cotton is ready to harvest. You harvest it, turns out that seed is still very wet when it comes to the gin.”

Relative Humidity

Cloudy days and smaller rain events in September contributed to the problem as well, especially with regards to relative humidity.

“When relative humidity hits 70% we do not recommend harvesting cotton because the fiber and seed absorb enough moisture that it’s going to be too wet when you go to store it. Right around Sally, not just when Sally hit but before and after, we had many days where the humidity never fell below 70%,” Barnes said. “That really continued for much of September until early October.”

Seed coat fragments are ground-up seed or extremely small seed or underdeveloped seed that gets through the ginning process and falls with the lint and gets in the lint sample. According to a USDA press release in early January, the Agricultural Marketing Service Macon, Georgia Classing Office had classed 2.2 million samples, of which 895,000 contained seed coat fragments.

About the Author

Clint Thompson

Multimedia Journalist for AgNet Media Inc.