Edisto cotton field day studies “hardlock”

By Tom Lollis

Cotton BallCotton growers learned about the role that fungicides may play in controlling “hardlock” at the fall field day Clemson’s Edisto Research and Education Center’s fall field day in Blackville.

Hardlock is when lint in the cotton boll fails to fluff enough to be picked up by the spindles of a picker. The affected bolls fall apart and drop to the ground when the spindles hit them. Yields can be cut by 15-20 percent in a wet year like this one, said John Mueller, a Clemson plant pathologist at the Edisto center.
He is part of an interstate team of scientists who are looking for solutions to this problem. One theory is that a fungus, Fusarium verticillioides, causes the condition. Damage from stinkbugs and other insects is another theory. If fungus is the cause, the solution could be as simple as spraying with a fungicide to protect flowers from damage.

To test this theory, Mueller is comparing two cotton varieties with different growth habits to see how they develop and to see if applying fungicides really does have an effect.       
“We want to see if there is a yield response, and to see if it is consistent enough to apply for labels for these fungicides,” says Mueller. Currently no fungicides are labeled for use on cotton but that may change if these test results are positive.

Growers also saw demonstrations of cotton variety trials, variable-rate irrigation systems, and control strategies for insect pests.