Cotton Diseases a Factor for Georgia Producers

Clint Thompson Cotton, Georgia, Georgia Cotton Commission

UGA Extension photo/Shows bacterial boll rot disease.

By Clint Thompson

The Georgia Cotton Commission and University of Georgia Extension plant pathologist Bob Kemerait caution growers about various diseases that could be problematic over the final weeks of this year’s production season.

Kemerait said the excessive rains this summer have sparked three diseases that growers need to be wary of.

“With all the moisture we’ve had and with all the rain, in a lot of ways it’s been a fantastic cotton crop. In my world, rain brings diseases. We’ve got three diseases I want to talk about; one is target spot, one is areolate mildew. A lot of our growers are now familiar with target spot. The areolate mildew they’re not familiar with. It looks like powdery mildew on the back of the leaf,” Kemerait said. “Both of them can rapidly defoliate the crop. If you’re at sixth week of bloom or beyond, you probably don’t need to worry about target spot. We worry about areolate mildew as far as protecting the crop to within a month you’re planning to defoliate. If you’re within a month of defoliating, don’t worry about it.

“The good news about target spot and areolate mildew, judicious use of a good fungicide program and you can really protect your yield.”

However, the same can’t be sad for boll rot. It is a disease that Kemerait expects to see a lot of, leading up to harvest.

“The humidity, rain, rain splash; my biggest concern for cotton growers in Georgia this year is going to be boll rot. Unfortunately, there’s not much we can do about it,” Kemerait added. “It could be really tough this year.”

He said that it is not just the weather that is a factor. Because the cotton plants have very good leaf canopy, they are able to trap the moisture.

“Every cotton grower is going to have some level of boll rot. The question is going to be what’s the overall loss going to be?” Kemerait added.