By Clint Thompson
The Georgia Cotton Commission reminds producers that with the excessive rainfall this summer comes increased risk for diseases. Bob Kemerait, University of Georgia Extension plant pathologist, encourages growers to scout their fields for diseases like target spot.
“The most important message I can send to growers right now is to recognize, in addition to the benefit (rain) brings, rain on a cotton crop does creates situations where they need to be more observant, more aware of the potential for target spot and other situations and how they can correct that,” Kemerait said.
“The most important way to protect against a disease like target spot is to put boots in the field to see, ‘Do we have it?’ ‘Do we have it developing?’ If it is, what can we do to take care of it, whether it’s through ground-driven spray booms, whether it’s through chemigation or some other method, some way to get fungicides out on the crop.”
Target spot begins as a small spot and develops into white lesions with target-like concentric circles on them. Growers should also be wary of other diseases like areolate mildew and Stemphylium leaf spot, which is caused by a potassium deficiency.
“Really, we’ve got a perfect storm for diseases like target spot and eventually areolate mildew. We also have another disease called Stemphylium leaf spot. Sometimes with the rains we’ve had, we’re going to be leeching potassium out of the soil. When you leech potassium, what happens is that potassium deficiency manifests itself as a disease called Stemphylium leaf spot,” Kemerait said.