A wetter than usual July produced an ideal environment for making a good cotton crop in southwest Oklahoma this year, but it also created near perfect conditions for bacterial blight, a foliar disease that may not be an annual occurrence, but can be devastating when it appears.
The blight occurred in a year with limited pressure from the usual suspects, says Randy Boman, research director at the Oklahoma State University Southwest Research and Extension Center at Altus, and state Extension cotton program leader.
“We typically don’t have root knot nematode or Fusarium wilt problems,” Boman says, “and we had very little Verticillium wilt.”
Boman says bacterial blight is not new; it shows up occasionally, and is one of those pathogens that may be around all the time, just looking for the right environment to show itself. It’s not something growers face every year, “and it’s not often a big deal — unless it happens to you.”
More than a few southwest Oklahoma cotton farmers report varying degrees of damage from the pathogen this year. Loss ranged from just a few pounds to more than a bale per acre. Boman says producer should know what symptoms to look for and offers the images here as a guide.
He’ll tell producers in winter meetings to look for resistant cotton varieties for 2017 planting. Producer who planted resistant varieties this year reported no bacterial blight damage, he says.
Photos courtesy of Randy Boman, OSU