Cotton Bacterial Blight Update: July 18, 2014 (UPDATED 7/28/2014)
Over the past seven to 10 days numerous additional reports of bacterial blight have been made from throughout the state. Several additional varieties, have been observed to contain bacterial blight infected leaves and in one situation, bolls. Presently, seven cotton varieties representing four different seed companies have been reported.
Additional bacterial blight has been observed this year in Louisiana for the first time in many years (see: http://louisianacrops.com/2014/07/18/bacterial-blight-angular-leaf-spot-observed-in-louisiana-cotton-fields/ ). In MS, bacterial blight has been reported from 16 counties throughout the state.
Bacterial blight is predominantly a seedborne disease, except in rare situations where the organism overwinters on cotton residue remaining in the field. Rain, overhead irrigation, wind, as well as equipment used in fields when dew is present can move the bacterium to fields of susceptible cotton. Management practices should not be altered in situations where the disease is observed in susceptible cotton varieties. Keep in mind, that the majority of the cotton varieties planted in MS are susceptible to the bacterium.
For more information regarding scouting practices, appearance of the disease, and the specific response of some cotton varieties please refer to: