Sugar Beet (Beta vulgaris) -- Bacterial Vascular Necrosis and Rot (Erwinia Root Rot)
 
Hosts: Sugar beet
Cause: This disease is caused by a bacterium, Erwinia carotovora subsp. betavasculorum, present in many native and cultivated soils. This pathogen can survive in some weedy hosts. Portions of the bacterium that causes potato blackleg can be pathogenic to sugar beets. The disease is favored by plant wounding, excessive nitrogen or moisture, and warm temperatures (optimum is 79 to 82° F). The disease occasionally is severe in Idaho.
Symptoms: Black streaks may be found on petioles, and crowns may be blackened or produce froth. Vascular bundles are brown, and adjacent tissue turns pink when cut and exposed to air. Rot can become extensive soft or dry rot.
Cultural control: Most sugar beet varieties have resistance, but losses still can occur.
  1. Maintain a 6- to 8-inch plant spacing, which helps to keep soil cooler.
  2. Minimize plant injury.
  3. Avoid excessive nitrogen.
  4. Avoid excessive irrigation.
  5. When hilling, avoid pushing soil into the crowns.

http://ipmnet.org/plant-disease/disease.cfm?RecordID=1217

   

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