By O. Neher and C. M. Ocamb
Cause This disease is caused by a bacterium, Pectobacterium betavasculorum (syn Erwinia carotovora subsp. betavasculorum), present in many native and cultivated soils. This pathogen can survive in some weedy hosts. Plant wounding, excessive nitrogen or moisture, and warm temperatures (optimum is 79°F to 82°F) favor disease development. 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.
- Maintain a 6- to 8-inch plant spacing, which helps to keep soil cooler.
- Minimize plant injury.
- Avoid excessive nitrogen.
- Avoid excessive irrigation.
- When hilling, avoid pushing soil into the crowns.