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Ralstonia wilt - Ralstonia solanacearum

Damage

Initially, lower leaves of infected plants yellow and wilt, then die. Yellowing and death of upper leaves follow. Symptoms may initially occur on only one side of the plant. Internally, the water-conducting tissue of the plant browns, and then the entire stem rots from the inside out. Finally, infected plants die. One race of this bacteria can cause a serious disease of potatoes, thus it is closely monitored by various government agencies.

Cultural Controls

Bacteria can be moved in symptomless plants or cuttings, or in contaminated soil and plant debris (the pathogen can remain dormant for many years). There are no known treatments that will curatively save plants infected with Ralstonia wilt. If you believe your plants are suffering from this disease, immediately contact your local Department of Agriculture or County Extension agriculture or horticulture agent to arrange for testing.

Remarks

The potassium salts of phosphorous acid are the only treatment that has been shown to protect plants when applied to the roots. This treatment will not protect from above-ground foliar infections.

Chemical Controls

Phosphorous acid

Signal Word: Caution
Pesticide Class: Systemic

Locations Affected

leaves, roots, stem

Plant Environment

greenhouse, outdoors

Scouting Season:

January - Early , January - Mid , January - Late , February - Early , February - Mid , February - Late , March - Early , March - Mid , March - Late , April - Early , April - Mid , April - Late , May - Early , May - Mid , May - Late , June - Early , June - Mid , June - Late , July - Early , July - Mid , July - Late , August - Early , August - Mid , August - Late , September - Early , September - Mid , September - Late , October - Early , October - Mid , October - Late , November - Early , November - Mid , November - Late , December - Early , December - Mid , December - Late

Plants Affected

• Capsicum - Ornamental pepper
• Cosmos - Cosmos
• Cyclamen - Cyclamen

Photos

Wilting, chlorosis and necrosis due to Ralstonia infection of Pelargonium.

Cut black stem, another symptom of Ralstonia

Symptoms of Ralstonia in Pelargonium