⚠ CriticalRalstonia solanacearum colonises xylem vessels in the vascular system, physically blocking water transport — the plant wilts as if severely drought-stressed despite adequate soil moisture, as water cannot reach the canopy through the occluded xylem.
Bacterial Wilt — Ralstonia & Erwinia Vascular Infection
Commonly affects: Anthurium andraeanum, Philodendron spp., Alocasia spp.
The plant wilts suddenly and completely despite adequate soil moisture and no root rot symptoms. Wilting may affect individual branches or the entire plant simultaneously. If a wilted stem is cut transversely, the vascular tissue (xylem bundles) appears brown or discoloured rather than white. In Ralstonia infections, a milky bacterial ooze may exude from cut stems when squeezed. The plant does not recover after watering — vascular damage is irreversible once systemic infection is established.
Potential Causes
- 1Ralstonia solanacearum or Erwinia (now Pectobacterium) infection entering through root wounds, insect feeding damage, or contaminated cutting tools
- 2Introduction via infected soil, water, or plant material from a contaminated source
- 3Soil-to-plant transmission through infected irrigation water or splashback from contaminated substrate
- 4Insect vectors (thrips, aphids) transmitting the bacteria between plants during feeding
Solution Steps
- 1Confirm diagnosis by cutting a stem transversely and squeezing — if bacterial ooze is present and the xylem is discoloured, bacterial wilt is likely rather than a fungal issue.
- 2There is no curative treatment for established systemic bacterial wilt — infected plants should be removed and destroyed (do not compost).
- 3Isolate all adjacent plants immediately. Decontaminate all tools, pots, and surfaces with 10% bleach solution or 70% isopropyl alcohol.
- 4If only one branch is affected and the main stem is symptom-free, aggressive pruning back to visibly healthy tissue plus copper bactericide treatment may save the plant — but full recovery is rare once the main vascular system is colonised.
- 5Drench surrounding soil and containers with a copper bactericide to reduce the bacterial load in the growing environment.
- 6Do not reuse pots or substrate from infected plants — destroy or fully sterilise before use with any new plant material.
Prevention Tip
Sterilise all cutting tools between plants with a 10% bleach solution or 70% isopropyl alcohol. Ralstonia and Erwinia enter primarily through wounds — clean tools are the most effective prevention against systemic bacterial diseases in plant collections.
Related Issues to Explore
Erwinia Soft Rot — Pectobacterium Infection in Aroids
Erwinia (Pectobacterium) causes soft rot in the same genus of plants susceptible to bacterial wilt — distinguish by the tissue type affected (soft, mushy crown vs. firm vascular browning).
Read guideXanthomonas Bacterial Blight — Vascular Systemic Infection
Xanthomonas similarly causes vascular discolouration and wilt — copper bactericides and tool sterilisation are the shared prevention and management strategy.
Read guide
