Bacterial blight of anthurium

Causative agent and type of disease: The disease is caused by the Gram-negative bacterium Acidovorax anthurii. It acts as a systemic pathogen that invades the vascular system of the host plant. This condition is categorized as a vascular bacteriosis, where the bacteria colonize the xylem, blocking water transport and leading to the eventual collapse of the plant structure.

Affected crops: The primary host for this pathogen is the anthurium (Anthurium spp.). It is a highly specialized bacterium that predominantly impacts commercial greenhouse production of cut flowers and ornamental potted plants, posing a significant threat to high-value nursery stock.

Symptoms and signs: The infection begins with the formation of small, water-soaked spots on the foliage, often surrounded by a characteristic yellow halo. As the disease advances, these spots expand and coalesce, leading to severe necrosis. A diagnostic feature is the darkening or vascular browning of the petioles and stems, which inevitably results in sudden wilting, despite the soil being moist.

Conditions for development and severity: Development is favored by high relative humidity (above 80%) and temperatures between 25°C and 30°C. The pathogen spreads via contaminated tools, splashing water during irrigation, and infected nursery material. Its severity is extreme; without rapid intervention, an entire greenhouse production cycle can be devastated in a very short period.

Control and prevention measures:

• Strict adherence to sourcing disease-free plant stock.
• Frequent sterilization of pruning shears and other tools using ethanol or bleach.
• Implementation of drip irrigation to avoid leaf wetting.
• Immediate roguing and destruction of symptomatic plants and their potting media.
• Maintaining optimal air circulation and controlling humidity levels in greenhouse environments.