Pseudomonas floridensis bacterial disease

Pseudomonas floridensis is a gram-negative plant pathogenic bacterium responsible for various bacterial spots and blights on susceptible crops. It functions as a systemic pathogen, invading the vascular tissues and parenchymal cells of the plant host, which triggers local hypersensitive responses or progressive necrosis depending on the host plant's resistance.

This pathogen primarily targets vegetable crops, such as tomatoes, peppers, and occasionally ornamental foliage plants. It acts as an opportunistic pathogen that can severely impact the quality and marketable yield of the harvest, especially when infection occurs during the fruit-set or vegetative development stages.

Clinical signs of infection typically manifest as angular water-soaked lesions on the foliage. As the disease progresses, these lesions develop a yellowish halo, eventually turning brown or necrotic. Under high humidity, a bacterial exudate might be visible on the underside of the leaves, which acts as a primary source of inoculum for secondary infection spread throughout the field or greenhouse.

The spread of Pseudomonas floridensis is highly dependent on environmental parameters. Warm temperatures combined with high moisture levels (rainfall, overhead irrigation, or condensation) are the most favorable conditions for bacterial multiplication. The pathogen enters the host plant through wounds caused by tools, insects, or environmental stress, such as hail or wind damage.

Effective management strategies rely on a multi-modal approach to suppress bacterial populations. This includes strict sanitation protocols, such as disinfecting greenhouses and equipment, and the use of copper-based bactericides for early prophylactic treatment. Crop rotation and the selection of certified, disease-free planting material remain the most sustainable methods to reduce the risk of outbreaks in both commercial and greenhouse environments.