Bacterial wilt of pepper

Clavibacter capsici is a destructive phytopathogenic bacterium that primarily affects Solanaceous crops, with a specific and devastating impact on peppers. As a vascular pathogen, it creates severe economic losses by inhibiting the plant's ability to maintain water homeostasis and structural integrity.

The primary host for this pathogen is the pepper plant, including both bell and chili varieties. Once the bacteria enter the vascular system, they multiply rapidly within the xylem vessels, producing extracellular polysaccharides that physically obstruct the movement of water and nutrients, eventually leading to plant collapse.

Symptoms initially manifest as slight flagging or wilting of the leaves during the hottest part of the day, with recovery occurring at night. As the infection progresses, the wilting becomes permanent, the foliage turns chlorotic or necrotic, and the plant dies. A definitive sign of Clavibacter capsici is the internal browning of the vascular tissue visible upon cutting the stem.

The development and spread of this disease are heavily favored by high temperature and high humidity conditions. The pathogen is easily disseminated through contaminated irrigation water, infested soil, infected seeds, and agricultural tools that have not been properly sanitized between uses, making farm hygiene critical for disease suppression.

Effective management requires an integrated approach to break the infection cycle. This includes using certified disease-free seeds, implementing a long-term crop rotation strategy to reduce soil inoculum levels, and ensuring proper drainage to prevent water stagnation. Once infected plants are identified in a field, they must be immediately rogued and destroyed to minimize further bacterial spread.