Bacterial wilt

Bacterial wilt, caused by the bacterium Pseudomonas solanacearum (also known as Ralstonia solanacearum), is one of the most destructive plant diseases globally. It is a vascular pathogen that colonizes the xylem, impeding water transport and causing sudden wilting and death of the host plant.

This pathogen has an exceptionally broad host range, infecting hundreds of plant species including solanaceous crops like potatoes, tomatoes, and tobacco. It is also responsible for the devastating Moko disease in bananas, which represents a major threat to global banana production and food security in tropical regions.

The primary symptom is the wilting of foliage, which often occurs during the hottest part of the day and recovers at night. As the infection progresses, the leaves turn yellow and eventually wilt permanently. Cross-sections of infected stems or tubers reveal a characteristic browning of the vascular tissue, often accompanied by the exudation of a milky-white bacterial ooze.

The development and spread of Pseudomonas solanacearum are heavily influenced by environmental factors. The bacterium thrives in warm, humid conditions and spreads efficiently through contaminated soil, irrigation water, infected planting material, and contaminated tools used in routine field maintenance.

Management of this disease is highly challenging due to the lack of effective chemical treatments for infected crops. Therefore, integrated management strategies focus on prevention: utilizing disease-free certified seeds, practicing long-term crop rotation with non-host plants, and ensuring strict field sanitation to prevent the transfer of contaminated soil between farm plots.