Introduction: The Bacterial Adversary in Potato Production
Potato brown rot, also known as bacterial wilt, is one of the most destructive diseases of potato worldwide, caused by the Ralstonia solanacearum species complex (RSSC), a Gram-negative, soil-borne bacterium. The pathogen causes severe yield and quality losses in potatoes (Solanum tuberosum) and other solanaceous crops such as tomato, pepper and eggplant. Infection results in rapid vascular wilting, plant collapse and tuber decay. Globally, the disease leads to billions of dollars in annual economic losses, particularly in tropical and subtropical regions; however, certain strains, notably race 3 biovar 2 (R3bv2) are also capable of infecting crops in cooler temperate climates.
RSSC typically invades plants through natural openings or root wounds often exacerbated by nematode damage and colonizes the xylem vessels. The bacterium secretes exopolysaccharides (EPS) and type III effector proteins that block water transport, causing wilting and eventual death of the plant. It thrives under warm, humid conditions (25–35 °C for most strains, 12–24 °C for R3bv2). Poor soil health, contaminated irrigation water and global seed or tuber movement accelerate its spread.
Effective management relies on integrated pest management (IPM) strategies combining resistant varieties, strict sanitation, crop rotation and use of pathogen-free planting material. As climate change alters temperature and rainfall patterns, the potential distribution of R. solanacearum is expanding, posing an increasing threat to global potato production and food security.

Tuber Infection Symptoms of Potato Brown Rot: Vascular Browning and Bacterial Exudate




