• Worldwide distribution. In tropics and sub-tropics. On more than 200 hosts in more than 30 plant families. Several races. Race 1 infects eggplant, capsicum, chilli, potato, tomato and tobacco, and other families. An important disease.
• High temperature and rain favours disease. Bacteria block the water-conducting tubes causing a wilt.
• Place cut stem in water to see 'streaming'.
• Cultural control: avoid infested land; use 4-year rotation, with maize, soybean, brassicas, rice; plant on ridges/raised beds to improve drainage; remove wilted plants immediately; remove soil from shoes, machinery, and tools; graft tomato onto relatively bacterial wilt-resistant eggplant; use resistant varieties.
• Chemical control: none recommended.

Bacterial wilt, bacterial wilt of potato, bacterial wilt of Solanaceous crops

Ralstonia solanacearum. There are a number of races. Based on host range, Race 1 has a host range of over 50 plant families (200 plant species), including chilli, capsicum, peanut, and Solanum species (but more rarely on potato); race 2 mostly affects banana and Heliconia; Race 3 is the potato strain (see Fact Steet no. 479); Race 4, ginger; and Race 5, mulberry.

An alternative system based on carbohydrate substrates divides strains into five biovars, with e.g., Race 1 corresponding to biovars 1, 3 and 4, and Race 3 to biovar 2, and Race 5 to biovar 5.

Under a revised classification system (2005), and based on DNA sequencing, Ralstonia solanacearum has been divided into four groups, reflecting geography (phylotypes), and further by genetic sequence of an important gene (sequevars).