Bacterial Wilt of Solanaceae
Ralstonia solanacearum
Overview
Bacterial wilt of solanaceous crops (Ralstonia solanacearum) is a warm-climate soil-borne bacterium that clogs tomato, potato, pepper, and eggplant xylem. Plants wilt fast, often without yellowing first. Contaminated soil and water keep the pathogen in beds for years. Bacterial Wilt of Solanaceae enters through wounds and natural openings, then rides water films, insects, and contaminated tools. Wet foliage and hail or pruning injuries often precede outbreaks. Causal agent: Ralstonia solanacearum. In regenerative gardens, prioritize sanitation, airflow, and unbroken soil cover over calendar spraying, and intervene early when symptoms appear.
Symptoms
Rapid wilt of the whole plant or one side; cut stems show brown vascular rings and milky ooze in water. Plants die within days. Cool nights do not reverse the wilt as they sometimes do with temporary drought stress. Compare several plants and note whether symptoms spread after rain, insect feeding, or wet foliage. Photograph undersides of leaves and cut stems when wilt is present to refine the diagnosis. Rule out simple drought, fertilizer burn, and herbicide drift before assuming a pathogen - abiotic injury often mimics disease.
Environmental Conditions
Hot
Prevention
Rotate away from solanums for three or more years. Use resistant varieties and grafted plants. Avoid shared irrigation from infected ponds. Solarize or rest beds after an outbreak. Sanitize tools and boots between plots. Mulch to reduce splash, clear season-end debris, and avoid working plants when wet. Design beds for airflow and diverse plantings that support beneficial insects without creating permanent humid pockets around susceptible crops.
Management
Remove plants and the soil immediately around roots. Solarize beds where summers are hot enough. Biofumigant cover crops (mustard family) and grafting onto resistant rootstocks help in serious regions. No foliar spray cures infected plants. Prefer drip irrigation, morning watering, and open spacing so leaves dry quickly. Disinfect pruners between cuts on woody plants. Use copper, sulfur, or biological products only as labeled protectants when pressure is high - they rarely reverse advanced infections alone. Destroy (do not casually compost) highly infectious debris.