{"id":94,"date":"2026-02-05T19:45:20","date_gmt":"2026-02-05T19:45:20","guid":{"rendered":"https:\/\/www.coltivobio.com\/en\/?p=94"},"modified":"2026-02-25T09:08:10","modified_gmt":"2026-02-25T09:08:10","slug":"bacterial-spot-of-tomato-symptoms-and-control","status":"publish","type":"post","link":"https:\/\/www.coltivobio.com\/en\/bacterial-spot-of-tomato-symptoms-and-control\/","title":{"rendered":"Bacterial spot of tomato: symptoms and Control"},"content":{"rendered":"

Bacterial spot of tomato is a bacterial disease caused by Xanthomonas vesicatoria<\/em>. This disease can also affect pepper. Below are the symptoms, damage, and management strategies for this plant pathology.<\/strong><\/p>\n

Symptoms and damage of the bacterial disease<\/strong><\/h2>\n

The bacterium Xanthomonas vesicatoria<\/em> is the causal agent of bacterial spot of tomato, one of the three most dangerous bacterial diseases affecting this crop, together with bacterial canker of tomato<\/strong> and bacterial speck<\/strong>.<\/p>\n

The disease initially appears as small necrotic spots with irregular margins<\/strong>, mainly visible on the underside of the leaves<\/strong>. In some cases, necrosis may expand to involve large portions of the leaf margins.<\/p>\n

Leaf symptoms can be confused with those caused by Pseudomonas syringae<\/em> pv. tomato<\/em>; however, bacterial spot is distinguished by its characteristic fruit symptoms<\/strong>.
On immature fruits, the disease causes sunken necrotic lesions<\/strong> surrounded by a dark green halo<\/strong>. As the fruit ripens, these areas darken and often crack<\/strong>, leading to fruit deformation and allowing the entry of secondary pathogens.<\/p>\n

\"tomato
Damage caused by Xanthomonas vesicatoria on tomato fruits. Photo source: www.plantdiseases.org<\/a><\/figcaption><\/figure>\n

Pepper<\/strong> plants can also be infected, showing similar symptoms. Yield losses can be severe, particularly in processing tomatoes<\/strong>, while fresh-market tomatoes<\/strong> affected by bacterial spot are unmarketable due to visible fruit damage.<\/p>\n

The development of the bacterium is favored by high relative humidity<\/strong> and temperatures between 22 and 26 \u00b0C<\/strong>. Infection occurs through stomata and wounds<\/strong>, making adverse weather events such as hailstorms<\/strong> and strong winds<\/strong> especially risky. In these cases, treatments with copper-based<\/a> products<\/strong> are recommended within 24\u201348 hours<\/strong>.
Humans also play an important role in disease spread, both through agronomic practices that cause plant injuries and through the use of infected seed<\/strong>.<\/p>\n

Control and management of bacterial spot of tomato<\/strong><\/h2>\n

There is no curative treatment for this disease; management is therefore mainly preventive<\/strong>. Preventive strategies include:<\/p>\n