{"id":499,"date":"2026-09-21T21:52:40","date_gmt":"2026-09-21T20:52:40","guid":{"rendered":"https:\/\/www.coltivobio.com\/en\/?p=499"},"modified":"2026-09-21T21:52:40","modified_gmt":"2026-09-21T20:52:40","slug":"tomato-anthracnose","status":"publish","type":"post","link":"https:\/\/www.coltivobio.com\/en\/tomato-anthracnose\/","title":{"rendered":"Tomato Anthracnose: Symptoms, Prevention, and Control"},"content":{"rendered":"

Tomato anthracnose is a fungal disease caused by several species belonging to the genus Colletotrichum<\/em>. It primarily affects ripe tomatoes and can cause significant losses during harvest, storage, and marketing. The disease is especially common under warm temperatures, repeated rainfall, and high humidity.<\/strong><\/p>\n

Symptoms of Tomato Anthracnose<\/strong><\/h2>\n

The most characteristic symptoms appear on ripe or overripe tomatoes. Initially, small, circular, water-soaked, and slightly sunken spots develop on the fruit (see photo below). As the infection progresses, the lesions enlarge, become darker, and gradually sink deeper into the flesh.<\/p>\n

\"Early
Early symptoms of tomato anthracnose, with the formation of sunken, water-soaked lesions.<\/figcaption><\/figure>\n

The center of the spots may become tan, dark brown, or nearly black and develop small fungal fruiting structures, known as acervuli, sometimes arranged in concentric rings (see photo below). Under highly humid conditions, cream-colored, pink, or salmon-colored spore masses may appear. Individual lesions can merge, resulting in the rapid decay of the entire tomato.<\/p>\n

\"Mature
Mature lesions with dark brown to black concentric rings inside the sunken areas.<\/figcaption><\/figure>\n

Green tomatoes may become infected without showing visible symptoms. The fungus remains latent and resumes development as the fruit ripens. For this reason, tomatoes that appear healthy at harvest may develop rot later during storage or marketing. Tomato anthracnose is therefore considered primarily a disease of ripe and overripe fruit.<\/p>\n

\"Early
Early symptoms: sunken lesions followed by the gradual development of necrotic tissue, which becomes more evident at later stages.<\/figcaption><\/figure>\n

What Causes Anthracnose on Tomatoes?<\/strong><\/h2>\n

The disease can be caused by several species of Colletotrichum<\/em>. Species associated with tomato include Colletotrichum coccodes<\/em>, C. dematium<\/em>, and other species belonging to different taxonomic complexes.<\/p>\n

Colletotrichum coccodes<\/em> can also infect tomato roots, stems, and leaves. On roots, it can produce small black microsclerotia and contribute to the development of a root disease known as black dot root rot<\/strong>. Accurate identification of the species normally requires laboratory analysis because the symptoms produced on tomato fruit can appear very similar.<\/p>\n

\"Advanced
Advanced symptoms on a ripe tomato, with extensive areas of fruit rot.<\/figcaption><\/figure>\n

Disease Cycle and Spread<\/strong><\/h2>\n

The fungus can survive in infected crop debris, tomatoes left on the ground, volunteer plants and weeds belonging to the nightshade family, and, in the case of certain species, in the soil and on infected roots.<\/p>\n

When environmental conditions become favorable, the pathogen produces conidia. These spores are carried onto tomato plants by splashing rain and overhead irrigation. Tools, hands, and crop operations performed while the plants are wet can also contribute to disease spread.<\/p>\n

Free water on the fruit surface promotes spore germination and infection. Conditions that favor tomato anthracnose include:<\/p>\n