![]() ![]() tomato) can be a serious disease of tomatoes and can be difficult to control when disease pressure is high and favorable environmental conditions are present. Management: clean planting material, seed treatment, sanitation, weed control, crop rotationīacterial speck (bacterium: Pseudomonas syringae pv. Bird’s eye spots (tan to brown spots surrounded by creamy-white halos) may develop on fruits ( Figure 1). Leaflet margins may turn brown and be bordered by yellow margins ( Figure 1). Adventitious roots may also develop on stems. Light yellow to brown streaks that eventually turn reddish-brown develop in vascular tissues and are more clearly visible at plant nodes. Stems may develop dark streaks that may split to expose a brown canker (defined, dry, necrotic lesion). Wilting typically begins in the lower portion of the plant and then moves up however, wilting can begin at the point of pathogen entry when plants are wounded. Symptoms: A variety of symptoms may be produced in tomatoes infected with the bacterial canker pathogen. The pathogen can also be spread from plant to plant on workers’ hands and by splashing water and pruning. The pathogen is seedborne and can survive in infected plant debris and weed hosts and on surfaces and production supplies (stakes, trays). ![]() michiganensis) can be a significant disease in tomatoes grown in the greenhouse. Management: crop rotation, cultural practices, sanitation, fungicidesīacterial canker (bacterium: Clavibacter michiganensis subsp. When moist conditions are present, salmon-colored spores, visible in masses, may be produced on the surfaces of lesions. Eventually, small, black spots (microsclerotia) develop in the tan centers of lesions. These lesions may enlarge, become more sunken, and merge together. Signs/symptoms: Small, slightly depressed, circular lesions (localized areas of diseased tissue) develop on ripe fruit. Splashing water from rain or overhead irrigation can spread the pathogens. The pathogens can survive from crop to crop on plant debris and in the soil and have a broad host range. Moist conditions promote disease development. Fruit that is not yet ripe may also become infected however, symptoms will only appear when the fruit begins to ripen. Diseases of TomatoesĪnthracnose (fungi: Colletotrichum spp.) is primarily a problem on fruit that is ripe (or overripe), although leaves, stems, and roots may become infected. Common disorders in tomatoes are, however, described in MSU Extension Publication 2975 Tomato Troubles: Common Problems of Tomatoes. To learn about common diseases of tomatoes that more commonly occur in greenhouses and how to manage them, see MSU Extension Publication 1861 Greenhouse Tomatoes: Pest Management in Mississippi.Īdditionally, while some disorders are often mistaken to be diseases or are sometimes referred to as abiotic (nonliving) diseases, disorders are also not described in this publication. While the information in this publication may be relevant to tomato production and disease management in any location, this publication does not focus on methods that pertain to managing diseases of tomatoes in the greenhouse. Additionally, some disease management methods for tomatoes grown in greenhouses are unique to those structures since the environment in these structures can be manipulated. Notes: Many diseases of tomatoes occur both in the field and in enclosed structures however, because of the unique nature and environmental conditions present in enclosed structures, some diseases are more common in these structures, whereas others are more common in the field. General disease management methods that can be used to prevent or reduce disease are also described following the descriptions of the common diseases. These terms are formatted in bold italics at their first mention within the text and are defined in the Glossary of Plant Pathology Terms at the end of this publication. Several plant pathology-related terms are used in these descriptions. This publication provides information on many of the most common diseases of tomatoes that occur in Mississippi, as well as descriptions of the signs (the visible presence of a pathogen) and symptoms (a plant’s reaction to infection with a pathogen) associated with those diseases. Identifying the cause of a problem is necessary before appropriate management methods can be taken. A few fungus-like organisms ( oomycetes) commonly called water molds also cause troublesome diseases in Mississippi.ĭiagnosis is the first step in disease management. Many of the most common diseases that affect tomatoes in Mississippi are caused by various fungi, bacteria, and viruses. A number of disease-causing organisms ( pathogens) can infect tomatoes and cause disease. ![]()
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