more... > Disease Image Gallery > Herbs & Vegetables > Tomatoes > Tomato Southern Blight [Image: Image courtesy of Clemson University - USDA Cooperative Extension.] Southern blight (or southern wilt) is a disease of hundreds of plant species, including tomatoes. It is favored by moist conditions and high temperatures. The fungus can survive for years in soil and plant debris. Tomato Fusarium Wilt [Image: Click here to view larger image.] Fusarium wilt is a warm-weather disease, and infection occurs through wounds in the roots. Disease symptoms include seedling stunting, drooping and downward curling of older leaves and discoloration of the vascular tissue. This is usually noticeable during the period from blossoming to fruit maturation. This pathogen is soilborne and can remain in infested soils for several years. Tomato Bacterial Speck [Image: Click here to view larger image.] Bacterial speck is favored by cool temperatures and high-moisture conditions. Severe fruit spotting can decrease yield potential by reducing its marketability. Tomato Bacterial Spot [Image: Click here to view larger image.] Bacterial spot is present wherever tomatoes or peppers are grown. Crop losses result from both defoliation and spotting on the fruit, reducing yield potential and fruit marketability.  more articles... Tomato Bacterial Wilt [Image: Click here to view larger image.] Bacterial wilt is a soil-borne disease found in warm, temperate, subtropical and tropical areas. Ralstonia solanacearum (previously called Pseudomonas solanacearum) enters its host through roots and colonizes the xylem elements in the vascular tissue. Ralstonia has an extremely wide host range with well over 200 hosts reported. Tomato Diseases [Image: Photo of red & green tomatoes] Plant diseases can become the limiting factor ito tomato production worldwide. There are nearly 200 known tomato diseases of diverse causes and etiologies. Control of these diseases involves host resistance, exclusion, eradication and most importantly, use of best management practices. Early Blight of Tomato [Image: Click here to view larger image.] Early blight is one of the most common tomato diseases and is distributed world-wide. Early blight is generally found in humid or semiarid climates where frequent dews provide significant moisture for disease development. This disease can result in severe crop losses due to defoliation and reduction in fruit size and quality.