Verticillium wilt is caused by the fungus Verticillium alboatrum. Quite often verticillium wilt is confused with fusarium wilt. The fungus attacks a wide range of vegetable crops that are used commercially.  Verticillium wilt is more common in areas of the greenhouse that is not sterilized for instance the growth medium and floor. Symptoms of Verticillium [...]

Most seedlings are particularly susceptible to damping-off. In general the disease is caused by the fungi Pythium but some damage also occurs from infection from Rhizoctonia solani. These fungi are found in soils and is not confined to any region. Pre-emergence of damping-off Pre-emergence of damping-off occurs when the seed is infected with the fungi which [...]

Bacterial wilt known as Ralstonia solanacearum biovar 3, formerly known as Pseudomonas solanacearum (SMITH) and Burkholderia solanacearum). Bacterial Wilt also known as Southern bacterial wilt or sleeping disease. It is a serious soil borne disease that is endemic to the tropical, subtropical and the warm, temperate areas of the world. Bacterial wilt lives in the [...]

Bacterial canker (Clavibacter michiganensis) is one of the most destructive diseases of tomatoes which is caused by Clavibacter michiganensis subsp. michiganensis (smith) formerly known as Corynebacterium michiganensis. This is a very serious disease and can survive in plant debris for long periods. The bacteria can also be carried via the seed, that is why it [...]

Powdery mildew background Powdery mildew (Leveillula taurica) is most prevalent in warm, dry atmosphere. The optimum germinating temperature is approximately 25°C with humidity ranging between 50 – 75%. It is quite common for inexperienced growers to identify powdery mildew as downy mildew. The most important differences are powdery mildew are found in summer and on [...]

Early blight (Alternaria solani) is one of the most common funguses found on tomatoes. The fungus infects mainly the leaves, but stem and fruit infection might also occur. Early blight symptoms Infection starts on the older leaves or at the base of the stem, after which it spreads upwards. Initially lesions can be confused with [...]

Late blight background Late blight (Phytophthora infestans) is very destructive under conditions of excessive moisture and low temperatures. Starts as small water soaked lesions which rapidly enlarge with a brown or black colour. Spreads rapidly and total plantings can be destroyed within a week. Late blight symptoms The disease causes severe defoliation of tomatoes and [...]

Botrytis rot (Botrytis cinerea) Botrytis rot (Botrytis cinerea), also known as grey mould, is caused by the fungus Botrytis cinerea, and has become on the most serious diseases of tomato foliage and fruit. The fungus becomes established on dead leaves or stems at the base of the plant. A heavy grey growth of the fungus [...]

Bacterial speck, also known as Xanthomonas campestris pv. vesicatoria, Pseudomonas syringae pv. Tomato. Bacterial speck and spot are very difficult to distinguish from each other. However the control strategies are the same and both diseases attack the above ground organs of the plant. Bacterial speck symptoms Small water soaked lesions which develop during periods of rain, [...]