Bacterial spot is caused by Xanthomonas vesicatoria and is most noticeable in its effect on fruit. However it may also cause considerable injury to the foliage of seedlings and plants in the field. Bacterial spot occurs during rainy periods. Symptoms of bacterial spot Leaflets show small irregular dark spots of [...]
Fusarium wilt (Fusarium oxysporum) is one of the most damaging fungi that infects tomatoes. Fusarium wilt is a soil borne disease and infects both soil grown tomatoes and greenhouse tomatoes. During high temperatures the disease can cause significant crop damage but during low temperatures there is generally little damage. There [...]
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 [...]
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 [...]
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 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 [...]
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 [...]
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 [...]
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 [...]
