• Black root rot of cucurbits

  cucurbits. Damage symptoms Phomopsis sclerotioides causes grey-black spots with a dark demarcation line on cucumber roots. The lesions are slightly sunken [...] The roots become yellow-brown to black and ultimately die. Black lesions with fruiting bodies occur more commonly at temperatures of approximately 20 °C [...] the early stages of the crop results in stunted growth and smaller leaves with an intense green colour. Severe infection in this stage may kill the plants

• Cottony soft rot

  In the mycelium, big, dark sclerotia are formed. They can easily be seen with the naked eye and look like rat droppings. The symptoms may occur on stems [...] or on the ground. Sclerotia germinate at temperatures between 4 and 26 °C with an optimum between 13 and 15 °C. Germination and infection mostly take place [...] the host cells. On the infected plant tissue white, fluffy mycelium occurs with new dark sclerotia. The fungus also infects seeds and tubers, thereby creating

• Phytophthora blight

  causes water-soaked lesions with vague borders and white fluffy fungal growth on the leaves. The centre is grey-brown with a light-green edge. On the stem [...] the overwintering structures which infect the host. Zoospores are spores with flagellae which enable them to move through water. Infection is usually from [...] and new sporangiophores (structures containing sporangia, a type of spores) with sporangia are formed that protrude through the stomata. Secondary infection

• Bacterial spot

  of) leaf surfaces and may enlarge into dark brown lesions with a light brown centre. As with powdery mildew infection, pepper plants shed the leaves that [...] fall out as they become drier. Under humid conditions, the spots may merge with lesions on the petioles and stems and form long dark streaks. On fruits, [...] halo. In pepper, the spots on the leaves are also round and small to start with and slightly raised from the leaf surface. They occur on the abaxial (underside

• Black leg of seedlings

  Pythium infection is the easy stripping of the skin from the root cortex with a finger nail. Life cycle and appearance of Black leg of seedlings Pythium [...] sporangia from which subsequently zoospores are produced. Zoospores are spores with flagellae, which enable the spores to move through water. The zoospores are [...] through other similarly damaged spots. On the infected plant, new sporangia with zoospores are formed, that allow the disease to spread to neighbouring plants

• Damping-off

  Pythium infection is the easy stripping of the skin from the root cortex with a finger nail. Life cycle and appearance of Damping-off Pythium belongs to [...] sporangia from which subsequently zoospores are produced. Zoospores are spores with flagellae, which enable the spores to move through water. The zoospores are [...] through other similarly damaged spots. On the infected plant, new sporangia with zoospores are formed, that allow the disease to spread to neighbouring plants

• Apple collar rot

  system and black discolouration of the roots. On the foot, dark brown lesions with sharp borders occur. Above the graft and on leaves, dark brown, irregular [...] the overwintering structures, which infect the host. Zoospores are spores with flagellae, which enable them to move through water. Infection is usually [...] and new sporangiophores (structures containing sporangia, a type of spores) with sporangia are formed, that protrude through the stomata. Secondary infection

• Pierce's disease of grapevine

  example, transfer from infected plum trees with high bacterial levels in the leaves to neighbouring peach trees with the bacteria mainly in the roots is much [...] results in leaf scorch. Part of a green leaf suddenly dies and turns brown with adjacent tissue turning yellow or red. This desiccation spreads and the whole [...] stunted. When the infection becomes chronic, the leaves become distorted with interveinal chlorosis and the shoots get shorter internodes. Infected vines

• Bacterial canker of tomato

  crop entirely or, if the crop is old, only the plants in the infected area, with a substantial buffer zone. Replanting can only take place after thorough [...] cankers to form. On tomato leaves, water-soaked lesions occur, usually white with a brown centre. In potato, the disease usually only occurs in the second [...] expansion of the wilt upwards. Cutting the stem at the foot shows whitish ooze with bacteria in the case of C lavibacter infection, but other than that the disease

• Brown root rot, corky root rot

  gradually break off. The corky areas often occur as horizontal bands on the roots with lengthwise cracks. No discoloration is present in the xylem tissues which [...] temperatures above 20 °C. The fungus produces pycnidia containing conidiophores with conidia and microsclerotia. Spread happens through dispersal of soil particles [...] rot, corky root rot Field crops: Fumigate the soil Practise crop rotation with non-host crops Delay planting in the spring until soil temperatures are higher