Verticillium wilt

the gum causes the xylem vessels to get blocked, which in turn causes the plant to wilt. Spores may be wind-dispersed to new hosts. In the senescent tissue [...] leaves are pale-green, then orange-yellow. In the beginning the plant seems to recover at night. The symptoms may occur only in parts of the plant. Cutting [...] The spread of the fungus by mycelium growth is limited. Dispersal from plant to plant takes place via water, soil particles, tools, etc. Verticillium can

Bacterial spot

and handling and aerosols. Many isolates are resistant to copper-containing pesticides. How to prevent Bacterial spot Use clean propagation material and [...] surrounded by a 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 [...] is favoured by temperatures between 24 and 30 °C and high precipitation due to rain, fog or overhead irrigation. Infection is through stomata and wounds

Black rot of carrots

infection and this may lead to death of seedlings. From the primary infection of leaves, this type of carrot disease can spread to the flowers (especially [...] A. brassicae and A. brassicicola : adjust the sowing date to avoid conditions conducive to infection. In greenhouses: avoid high RH. Prevent plant diseases [...] several years, in the case of black rot of carrots ( Alternaria radicina ) up to 8 years. Damage symptoms Black rot of carrots ( Alternaria radicina ) causes

Early blight

specific symptoms. Damage symptoms Alternaria solani causes small green to dark brown spots to occur on leaves. Those spots then turn into dark brown angular lesions [...] of leaves, Alternaria solani can spread to the flowers (especially dangerous in crops for seed production) and to the crown. Sporulation of Alternaria occurs [...] A. brassicae and A. brassicicola : adjust the sowing date to avoid conditions conducive to infection. In greenhouses: avoid high RH. Prevent plant diseases

Downy mildew of Cucurbits

mildew Pathogens causing downy mildew are not fungi but Oomycetes and related to Pythium and Phytophthora. They survive as oospores. From these oospores or [...] the optimum temperature is around 15 o C and the closer the temperature is to this, the shorter the leaf wetness period that is required. Inside the plant [...] can take up nutrients from the living plant cells. The pathogens continue to grow inside the leaves and after a while new spore-bearing structures are

Gummy stem blight

How to prevent Gummy stem blight Before cropping: Remove all crop debris and disinfect the greenhouse Choose a cultivar that is less susceptible to internal [...] Calcium nutrition hardens the cell walls and makes it harder for the fungi to enter the leaves Pick flowers within two days after opening in areas suspected

Cottony soft rot

source of infection for the next crop. The dispersal to neighbouring plants is by mycelial growth. How to prevent Cottony soft rot Practice dry cultivation/be [...] occur on stems but also on leaves, fruits and pods. Root infection often leads to premature wilting and death of plants. Life cycle and appearance of Cottony

Apple scab

fall off prematurely. The plants’ defence mechanism is to produce corky rings around the lesions to prevent further invasion of tissue by the fungus. Late [...] temperatures this increases to 12-28 hours of leaf wetness for successful infection. Conidia also need water for germination. How to prevent Apple scab Use [...] subsequently released when they become wet. The ascospores are wind-dispersed to the fruit trees and will germinate if free water is available. They infect

Loose smut of wheat

Infection mostly occurs before pollination and within one to two days after pollination. How to prevent Loose smut of wheat Use clean seed: Apply systemic

Loose smut of barley

Infection mostly occurs before pollination and within one to two days after pollination. How to prevent Loose smut of barley Use clean seed: Apply systemic