• Cottony soft rot

  January 1, 1970

  cottony soft root, is a plant pathogenic fungus. It has a very wide range of host plants. Damage symptoms The first symptoms of a cottony soft root ( S [...] Germination and infection mostly take place at high soil water content over a prolonged period of time. The sclerotia germinate directly and form mycelium [...] dark sclerotia. The fungus also infects seeds and tubers, thereby creating a source of infection for the next crop. The dispersal to neighbouring plants

• Black root rot of cucurbits

  January 1, 1970

  infection in this stage may kill the plants. In case of a less severe infection, the vines may wilt at a late stage of the crop, but when water supply is in [...] General Phomopsis sclerotioides is a plant pathogen infecting cucurbits, causing black root rot of cucurbits. Damage symptoms Phomopsis sclerotioides causes [...] causes grey-black spots with a dark demarcation line on cucumber roots. The lesions are slightly sunken and are mostly formed around the point of attachment

• Loose smut of wheat

  January 1, 1970

  first sign of infection is the appearance of a smutted ear. Instead of normal tissue, the ear contains a mass of olive-brown smut spores. Life cycle and [...] within a day and infect the inner tissues of the newly infected seed. During maturation of the seed, the mycelium becomes thick-walled and swollen as a dormant [...] General Ustilago nuda f.sp. tritici is a basidiomyceteous fungus that affects wheat. It is also known as loose wheat smut, or loose smut of wheat. Damage

• Loose smut of barley

  January 1, 1970

  first sign of infection is the appearance of a smutted ear. Instead of normal tissue, the ear contains a mass of olive-brown smut spores. Life cycle and [...] within a day and infect the inner tissues of the newly infected seed. During maturation of the seed, the mycelium becomes thick-walled and swollen as a dormant [...] General Ustilago nuda f.sp. hordei affects barley and can destroy a large proportion of the crop. It is also known as barley smut, or loose smut of barley

• Downy mildew of Cucurbits

  January 1, 1970

  prevent Downey mildew Choose resistant cultivars Use a wide crop rotation with non-host crops Prevent a humid microclimate. Achieve this by lowering crop [...] General Pseudoperonospora cubensis is a plant pathogen causing downy mildew on cucurbit crops like cucumber, cantaloupe, pumpkin, watermelon and squash [...] living plant cells. The pathogens continue to grow inside the leaves and after a while new spore-bearing structures are protruding from the stomata. Because

• Black rot of carrots

  January 1, 1970

  during harvest (in potato and carrot). Post-harvest storage at 0-1 o C. A. brassicae and A. brassicicola : adjust the sowing date to avoid conditions conducive [...] Alternaria radicina ) causes death of seedlings and dark brown lesions with a yellow halo on leaves, growing into crown rot. Infection of carrots during [...] appearance of Black rot of carrots Black rot of carrots ( Alternaria radicina ) is a seed-transferred carrot disease. The seeds are the main source of primary infection

• Early blight

  January 1, 1970

  during harvest (in potato and carrot). Post-harvest storage at 0-1 o C. A. brassicae and A. brassicicola : adjust the sowing date to avoid conditions conducive [...] occur on leaves. Those spots then turn into dark brown angular lesions with a yellow halo restricted by leaf veins. Lesions can easily rupture. Other symptoms [...] 2-4 °C up to 28-30 °C (optimum temperatures lie between 15 and 28 °C) and at a relative humidity (RH) of over 90% or when the leaves are wet. Small differences

• Pierce's disease of grapevine

  January 1, 1970

  spreads over the leaf from the margin and is marked by a chlorotic band. In the beginning, only a few leaves per branch are showing symptoms, but later [...] General Xylella fastidiosa is a gram-negative bacterium which is limited to xylem tissue. It has many hosts, many of which show minor or no symptoms. More [...] symptoms Grapevines: Primary infection of leaves results in leaf scorch. Part of a green leaf suddenly dies and turns brown with adjacent tissue turning yellow

• Black sigatoka disease

  January 1, 1970

  one month old. The symptoms run parallel to the veins. Within a few days, the spots become a few centimetres in size and turn brown with light grey centres [...] brown and ultimately dies. In cases of severe infection leaves may die within a few weeks. Because of the lack of leaf tissues, fruit maturity is hampered [...] germinate within two or three hours under humid conditions, but infection takes a minimum of two or three days under optimal conditions (humidity close to saturation

• Grapevine powdery mildew

  January 1, 1970

  Grapevine powdery mildew (Erysiphe necator) is a widespread fungal disease that poses a serious threat to commercial viticulture worldwide. The pathogen [...] it does not require free water (such as rain or dew) to infect, making it a persistent threat throughout the entire growing season. Early detection and [...] grey powdery mycelium. As the infection intensifies, affected leaves suffer a marked reduction in photosynthetic capacity, while shoots and flowers exhibit