• Pea blight, leaf and pod spot

  dark brown to red-brown border. The first infection is often on the primary leaves. The fungus is seed borne and thus also causes post- and pre-emergence [...] two-celled conidia are exuded. Secondary infection is by splash dispersal of these conidia. There is no known sexual stage. Ascochyta fungi develop most [...] General Ascochyta pisi is a fungal plant pathogen that causes A scochyta blight on pea (leaf blight or pea blight) and lesions of stems, leaves, and pods

• Black root rot of cucurbits

  adverse conditions for years in the soil, but little else is known about the life cycle. The fungus is dispersed by water, air and soil particles. How to prevent [...] General Phomopsis sclerotioides is a plant pathogen infecting cucurbits, causing black root rot of cucurbits. Damage symptoms Phomopsis sclerotioides causes [...] pseudostromata: dark coloured tissue that looks like black stripes. The disease is usually restricted to a few of the roots but in severe cases all roots may

• Phytophthora blight

  infection is either by germinating sporangia or by zoospores produced in the sporangia. For germination on above-ground plant parts, leaf wetness is required [...] General Late blight (Phytophthora infestans f.sp. infestans) is also known as Phytophthora blight, tomato blight, early / late blight tomato, potato blight [...] with vague borders and white fluffy fungal growth on the leaves. The centre is grey-brown with a light-green edge. On the stem, elongated brown lesions occur

• Powdery mildew

  General Powdery mildew is a fungal disease that is caused by many different species of fungi such as Erysiphe, Podosphaera, Oïdium, Leveillula. Damage [...] fungus causing powdery mildew is extremely sensitive to water and ‘hides’ on the underside of the leaves. Therefore, this is where the colonies mostly occur [...] epidemic is fastest at 18-25 °C. High relative humidity (RH) promotes germination of spores but inhibits spore production, so the net effect of the RH is very

• Fusarium head blight or scab

  General Fusarium is a group of soil-borne fungi with many different species. Fusarium is widespread and can infect a range of host crops. Many species [...] mycelium cells) or mycelium. Survival is also possible on seed, greenhouse structures, tools and machinery. Primary infection is either seed-borne or takes place [...] overwinters as chlamydospores and ascospores in crop residues. Primary infection is from this inoculum or from infected seed. Infected seed doesn’t germinate

• Bacterial canker of tomato

  tubers. This discolouration is round, hence the name ring rot. Life cycle and appearance of Bacterial canker of tomato Clavibacter is seed-borne and tuber-borne [...] General Clavibacter is a quarantine organism in Europe, which means that strong efforts are used to prevent the bacterium from entering. When the occasional [...] occasional infection is found, strict measures are taken to eradicate the infection. In tomato, growers must either destroy the infected crop entirely or,

• Pierce's disease of grapevine

  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 [...] In peach, the canopy of infected plants is compact and umbrella-like due to the shorter internodes. The foliage is denser and the leaves are a darker green [...] smaller and their sugar content is higher. The early blossoming and fruit set in peach does not occur in citrus, there is no difference between infected

• Angular leaf spot

  veins. The distinctive feature is the way the lesions look when using different light sources: when reflected light is used, the lesions look dark green [...] General Xanthomonas fragariae is a leaf spot disease found in strawberry. Damage symptoms Xanthomonas fragariae initially causes small, water-soaked lesions [...] green, but when transmitted light is used, they are translucent. When conditions are humid, a viscous bacterial exudate forms on the underside of the leaf

• Bacterial soft rot, bacterial stem rot

  subsp. carotovora has recently been renamed Pectobacterium carotovora . It is one of the pectolytic bacteria causing extensive bacterial rots (bacterial [...] Pectobacterium carovora causes bacterial stem rot as well as soft rot. Stem rot is first noticed when plants wilt at the time of first harvest or after that [...] bacterial stem rot Erwinia carotovora subsp. carotovora or Pectobacterium carovora is very common, but does not often reach epidemic population densities. It can

• Dwarf bunt

  General Tilletia controversa is a plant pathogen. It is a fungus known to cause the smut disease TCK smut in soft white and hard red winter wheats, as [...] some or on all spikelets, showing the bunt (smut spore) they contain, which is larger than a normal kernel. The bunt balls are grey-brown. They rupture at [...] suitable host for as long as ten years. Seed-borne transmission does occur, but is less important from an epidemiological point of view. The teliospores germinate