• 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

• Apple collar rot

  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 Phytophthora cactorum is a plant pathogen that causes root rot, rhizome rot of strawberry, apple rot, apple collar rot and crown rot. It has an [...] thrive at soil temperatures between 15 and 23 °C and higher water content than is optimal for crop growth. Phytophthora overwinters in roots, infected tubers

• 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

• Crazy roots, hairy roots, crown gall

  yet been defined. The assumption is that the bacteria survive in the soil, but it is possible that first infection is from the propagation material. Infection [...] Agrobacterium rhizogenes and Agrobacterium rubi, n ow the first part of the name is changed to Rhizobium. Rhizobium rhizogenes or Rhizobium radiobacter causes [...] tumours on underground plant parts and on the crown. Furthermore, infection is characterized by excessive root growth (crazy roots). In greenhouse vegetables

• Wheat bunt

  tritici and Tilletia laevis only differ in one gene and easily hybridize. There is debate whether they should indeed be considered separate species, since they [...] 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 [...] kernels, which in turn become a source of disease in the next season. Infection is strongly correlated to temperature and precipitation in the first 11 days

• Gummy stem blight

  General Mycosphaerella cucumis (Didymella bryoniae) is a fungal plant pathogen that causes gummy stem blight. Damage symptoms Mycosphaerella cucumis in [...] round and extending lesions may occur. In cucumber, the most important symptom is internal fruit rot, which can only be recognized from the outside by the small [...] ascospores and asexual conida simultaneously. The spores germinate when free water is present on the plant, at high relative humidity (RH) and on wounds. Leaves

• Bacterial spot

  development is favoured by temperatures between 24 and 30 °C and high precipitation due to rain, fog or overhead irrigation. Infection is through stomata [...] General Xanthomonas vesicatoria is a bacterium that causes bacterial leaf spot on peppers and tomatoes. Damage symptoms Xanthomonas vesicatoria in tomato [...] stomata and wounds. The dispersal is in windblown water drops, mechanical means such as clipping and handling and aerosols. Many isolates are resistant to

• Damping-off

  General Pythium is considered a ‘weak pathogen’, meaning that it can usually only affect plants that are in a sub-optimal condition or suffer from stress [...] irrigation water. Pythium aphanidermatum mostly occurs in young plants and damage is more extensive in young crops. Damage symptoms Pythium affects roots, in [...] substrate the plant turns brown. A typical symptom of a Pythium infection is the easy stripping of the skin from the root cortex with a finger nail. Life

• Loose smut of wheat

  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 [...] tritici remains invisible until head emergence. The first sign of infection is the appearance of a smutted ear. Instead of normal tissue, the ear contains

• Black rot of carrots

  General The only known stage in all Alternaria species is the asexual stage. Conidia and mycelium overwinter in the soil and on crop residues and cause [...] 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 [...] s occur between species, but in general, the risk of Alternaria infection is larger under quite warm and humid conditions. Infection may take place within