• Damping-off

  higher temperatures in the soil or irrigation water. Pythium aphanidermatum mostly occurs in young plants and damage is more extensive in young crops. Damage [...] irreversibly. In potted plants the flower buds fall off. The side roots rot and very little of the root system survives. On the border between air and soil or [...] are in a sub-optimal condition or suffer from stress, caused for example by too much water, too high or low temperatures or sudden fluctuations in temperature

• Early blight

  only known stage in all Alternaria species is the asexual stage. Conidia and mycelium overwinter in the soil and on crop residues and cause primary infection [...] three days later and sporulation within five days. Infection is both direct and through wounds and stomata. Spores are dispersed by wind and in some species [...] residues, weeds and volunteer plants. Use clean seed and propagation materials. Practice crop rotation, in particular when spores surviving in the soil are

• Angular leaf spot

  also introduced in a crop in new transplants. This bacterium is very resistant to desiccation and can survive well in dry leaves or leaves in the soil, but [...] cycle and appearance of Angular leaf spot Xanthomonas fragariae overwinters in plants and dead leaves, that become the primary source of infection in the [...] both passively and actively. Infection and disease development are favoured by temperatures around 20 °C during the day and cold nights, in combination with

• Bacterial wilt, brown rot

  survives well in water and in many different soil types and on alternative hosts like weeds. It invades the plants through wounds or stomata and then spreads [...] soil-borne disease and colonises the xylem, causing bacterial wilt and brown rot in a very wide range of potential host plants. Damage symptoms In potato, field [...] cycle and appearance of Bacterial wilt, brown rot Ralstonia solanacearum is a quarantine organism in Europe and considered a bioterrorist organism in the

• Bacterial canker of tomato

  the plants in greenhouse crops and by water in field crops, for example through splashes of rain or irrigation. Both in greenhouses and in the field, spraying [...] tested and disinfected seed Use only tested and certified seed potatoes Apply strict hygiene measures in greenhouse crops: remove infected plants in closed [...] protective clothing and gloves, disinfect tools and greenhouse structures Use a crop rotation in field crops of at least two years and alternate with a non-host

• Grey mould

  fungus in many environments. It survives in plant parts like bulbs and crop residues or as sclerotia (drought- and cold-resistant structures) in the soil [...] the lesion wilts and dies. In vegetables and strawberry, grey mould ( Botryotinia fuckeliana / Botrytis cinerea ) affects the fruit. In potted plants, the [...] plants or plant parts in a closed plastic bag In tomato: prune with a knife and not by hand, to avoid rugged, irregular wound surfaces In cucumber: remove dead

• Crazy roots, hairy roots, crown gall

  growth (crazy roots). In greenhouse vegetables, the roots overgrow the substrate and in severe epidemics the drippers get clogged. In tomato, excessive vegetative [...] rain and wind and by humans and tools. Until now, no bacteria have been isolated from crazy roots. This disease seems to be caused by a change in the hormonal [...] which are first white and later turn brown. Only Rhizobium radiobacter causes galls and tumours on underground plant parts and on the crown. Furthermore

• Apple scab

  petioles and fruits and sometimes on twigs and bud scales. The lesions are olive-green. When spores are produced, the lesions become grey and fluffy. The [...] unripe fruiting bodies in infected fallen leaves or in lesions on twigs. These unripe fruiting bodies, or pseudothecia ripen in winter and form ascospores. Depending [...] are released and repeat the cycle of infection of new plant parts and spore production. In autumn, the fungus produces new pseudothecia in leaves that have

• Verticillium wilt

  system usually stays mostly intact. In rose, branches die off from the top and purple brown stripes occur on the stem. In tomato, sometimes V-shaped lesions [...] periods (many years) in the soil as microsclerotia, small hard survival structures that can withstand high and low temperatures and dehydration. Verticillium [...] fungus and 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

• Black root rot of cucurbits

  away. Infection in the early stages of the crop results in stunted growth and smaller leaves with an intense green colour. Severe infection in this stage may [...] are slightly sunken and are mostly formed around the point of attachment of lateral roots and root hairs. The lesions may grow and encircle the root. The [...] sclerotioides survives in the soil and is a strong saprophytic competitor, which means it can rapidly colonize ‘clean’ or sterilized soil and substrate. It aggregates