• Apple scab

  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 [...] appearance of Apple scab Venturia inaequalis overwinters in the form of unripe fruiting bodies in infected fallen leaves or in lesions on twigs. These unripe [...] 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

• Early blight

  stage in all Alternaria species is the asexual stage. Conidia and mycelium overwinter in the soil and on crop residues and cause primary infection of the [...] 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 [...] early blight of potato and early blight of tomato, which presents itself as spots on leaves, petals and stems. These spots can be distinguished by the dark

• Verticillium wilt

  caused by Fusarium . The root system usually stays mostly intact. In rose, branches die off from the top and purple brown stripes occur on the stem. In tomato [...] high and low temperatures and dehydration. Verticillium dahliae also survives as hyphae (mycelium) in crop residues. The fungus infects the roots of plants [...] the plant produces gum in the vessels. The presence of both the fungus and the gum causes the xylem vessels to get blocked, which in turn causes the plant

• Bacterial canker of tomato

  seedlings by touching the plants in greenhouse crops and by water in field crops, for example through splashes of rain or irrigation. Both in greenhouses [...] brown centre. In potato, the disease usually only occurs in the second half of the season. The first symptoms are wilting of the lower leaves and subsequent [...] the name ring rot. Life cycle and appearance of Bacterial canker of tomato Clavibacter is seed-borne and tuber-borne and primary infection is mostly from

• Root and crown rot of strawberry

  New diseases in strawberry have been ascribed to Pestalotiopsis clavispora in the case of root and crown rot (of strawberry), first found in The Netherlands [...] Netherlands, and Pestalotiopsis longisetula in the case of leaf spots, such as leaf spot of strawberry and fruit rot reported mainly from Brazil. The genus is [...] necrotic areas in crown and root of strawberry. Plant development is slow, growth is retarded and rooting is poor. Transplants look weak and may die. It is

• Gummy stem blight

  conidiospores by water drops, tools and hands of workers. The ascospores are the main source of dispersal of disease upwards in the crop and the conidia [...] after opening in areas suspected of disease (only feasible in high-wire crops) Pick and remove dead and diseased leaves Prevent plant diseases by optimizing [...] narrowing of the tip of the mature fruits. The symptoms on stems, leaves and inside the fruits may occur together or individually. Life cycle and appearance

• Angular leaf spot

  appearance of Angular leaf spot Xanthomonas fragariae overwinters in plants and dead leaves, that become the primary source of infection in the spring. The bacteria [...] 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 [...] are dispersed by rain, irrigation water or handling of the plants. Infection of the plants happens both passively and actively. Infection and disease development

• Phytophthora blight

  tomato, potato blight and late / early blight of potato. Damage symptoms Phytophthora causes root rot, seedling damping off and rot of stems, bulbs, tubers [...] a period of mass starvation caused by this disease which ravaged potato crops throughout Europe during the 1840s. Life cycle and appearance of Phytophthora [...] optimal for crop growth. Phytophthora overwinters in roots, infected tubers and bulbs or in the soil in different stages: as oospores (sexual overwintering

• Pierce's disease of grapevine

  appearance of Pierce's disease of grapevine The bacteria live in xylem vessels in roots, stems and leaves and multiply. The plant may react by producing gum [...] die. This happens faster in younger vines than in older ones and faster in susceptible cultivars (within 2-3 years) than in more tolerant cultivars, which [...] the plant species: in peach, bacteria are found in high numbers in the roots, whereas in plum, high numbers are found in leaves and fruits. The bacteria

• 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 [...] typical symptom of a Pythium infection is the easy stripping of the skin from the root cortex with a finger nail. Life cycle and appearance of Damping-off