• Angular leaf spot

  underside of the leaf. They enlarge to angular spots, often limited by the small veins. The distinctive feature is the way the lesions look when using different [...] 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 [...] 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 not

• Charcoal rot

  Cutting the roots may show the same discolouration of the internal tissues of the main roots. In most crops, necrotic lesions on the roots are the first [...] as microsclerotia. In corn stalks, survival of up to 1.5 years has been reported. The density of the microsclerotia in the soil is directly related to [...] by wilting, dropping of leaves and collapse of the entire plant. Life cycle and appearance of Charcoal rot The fungus survives in the soil and on crop residues

• Bacterial soft rot, bacterial stem rot

  rot is first noticed when plants wilt at the time of first harvest or after that. The pith disintegrates and the stem becomes hollow. Because of the bacterial [...] bacterial growth in the pith, the stem seems wet and slimy. Above or below the hollow stem the vascular tissue keeps its normal colour. On the fruits, lesions [...] leaves, but can grow in senescent leaves and from there grow through the petiole to the main stem through the xylem vessels. High humidity is required for disease

• Pea blight, leaf and pod spot

  ) causes foot rot in peas, whereas Ascochyta pisi does occur sometimes at the stem base but is not part of the foot rot syndrome in peas. Infected seeds [...] surrounded by a 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 [...] infection is purely seed-borne. Conidia and other fungal structures are transmitted on the outside of the seed coat and cause primary infection. The conidia

• Fusarium head blight or scab

  density. The foot of the plant is infected, either because the seedling was infected or by direct infection of the foot by overwintering inoculum. On the infected [...] 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 [...] ascospores. In general, most Fusarium specieshave a similar life cycle. Fusarium overwinters for many years in the soil and on crop residues of infected plants

• Crazy roots, hairy roots, crown gall

  crown gall The primary source of infection by Rhizobium rhizogenes has not yet been defined. The assumption is that the bacteria survive in the soil, but [...] caused by a change in the hormonal system of the plant resulting from the Rhizobium infection. Rhizobium rhizogenes puts a Ri-plasmid in the plant tissue and [...] disinfection of tools, drippers, gutters etc. Adjust the work order in greenhouses to fit with the hygiene protocol Disinfect the nutrient solution in order to

• Wheat bunt

  sporidia infect the wheat seedlings even before emergence and the fungi grow inside the plants to the growing tip. The fungi grow between the plant cells and [...] allowing the teliospores to fall to the ground. Additionaly, these teliospores contaminate healthy kernels, which in turn become a source of disease in the [...] Sowing winter crops early in the fall when temperatures are still above 15°C at the critical first 11 days reduces the risk of infection by Triticum tritici

• Phytophthora blight

  leaf wetness is required. Dispersal is by wind and rain causes the pathogen to be returned to the soil from infected plants. Dispersal in the soil happens [...] fungal growth on the leaves. The centre is grey-brown with a light-green edge. On the stem, elongated brown lesions occur, usually circling the stem. On potato [...] higher water content than is optimal for crop growth. Phytophthora overwinters in roots, infected tubers and bulbs or in the soil in different stages: as oospores

• Bacterial spot

  as they grow. The centre of the lesions may fall out as they become drier. Under humid conditions, the spots may merge with lesions on the petioles and [...] volunteer plants and crop debris Avoid waste piles in the vicinity of the greenhouse or field Resistant cultivars of pepper are available and should be used Prevent [...] green fruits. The specks grow into brown spots that look like scab. These spots may be surrounded by a halo. In pepper, the spots on the leaves are also

• Damping-off

  soil or 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 [...] 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 [...] at the start by using higher substrate blocks for the seedlings. In field crops: Avoid the use of fields with inadequate drainage or improve the drainage