Early blight

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 [...] 90% or when the leaves are wet. Small differences in optimum temperature occur between species, but in general the risk of Alternaria infection is larger [...] seed and propagation materials. Practice crop rotation, in particular when spores surviving in the soil are the main source of infection. Especially wheat

Angular leaf spot

overwinters in plants and dead leaves, that become the primary source of infection in the spring. The bacteria are also introduced in a crop in new transplants [...] resistant to desiccation and can survive well in dry leaves or leaves in the soil, but not independantly in the soil. Under humid conditions, bacteria ooze [...] during the day and cold nights, in combination with high humidity or presence of water. These conditions occur mostly in the spring if it rains or when

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 [...] 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 [...] Damage symptoms Pythium affects roots, in particular those of seedlings. Infected plants lag in growth. Seedlings start falling over, also called ‘damping-off’

Bacterial wilt, brown rot

quarantine organism in Europe and considered a bioterrorist organism in the United States. It is a commonly found soil-inhabitant in tropical and subtropical [...] for Race 3 is 27 °C, which makes it more dangerous in temperate regions. It survives well in water and in many different soil types and on alternative hosts [...] xylem, causing bacterial wilt and brown rot in a very wide range of potential host plants. Damage symptoms In potato, field symptoms of Ralstonia solanacearum

Botrytis

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 [...] 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 [...] lesion wilts and dies. In vegetables and strawberry, grey mould ( Botryotinia fuckeliana / Botrytis cinerea ) affects the fruit. In potted plants, the cuttings

Downy mildew of rose

and this causes the plant to fall over. In cabbage the stem is also infected in severe epidemics. In blackberry, red stripes may occur on the stems and petioles [...] sporulation is relatively low, in general between 10 and 20 °C. Late in the season new overwintering oospores are produced and buried in the soil with crop residues [...] white and later turns grey-brown. This is, in fact, the sporulation of the pathogens extruding from the stomata. In lettuce, the foot is infected first and

Bacterial soft rot, bacterial stem rot

survive as epiphytic bacteria on various plants or in the soil in low densities. It has also been found in the gut of insects, possibly spreading from decaying [...] also be found as secondary pathogen in plants that are infected by other pathogens. The bacteria that causes black leg in potato is a different subspecies [...] extensive bacterial rots (bacterial soft rot, bacterial stem rot). Damage symptoms In tomato, Erwinia carotovora subsp. carotovora or Pectobacterium carovora causes

Fusarium wilt

effectively with hot water) Use clean substrate in greenhouse crops Disinfect tools, machinery and irrigation water in greenhouses Prevent stress for the plants [...] vascular wilt, root rot, foot and stem rot, leaf lesions, fruit rot, head blight in cereals and post-harvest decay. Fusarium oxysporum is the species causing [...] discolouration of the xylem vessels which can be seen when the stems are cut. In banana, whole plantations may die and the soil may not be suitable for planting

Cottony soft rot

Sclerotinia sclerotiorum ) overwinters as sclerotia and mycelium in dead and living plant material in or on the ground. Sclerotia germinate at temperatures between [...] mycelium grows on the lesions, giving this disease its name cottony soft rot. In the mycelium, big, dark sclerotia are formed. They can easily be seen with [...] and the roots, whereas the ascospores infect the above-ground plant parts. In greenhouses, usually only mycelium is produced by the germinating sclerotia

Black sigatoka disease

parallel to the veins. Within a few days, the spots become a few centimetres in size and turn brown with light grey centres. These spots enlarge further and [...] and dies. Lesions merge and the whole leaf turns brown and ultimately dies. In cases of severe infection leaves may die within a few weeks. Because of the [...] least stack them, so the spores cannot be discharged from the lower leaves in the stack Use under-canopy (drip) irrigation to reduce splash dispersal Lower