Pierce's disease of grapevine

plants to wilt. Transport to different plant parts depends on the plant species: in peach, bacteria are found in high numbers in the roots, whereas in plum [...] 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 [...] Infection becomes systemic more rapidly in young trees than in older trees. In the latter, it may stay limited to certain branches. When the leaves mature

Southern blight

was first observed in tomato crops in Florida in 1892, and it has been regularly reported as causing rotting to the root and stem in tomato plants. Significant [...] generally close to the surface of the stem. In favourable conditions, the sclerotia can germinate in two forms, hyphal or eruptive, causing infection in the plants [...] Significant losses occur in soils infested by the pathogen, which have a light texture and humidity close to field capacity. In the southern USA, losses can

Powdery mildew

and makes it harder for the fungi to enter the leaves To reduce chances of powdery mildew in greenhouses, it is advised to first ventilate by only opening [...] colonies mostly occur in these crops. In covered roses, the colonies appear first and foremost on the upper side of the leaves. In most crops, the white [...] fairly similar in all plant-pathogen combinations. The symptoms are white fluffy colonies, first and foremost on the upper side of the leaf. In severe epidemics

Fusarium spp.

also produce ascospores. In general, the life cycle of different Fusarium species is similar. Fusarium overwinters for many years in the soil, and on crop [...] effectively with hot water) Use clean substrate in greenhouse crops Disinfect tools, machinery and irrigation water in greenhouses Prevent plant stress Ensure [...] the Fusarium solani species complex (FSSC) are capable of causing disease in many agriculturally important crops Damage symptoms of Fusarium spp. Fusarium

Black rot of carrots

lead to death of seedlings. From the primary infection of leaves, this type of carrot disease can spread to the flowers (especially dangerous in crops [...] brassicae and A. brassicicola : adjust the sowing date to avoid conditions conducive to infection. In greenhouses: avoid high RH. Prevent plant diseases by [...] 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

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 [...] allow the disease to spread to neighbouring plants. The zoospores disperse via water. Therefore, this disease spreads most rapidly in wet conditions with [...] survive very well in the soil or substrate in the absence of plants. Many species are entirely saprophytic, so these do not harm plants. How to prevent Damping-off

Charcoal rot

°C and dry conditions. In field crops in temperate regions it is therefore not a problem. How to prevent Charcoal rot Plant in fields with no history of [...] tissue layer) to orange-brown to dark brown. Cutting the roots may show the same discolouration of the internal tissues of the main roots. In most crops, [...] Charcoal rot The fungus survives in the soil and on crop residues as microsclerotia. In corn stalks, survival of up to 1.5 years has been reported. The

Angular leaf spot

source of infection in the spring. The bacteria are also introduced in a crop in new transplants. This bacterium is very resistant to desiccation and can [...] can survive well in dry leaves or leaves in the soil, but not independantly in the soil. Under humid conditions, bacteria ooze from the lesions on the leaves [...] found in strawberry. Damage symptoms Xanthomonas fragariae initially causes small, water-soaked lesions on the underside of the leaf. They enlarge to angular

Early blight

sporulation. Species may differ in specific symptoms. Damage symptoms Alternaria solani causes small green to dark brown spots to occur on leaves. Those spots [...] of leaves, Alternaria solani can spread to the flowers (especially dangerous in crops for seed production) and to the crown. Sporulation of Alternaria occurs [...] brassicae and A. brassicicola : adjust the sowing date to avoid conditions conducive to infection. In greenhouses: avoid high RH. Prevent plant diseases by

Bacterial canker of tomato

are taken to eradicate the infection. In tomato, growers must either destroy the infected crop entirely or, if the crop is old, only the plants in the infected [...] cankers to form. On tomato leaves, water-soaked lesions occur, usually white with a brown centre. In potato, the disease usually only occurs in the second [...] infected propagation material. It spreads to other seedlings by touching the plants in greenhouse crops and by water in field crops, for example through splashes