Bacterial wilt, brown rot

vascular stem tissue is coloured brown and when the stem is cut, bacterial slime oozes from the wound. This is the way to distinguish it from Verticillium or [...] into the xylem vessels. In potato, it is tuber-borne. Spread from plant to plant results from bacteria moving from the roots of infected plants to neighbouring [...] grey-brown. This disease can be distinguished from Clavibacter by the bacterial slime produced from wounds, which is not seen in Clavibacter -infected plants

Damping-off

the oospores is stimulated by exudates from roots of a susceptible host nearby. The oospores germinate and form so-called sporangia from which subsequently [...] General Pythium is considered a ‘weak pathogen’, meaning that it can usually only affect plants that are in a sub-optimal condition or suffer from stress, caused [...] 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. Life cycle and appearance

Downy mildew of Cucurbits

growth appears which is first white and later turns grey-brown. This is actually the sporulation of the pathogens extruding from the stomata. Life cycle [...] germination free water is required. For most downy mildews, the optimum temperature is around 15 o C and the closer the temperature is to this, the shorter [...] period that is required. Inside the plant, the pathogens produce haustoria, small organs with which the pathogen can take up nutrients from the living plant

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 [...] occur at the side of the stem. Life cycle and appearance of Early blight From the primary infection of leaves, Alternaria solani can spread to the flowers [...] production) and to the crown. Sporulation of Alternaria occurs at temperatures from 2-4 °C up to 28-30 °C (optimum temperatures lie between 15 and 28 °C) and

Cabbage leafroller

appearance of Cabbage leafroller An adult female is 12 mm long and is ochre-yellow with darker markings. The male is slightly smaller and slimmer, more clearly [...] General The cabbage leafroller (Clepsis spectrana) is native to North-West Europe. It is a highly polyphagous species causing damage to field grown cabbage [...] prothoracic shield. The body is drab brown with lateral stripes that are sometimes light in colour. The ventral surface is lighter than the dorsal, with

Diamond back moth

xylostella) is suggested to have its origin in Europe, South Africa or East Asia, but is now present wherever its cruciferous hosts exist and it is considered [...] species. It is highly migratory and wind-borne adults can travel long distances to invade crops in other regions. Damage symptoms The caterpillar is a surface [...] pupa is pinkish-white to pinkish-yellow and changes to brown before adult emergence. The adult of the diamond back moth (Plutella xylostella) is slender

Phytophthora blight

through water. Infection is usually from the root to the foot, but direct infection of the foot also occurs. Exudates leaking from growing root tips promote [...] infection is either by germinating sporangia or by zoospores produced in the sporangia. For germination on above-ground plant parts, leaf wetness is required [...] required. Dispersal is by wind and rain causes the pathogen to be returned to the soil from infected plants. Dispersal in the soil happens via water, since

Aphidius matricariae

wasp Aphidius matricariae Aphidius matricariae is a parasitic wasp belonging to the family Braconidae and is widely recognized for its role in biological [...] aphids . This small wasp is a valuable natural enemy in both agricultural and horticultural settings. Aphidius matricariae is used for the control of the [...] matricariae is available in a bottle ( Aphipar-M ). Spread the material on rock wool slabs or in Diboxes Make sure the material remains dry and is not moved

Root rot of carrot

fungus appears to prefer older tissue. In the field, the disease is difficult to distinguish from both Cercospora and Alternaria dauci . Cercospora prefers younger [...] or alternate hosts and transfer to annual crops. As far as is known, Daucus carota (carrot) is the only host plant of the fungus. How to prevent root rot [...] pathogens in Northwest Europe. Damage symptoms Rhexocercosporidium carotae is a slow-growing fungus that can infect both roots and foliage. The infection

Bacterial canker of tomato

General Clavibacter is a quarantine organism in Europe, which means that strong efforts are used to prevent the bacterium from entering. When the occasional [...] of C lavibacter infection, but other than that the disease is difficult to distinguish from wilting caused by other pathogens. On potato tubers, first [...] tubers. This discolouration is round, hence the name ring rot. Life cycle and appearance of Bacterial canker of tomato Clavibacter is seed-borne and tuber-borne