Rhizoctonia solani

rain, water, machinery and tools and in soil particles and via movement of plant parts. The fungus grows from plant to plant and from the soil upward, therefore [...] parts in contact with the soil and from there can grow upward. Lesions are brown and rot on fruits is brown, water-soaked and sunken. Late infection causes [...] seen, but they vary in size and colour and are therefore not a good feature to determine the cause of the disease. Life cycle and appearance of Thanatephorus

Black leg of seedlings

flower buds fall off. The side roots rot and very little of the root system survives. On the border between air and soil or substrate the plant turns brown [...] finger nail. Life cycle and appearance of Black leg of seedlings Pythium belongs to the Oomycetes, a separate group of microorganisms and is therefore not a [...] immediately after planting. Avoid cold and excessive warm irrigation water. Keep the water content of the substrate below 70% and ensure good drainage Disinfect

Bacterial canker of tomato

on stems, leaves and fruits. Leaves and shoots wilt. On the lower leaves, blister-like white lesions occur, which later turn brown and may merge. The leaves [...] 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 [...] protective clothing and gloves, disinfect tools and greenhouse structures Use a crop rotation in field crops of at least two years and alternate with a non-host

Crazy roots, hairy roots, crown gall

which are first white and later turn brown. Only Rhizobium radiobacter causes galls and tumours on underground plant parts and on the crown. Furthermore [...] break open, releasing many bacteria. These are dispersed by rain and wind and by humans and tools. Until now, no bacteria have been isolated from crazy roots [...] roots, hairy roots and crown gall. Damage symptoms The four pathogenic Rhizobium species cause different symptoms, like galls, tumours and excessive root growth

Gummy stem blight

feasible in high-wire crops) Pick and remove dead and diseased leaves Prevent plant diseases by optimizing plant potential and crop resilience. [...] mature fruits. The symptoms on stems, leaves and inside the fruits may occur together or individually. Life cycle and appearance of Gummy stem blight Mycosphaerella [...] Mycosphaerella cucumis survives in crop debris and produces the sexual ascospores and asexual conida simultaneously. The spores germinate when free water is

Grey mould

infected after abortion and then provide a large amount of inoculum Extra Silicon and/or Calcium nutrition hardens the cell walls and makes it harder for the [...] environments. It survives in plant parts like bulbs and crop residues or as sclerotia (drought- and cold-resistant structures) in the soil. Damage symptoms [...] lesions. The symptoms on fruits, flowers and on various parts of potted plants often only become visible during and after cold storage. In lettuce, grey mould

Powdery mildew

apple, pear, outdoor grown rose and other Rosaceae , the fungus causing powdery mildew is extremely sensitive to water and ‘hides’ on the underside of the [...] mildew fungi and especially in greenhouse crops they don’t play a role in the epidemics. Fungal spores germinate on the leaf surface and the germ tubes [...] tubes grow and branch out on the leaf surface. Small structures are produced, the haustoria, from which the fungus penetrates the plant cell and takes up nutrients

Fusarium wilt

different species. Fusarium is widespread and can infect a range of host crops. Many species are considered weak pathogens and can only infect wounded or stressed [...] fungi cause vascular wilt, root rot, foot and stem rot, leaf lesions, fruit rot, head blight in cereals and post-harvest decay. Fusarium oxysporum is the [...] banana, whole plantations may die and the soil may not be suitable for planting for many years to come. Life cycle and appearance of Fusarium wilt Fusarium

Bacterial wilt, brown rot

well in water and in many different soil types and on alternative hosts like weeds. It invades the plants through wounds or stomata and then spreads into [...] pathogenic bacterium. It is a soil-borne disease and colonises the xylem, causing bacterial wilt and brown rot in a very wide range of potential host plants [...] potato, field symptoms of Ralstonia solanacearum are wilting and yellowing of leaves and stunted plants. Inside, vascular browning is common with bacterial

Downy mildew of Cucurbits

stomata. Life cycle and appearance of Downy mildew Pathogens causing downy mildew are not fungi but Oomycetes and related to Pythium and Phytophthora. They [...] during propagation and maintaining a warm and dry climate in greenhouses. Use hygiene measures. Start clean, remove crop residues and prevent splashing [...] pumpkin, watermelon and squash. Damage symptoms Downy mildew pathogens infect mostly the leaves but occasionally also stems and fruits. They cause lesions