• Pierce's disease of grapevine

  desiccation of twigs and small branches occur on infected leaves. This usually starts in the upper part of the canopy on a few branches and then extends to the [...] young infected trees show dwarfing. Leaves and flowers appear early and remain on the plant longer, but fewer and smaller fruits are produced. In plums, the [...] certain branches. When the leaves mature, slightly raised gummy lesions occur on the underside of the leaves. These lesions start out in a light-brown colour

• Leaf stripe

  yield losses. Damage symptoms Symptoms first occur on the first, second and third leaf and subsequently on other leaves. Yellow stripes are formed at the base [...] The fungus spreads from the seed into the seedling. Conidia are produced on the infected leaves when humidity is high and wind-dispersed to neighbouring

• Bacterial wilt, brown rot

  the plants may show signs of stunting and produce many adventitious roots on the stem. The vascular stem tissue is coloured brown and when the stem is [...] temperate regions. It survives well in water and in many different soil types and on alternative hosts like weeds. It invades the plants through wounds or stomata [...] cutting knives and tools Control root rot nematodes as the wounds they make on roots help the bacteria to infect the crop Do not use cut potatoes for propagation

• Brown root rot, corky root rot

  lesions. On older roots, the outer layers become swollen and corky and gradually break off. The corky areas often occur as horizontal bands on the roots [...] Disinfect nutrient solutions General: Choose resistant cultivars or graft on resistant rootstock Avoid frequent irrigation. Remove and destroy affected

• Crazy roots, hairy roots, crown gall

  galls on the stems, which are first white and later turn brown. Only Rhizobium radiobacter causes galls and tumours on underground plant parts and on the

• Blight of pepper

  crown rot in potted plants. The small roots die and brown-black lesions occur on the larger roots. Plants wilt and the crown leaves drop off. Life cycle and [...] germination and attract the zoospores. The pathogen grows into the stem and on the plant surface and new sporangiophores (structures containing sporangia [...] germinating sporangia or by zoospores produced in the sporangia. For germination on above-ground plant parts, leaf wetness is required. Dispersal is by wind and

• Wheat bunt

  remain green longer than healthy heads. The glumes are opened either on some or on all spikelets, showing the bunt (smut spore) they contain, which is larger [...] Tilletia tritici and Tilletia laevis survive as teliospores in the soil or on seed. These teliospores germinate in response to moisture and form basidiospores

• Dwarf bunt

  remain green longer than healthy heads. The glumes are opened either on some or on all spikelets, showing the bunt (smut spore) they contain, which is larger [...] of Dwarf bunt Tilletia controversa survives as teliospores in the soil or on seed. The soil-borne teliospores are the main source of primary infection

• Black leg of seedlings

  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. A typical [...] where the side roots are formed or through other similarly damaged spots. On the infected plant, new sporangia with zoospores are formed, that allow the [...] plants. How to prevent Black leg of seedlings Use resistant cultivars or graft on tolerant cultivars Use clean planting material Ensure regular growth Avoid

• Damping-off

  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. A typical [...] where the side roots are formed or through other similarly damaged spots. On the infected plant, new sporangia with zoospores are formed, that allow the [...] not harm plants. How to prevent Damping-off Use resistant cultivars or graft on tolerant cultivars Use clean planting material Ensure regular growth Avoid