• Fusarium head blight or scab

  the soil and on crop residues of infected plants as chlamydospores (thick walled mycelium cells) or mycelium. Survival is also possible on seed, greenhouse [...] was infected or by direct infection of the foot by overwintering inoculum. On the infected foot, conidia are produced that further spread the disease. [...] spores are dispersed upwards to the ears by splashing rain drops or wind. On the infected ears, the typical pink spores are produced which may further

• Apple scab

  apple scab include: Olive-green to dark brown velvety spots on leaves Brown or black lesions on developing fruit Cracked, corky, misshapen, or rusted fruit [...] Inspect orchards for: Olive-green or brown lesions on young leaves and developing fruit Brown or black spots on cluster leaves, extension shoots, and developing [...] Venturia inaequalis primarily survives the winter in infected fallen leaves on the orchard floor. Within these leaves, the fungus forms pseudothecia, which

• Phytophthora blight

  growth on the leaves. The centre is grey-brown with a light-green edge. On the stem, elongated brown lesions occur, usually circling the stem. On potato [...] 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

• Angular leaf spot

  symptoms Xanthomonas fragariae initially causes small, water-soaked lesions on the underside of the leaf. They enlarge to angular spots, often limited by [...] translucent. When conditions are humid, a viscous bacterial exudate forms on the underside of the leaf. This exudate changes to a white film when it dries [...] dries. Lesions may merge as they grow and later also become visible on the upper side of the leaf as irregular spots which are first reddish brown and then

• 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

• 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

• Foot rot of cereals

  staining of the lower nodes. Long dark streaks may also appear at the stem base. On older plants, infection can produce a true foot rot, where the stem base becomes [...] bleaching of the ears. The presence of orange/pink spores may also be visible on infected spikelets. As the crop ripens, symptoms become less visible. At harvest [...] the cycle. Microdochium nivale manifests as white to pinkish fungal growth on infected plant tissues, often accompanied by dark lesions and rotting of roots

• 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