• Blight of pepper

  brown-black lesions occur on the larger roots. Plants wilt and the crown leaves drop off. Life cycle and appearance of Blight of pepper Phytophthora species [...] pathogen grows into the stem and on the plant surface and new sporangiophores (structures containing sporangia, a type of spores) with sporangia are formed [...] and fruit rot of peppers and other important commercial crops. Damage symptoms Phytophthora causes root rot, seedling damping off and rot of stems, bulbs

• Root rot of carrot

  leaf spots Life cycle and appearance of Root rot of carrots The fungus of R. carotae has delicate, simple morphological features hence is not easy to place [...] only host plant of the fungus. How to prevent root rot of carrot Studies have shown that 3several key factors influencing the occurrence of blemishes and [...] Additionally a strong foliage and uniform stand allow better functioning of mechanical harvesters, leading to less mechanical damage of the carrots.

• Loose smut of barley

  emergence. The first sign of infection is the appearance of a smutted ear. Instead of normal tissue, the ear contains a mass of olive-brown smut spores. [...] hordei affects barley and can destroy a large proportion of the crop. It is also known as barley smut, or loose smut of barley. Damage symptoms Infection by [...] cycle and appearance of Loose smut of barley The seeds are infected during flowering and the infected seeds are the primary source of inoculum in the next

• Loose smut of wheat

  emergence. The first sign of infection is the appearance of a smutted ear. Instead of normal tissue, the ear contains a mass of olive-brown smut spores. [...] cycle and appearance of Loose smut of wheat The seeds are infected during flowering and the infected seeds are the primary source of inoculum in the next [...] that are formed on systemically infected seeds then infect neighbouring new seeds. They germinate within a day and infect the inner tissues of the newly infected

• Downy mildew of Cucurbits

  They cause lesions on the upper leaf surface, bordered by the veins, which are first yellow and then turn brown. On the underside of the leave fluffy growth [...] leaves and after a while new spore-bearing structures are protruding from the stomata. Because there are more stomata on the underside of the leaf, this [...] General Pseudoperonospora cubensis is a plant pathogen causing downy mildew on cucurbit crops like cucumber, cantaloupe, pumpkin, watermelon and squash

• Black rot of carrots

  appearance of Black rot of carrots Black rot of carrots ( Alternaria radicina ) is a seed-transferred carrot disease. The seeds are the main source of primary [...] in the soil and on crop residues and cause primary infection of the leaves. Survival can be several years, in the case of black rot of carrots ( Alternaria [...] Damage symptoms Black rot of carrots ( Alternaria radicina ) causes death of seedlings and dark brown lesions with a yellow halo on leaves, growing into crown

• Black leg of seedlings

  and very little of the root system survives. On the border between air and soil or substrate the plant turns brown. A typical symptom of a Pythium infection [...] stripping of the skin from the root cortex with a finger nail. Life cycle and appearance of Black leg of seedlings Pythium belongs to the Oomycetes, a separate [...] conditions, especially dehydration. Germination of the oospores is stimulated by exudates from roots of a susceptible host nearby. The oospores germinate and form

• Bacterial canker of tomato

  structures Use a crop rotation in field crops of at least two years and alternate with a non-host crop Apply deep-ploughing to stimulate the decay of crop residues [...] lose their entire crop of the affected field and potatoes from other fields on the farm, are labelled as ‘suspect’ that year. On the infected field no potatoes [...] years. On other fields on the same farm, no seed potatoes can be grown for one year after infection. Damage symptoms Clavibacter causes spots on stems,

• Pierce's disease of grapevine

  lesions occur on the underside of the leaves. These lesions start out in a light-brown colour, turning to dark-brown or necrosis. Fruits of infected trees [...] olive. Damage symptoms Grapevines: Primary infection of leaves results in leaf scorch. Part of a green leaf suddenly dies and turns brown with adjacent [...] thinner, but the trees don’t die of the disease. Olives: Scorch symptoms and desiccation of twigs and small branches occur on infected leaves. This usually

• Black root rot of cucurbits

  spots with a dark demarcation line on cucumber roots. The lesions are slightly sunken and are mostly formed around the point of attachment of lateral roots [...] in this stage may kill the plants. In case of a less severe infection, the vines may wilt at a late stage of the crop, but when water supply is in any way [...] disease is usually restricted to a few of the roots but in severe cases all roots may be infected. At the final stage of the disease, only vascular tissue