• Bacterial canker of tomato

  occurs in the second half of the season. The first symptoms are wilting of the lower leaves and subsequent expansion of the wilt upwards. Cutting the stem at [...] tools. The bacteria infect the new plants by entering through wounds and then growing into the vessels of the plant. Plant growth is inhibited and the plant [...] infection is found, strict measures are taken to eradicate the infection. In tomato, growers must either destroy the infected crop entirely or, if the crop

• Obscure mealybug

  wax, the filaments around the body are longer (20-50% of the body size) and the two tail filaments are always markedly longer than the others. The obscure [...] their name from the fact that the body of the females from the third nymphal instar onwards are covered with a white waxy material in the form of powder, threads [...] active. From the second instar onwards the life cycle of males anf females is completely different. After the second instar, the males form a dark false

• Angular leaf spot

  underside of the leaf. They enlarge to angular spots, often limited by the small veins. The distinctive feature is the way the lesions look when using different [...] leaves or leaves in the soil, but not independantly in the soil. Under humid conditions, bacteria ooze from the lesions on the leaves and form a secondary source [...] visible on the upper side of the leaf as irregular spots which are first reddish brown and then become necrotic. The foliar symptoms are the most important

• Cotton aphid

  as chrysanthemum and kalanchoe. The cotton aphid ( Aphis gossypii ) is distributed throughout the world but prefers the warmer regions. It has been a pest [...] greenhouses since the late 1980’s, particularly affecting cucumber. Damage symptoms The cotton aphid ( Aphis gossypii ) is an important vector for viral diseases [...] including the cucumber mosaic virus. Nymphs and adults extract nutrients from the plant and disturb the balance of growth hormones. As a result, the plant’s

• Loose smut of wheat

  survives inside the seed and when the seed germinates, the mycelium of the fungus grows upwards inside the plant into the growing tip and the seed primordia. It [...] Loose smut of wheat The seeds are infected during flowering and the infected seeds are the primary source of inoculum in the next crop. The fungus survives [...] invisible until head 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

• Root and crown rot of strawberry

  rot reported mainly from Brazil. The genus is quite complex, so the taxonomy may change. Pestalotiopsis clavispora is also called Neopestalotiopsis clavispora [...] strawberry. Plant development is slow, growth is retarded and rooting is poor. Transplants look weak and may die. It is hard to visually distinguish between [...] rot of strawberry Not much is known about the life cycle. The fungus produces ascospores and conidia, but their role in the epidemic has not yet been

• Black bean aphid

  As a result, the plant’s growth is retarded giving rise to deformed leaves or, if the infestation occurs early enough in the season, the death of young [...] betraying their presence in the crop. The black bean aphid is dark olive green to black with black bands across the back. The two cornicles (or siphunculi) [...] General The black bean aphid, Aphis fabae , is widespread in temperate regions, where it is a serious economic pest of beans. It is highly polyphagous

• Diamond back moth

  like those of the males. The back is marked with a broad cream or light brown band along the back, which is sometimes constricted to form one or more l [...] regions. Damage symptoms The caterpillar is a surface feeder. They feed from the lower leaf surface, leaving the wax layer on the upper surface intact, thereby [...] may occur in the florets. Initially, the pupa is pinkish-white to pinkish-yellow and changes to brown before adult emergence. The adult of the diamond back

• Loose smut of barley

  survives inside the seed and when the seed germinates, the mycelium of the fungus grows upwards inside the plant into the growing tip and the seed primordia. It [...] smut of barley The seeds are infected during flowering and the infected seeds are the primary source of inoculum in the next crop. The fungus survives [...] invisible until head 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

• Downy mildew of Cucurbits

  around 15 o C and the closer the temperature is to this, the shorter the leaf wetness period that is required. Inside the plant, the pathogens produce haustoria [...] through the stomata or directly by penetrating the cuticula. For germination free water is required. For most downy mildews, the optimum temperature is around [...] brown. On the underside of the leave fluffy growth appears which is first white and later turns grey-brown. This is actually the sporulation of the pathogens