• Onion

  common onion, is a vegetable. This particular species is the most extensively produced species of the genus of Allium . The onion plant is usually a biennial [...] biennial or perennial plan. When cultivated however, the plant is mostly handled as an annual and harvested at the end of its first production season. Onions [...] therefore cultivated and used for cooking all around the world. Their flesh is pungent when chopped, because it contains particular chemical elements that irritate

• Glasshouse potato aphid

  colour. When reproduction is asexual, the young aphids are born as developed nymphs. They immediately start to feed on plant sap and grow rapidly. When reproduction [...] deformations in the growing tip of the plant. Precisely where the plant is pierced is unimportant. The piercing of the lower leaves in the crop can cause deformed [...] abdomen that has pale to dark transverse bands. The body shape is similar to wingless females, but is 2.0-3.0 mm long. The glasshouse potato aphid manifests both

• Black root rot of cucurbits

  severe infection, the vines may wilt at a late stage of the crop, but when water supply is in any way limited during earlier periods of high evaporation, wilting [...] adverse conditions for years in the soil, but little else is known about the life cycle. The fungus is dispersed by water, air and soil particles. How to prevent [...] sterilization to the soil/substrate Fumigation with soil disinfectants is only effective when applied evenly Note: since this fungus can rapidly re-colonize the

• Potato aphid

  stripe is dark green, while in pink specimens it is dark red. This longitudinal stripe is specifically characteristic of the potato aphid and is particularly [...] aphid ( Macrosiphum euphorbiae ) is of North American origin, but is these days distributed throughout the world. It is a highly polyphagous species with [...] colour. When reproduction is asexual, the young aphids are born as developed nymphs. They immediately start to feed on plant sap and grow rapidly. When reproduction

• Pea leaf miner

  dirty white. When the larva hatches from the egg, it begins to eat into the leaf at once, tunnelling down into the mesophyll tissue where damage is caused by [...] South and Middle America and has subsequently spread via plant material. It is now wide-spread across the world. This species can be particularly damaging [...] cause damage to plants both directly and indirectly. The most direct damage is caused by the larvae mining the leaf tissue, leading to desiccation, premature

• Tomato russet mite

  especially at high temperatures when population growth is most rapid and affected leaves dry out quickly. The damage is first seen on the lower part of [...] can also be affected, and when this happens in tomatoes, the skin becomes coarse and turns reddish brown and the fruit itself is sometimes deformed. Considerable [...] plants. Aculops lycopersici was detected for the first time in Australia and is a pest in tomatoes in all areas where they are grown. Other members of the

• Phytophthora blight

  infection is either by germinating sporangia or by zoospores produced in the sporangia. For germination on above-ground plant parts, leaf wetness is required [...] This explains why the disease spreads more rapidly when the water content of the soil or substrate is higher than normal or optimal for crop growth. How [...] General Late blight (Phytophthora infestans f.sp. infestans) is also known as Phytophthora blight, tomato blight, early / late blight tomato, potato blight

• Wheat bunt

  tritici and Tilletia laevis only differ in one gene and easily hybridize. There is debate whether they should indeed be considered separate species, since they [...] some or on all spikelets, showing the bunt (smut spore) they contain, which is larger than a normal kernel. The bunt balls are grey-brown. They rupture at [...] The fungi grow between the plant cells and eventually inside the kernels. When that happens, the fungal mycelium turns into teliospores and the whole kernel

• Dwarf bunt

  General Tilletia controversa is a plant pathogen. It is a fungus known to cause the smut disease TCK smut in soft white and hard red winter wheats, as [...] some or on all spikelets, showing the bunt (smut spore) they contain, which is larger than a normal kernel. The bunt balls are grey-brown. They rupture at [...] suitable host for as long as ten years. Seed-borne transmission does occur, but is less important from an epidemiological point of view. The teliospores germinate

• Early blight

  90% or when the leaves are wet. Small differences in optimum temperature occur between species, but in general the risk of Alternaria infection is larger [...] General The only known stage in all Alternaria species is the asexual stage. Conidia and mycelium overwinter in the soil and on crop residues and cause [...] rapidly as two to three days later and sporulation within five days. Infection is both direct and through wounds and stomata. Spores are dispersed by wind and