• Cottony soft rot

  base and the roots, whereas the ascospores infect the above-ground plant parts. In greenhouses, usually only mycelium is produced by the germinating sclerotia [...] sclerotia. The fungus grows quite rapidly inside the plant and kills the host cells. On the infected plant tissue white, fluffy mycelium occurs with new [...] Damage symptoms The first symptoms of a cottony soft root ( Sclerotinia sclerotiorum ) infection are water-soaked lesions at the stem base. The plant above

• Phytophthora blight

  fungal 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 [...] from the root to the foot, but direct infection of the foot also occurs. Exudates leaking from growing root tips promote germination and attract the zoospores [...] wind and rain causes the pathogen to be returned to the soil from infected plants. Dispersal in the soil happens via water, since the zoospores can readily

• Bacterial wilt, brown rot

  s roots on the stem. The vascular stem tissue is coloured brown and when the stem is cut, bacterial slime oozes from the wound. This is the way to distinguish [...] signs of wilting during the day which may disappear in the early stages of infection. Under conditions favourable for the bacteria, the whole plant will wilt [...] common with bacterial slime oozing from the cut. When the bacteria transfers to young plants through infected tubers, the wilting and collapse of plants happens

• Fusarium wilt

  oxysporum is the only Fusarium that actually grows inside the vessel system of the host plant and spreads upwards inside the plants. The other species [...] Fusarium oxysporum is the species causing vascular wilt. First the leaves turn yellow and wilt, mostly on one side of the plant. Finally, the whole plant wilts [...] brown discolouration of the xylem vessels which can be seen when the stems are cut. In banana, whole plantations may die and the soil may not be suitable

• Black rot of carrots

  spores surviving in the soil are the main source of infection. Especially wheat and barley reduce the number of surviving conidia in the soil. Use resistant [...] 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 [...] seed-transferred carrot disease. The seeds are the main source of primary infection and this may lead to death of seedlings. From the primary infection of leaves

• Early blight

  occur at the side of the stem. Life cycle and appearance of Early blight From the primary infection of leaves, Alternaria solani can spread to the flowers [...] spores surviving in the soil are the main source of infection. Especially wheat and barley reduce the number of surviving conidia in the soil. Use resistant [...] 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

• Corn rootworm

  year. The pest overwinters in the soil in the egg stage. Egg hatching start in the middle of May and continues until the begin of July, with the presence [...] feeding, although it is the former that causes the most extensive damage. The larvae feed on the rootlets and dig tunnels in the larger roots. This leads [...] black stripes on the wing covers. They emerge throughout the summer period with a peak between the end of June and the middle of July. The adults may mate

• Tobacco whitefly

  wings of the adult are already clearly visible. These pupae are found on the oldest leaves. The adult emerges from the pupa via a T-shaped fissure. The adult [...] adult. The larvae are found on the underside of young leaves and have an oval shape. The first instar larvae (crawlers) are mobile, whereas the rest of [...] of the larvae stadia remain flattened on the leaf. The fourth larva stadium develops into a yellow, almost circular so called pupa, in which the red eyes

• Beet armyworm

  es for the growth of the crop. With a substantial population of caterpillars, the damage can spread to the stems, and in the worst cases to the fruit. [...] even black. The colour and pattern of the caterpillars is highly variable and depends partly on the host plant, the stage of development and the climate. [...] plants. In both the greenhouse and the field, it is a major pest of sweet pepper. Damage symptoms Older caterpillars migrate to the top of the plant where

• Southern European marshland pyralid

  caterpillars often stay in the lower strata of the crop, sometimes attacking the stem of the plant as well as the leaves. Late instar larvae burrow into soft [...] tile-like fashion on both the upper and lower surface of leaves close to the veins, or low on the stem or stalk close to the ground. The pinkish red eggs are [...] possibly stem collapse. The holes bored into the stem can facilitate infection by the fungus Botrytis cinerea . In gerbera, the flower buds may also be