Root rot of carrot

carrots are a major problem and can lead to significant postharvest losses Several different fungal pathogens cause similar symptoms, which are collectively [...] collectively known as black spot diseases. When carrots are stored during winter, diseases on the carrot roots can continue to develop during storage. Alternaria [...] and eventually cover the entire surface of the carrot. The affected areas are firm, shallow, and clearly visible. Under certain conditions, an olive-green

Crazy roots, hairy roots, crown gall

takes place via wounds. After infection, galls are formed which break open, releasing many bacteria. These are dispersed by rain and wind and by humans and [...] General Rhizobium bacteria are soil bacteria that fix nitrogen after becoming established inside root nodules of legumes. Additionally, pathogenic Agr [...] root growth. All four species cause the growth of galls on the stems, which are first white and later turn brown. Only Rhizobium radiobacter causes galls

Cyclamen mite

adult mite. They are oval in form, smooth, transparent and twice as long as they are wide. Both ends are equally rounded. The larvae are opaque white and [...] The males are smaller than the females and their hind legs are modified and used to transport pharate females. Eggs of the cyclamen mite are about half [...] parts. The mites are mostly found within the flower buds, growing tips and young folded leaves, where the humidity is highest and they are protected from

Grey mould

mould’s ( Botryotinia fuckeliana / Botrytis cinerea ) most common symptoms are grey-brown lesions. The lesions occur on leaves, stems, fruits and flowers [...] content of the plant cells as nutrients. On the infected area, new spores are formed within a few days. Under circumstances unfavourable for germination [...] surface and still germinate when the RH increases, for example when cut flowers are harvested and put into cold storage. Wounds can also provide the fungus with

Bacterial canker of tomato

means that strong efforts are used to prevent the bacterium from entering. When the occasional infection is found, strict measures are taken to eradicate the [...] 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 or other [...] usually only occurs in the second half of the season. The first symptoms are wilting of the lower leaves and subsequent expansion of the wilt upwards.

Sciarid flies

. Lycoriella species are mainly found in commercial mushroom cultivation where they can cause enormous damage. Sciarid flies are usually found in damp [...] little, plant death is generally local. Young plants that are kept humid and well-watered are particularly at risk. Life cycle and appearance of Sciarid [...] hardly feed at all during their short life. The males are usually smaller than the females. They are not fast fliers, and prefer damp areas in dark places

Shallot aphid

stunted when growth starts in spring. Petioles are shortened and leaves curled and twisted. Blossom trusses are also affected, fruits remain small and yield [...] Wingless females of the shallot aphid are 1.1-2.2 mm long and shiny brownish green to dirty yellow. Their legs and antennae are pale, apart from the ends of the [...] build up even in winter and early spring when temperatures are still low. Winged forms are produced and migrate to other crops until June.

Cutworms

circular position. Pupa are brown to dark brown and 17-25 mm long. Females are capable of laying several hundred eggs. There are six to seven larval stages [...] General Cutworms ( Agrotis spp.) are occurring worldwide. Important species are for instance the black cutworm Agrotis ipsilon and the turnip moth Agrotis [...] thorax is covered with close-lying hairs. The eggs are white at first but rapidly turn darker. They are laid separately or in batches on the ground, or on

Click beetles

appearance of Click beetles Adult Agriotis sp. are 6-10 mm long and yellowish brown to black. The eggs are laid in May or June in groups in the soil. They [...] start to feed on roots. The larvae (‘wireworms’) are long, thin, cylindrical and though skinned. They are up to 25 mm long and usually shiny yellowish brown [...] General Click beetles are elongate beetles with a hard exoskeleton, with the head deeply retracted into the thorax. When disturbed they lie on their back

Chafers

The chafers are beetles of the Scarabaeidae family. The larvae of both species live in the soil and feed on the roots of many plants. They are a serious [...] lay their eggs. Eggs are shiny and white. The eggs hatch after about four weeks and the larvae start to feed on roots. The larvae are white-coloured, C-shaped [...] serious pest that can cause substantial damage. The adults are not harmful. Damage symptoms Larval feeding on the roots can lead to yellowing and wilting of plants