• Cercospora leaf spot

  reduced yield. Stem, petiole and pods are also infected with Cercospora with typical grey centres with dark brown borders. [...] plants and plant debris are primary source of infection. Secondary spread is through air borne conidia. High humidity favours the spread of the disease [...] symptoms. Symptoms Leaf spots are characteristically greyish brown, circular with small to large grey centres and dark brown margins. The spots may enlarge

• Root rot of carrot

  As far as is known, Daucus carota (carrot) is the only host plant of the fungus. How to prevent root rot of carrot Studies have shown that 3several key [...] symptoms Rhexocercosporidium carotae is a slow-growing fungus that can infect both roots and foliage. The infection starts with small black spots over the entire [...] soil and the air. The fungus develops at temperatures ranging from -3°C to 25°C, with an optimum around 18°C. Lesions are dark brown to black, moist, mostly

• Brown root rot, corky root rot

  corky areas often occur as horizontal bands on the roots with lengthwise cracks. No discoloration is present in the xylem tissues which distinguishes it from [...] General Pyrenochaeta lycopersici is a fungal plant pathogen, infecting tomatoes and aubergine. It causes brown root rot and corky root rot. Damage symptoms [...] temperatures above 20 °C. The fungus produces pycnidia containing conidiophores with conidia and microsclerotia. Spread happens through dispersal of soil particles

• Fusarium wilt

  General Fusarium is a group of soil-borne fungi with many different species. Fusarium is widespread and can infect a range of host crops. Many species [...] mycelium cells) or mycelium. Survival is also possible on seed, greenhouse structures, tools and machinery. Primary infection is either seed-borne or takes place [...] fruit rot, head blight in cereals and post-harvest decay. Fusarium oxysporum is the species causing vascular wilt. First the leaves turn yellow and wilt,

• Southern blight

  southern blight is a disease caused by the fungus Athelia (Sclerotium) rolfsii . It is an important plant pathogen that inhabits the soil, and is responsible [...] fungus Athelia (Sclerotium) rolfsii is characterized by the production of vigorous mycelium. When the mycelium is young it is white; later it darkens. There [...] cotyledons, and roots. The main damage caused by damping-off is reduction of the stand, meaning it is very often necessary to replant, which increases the crop's

• Potato aphid

  m euphorbiae ) is of North American origin, but is these days distributed throughout the world. It is a highly polyphagous species with a preference for [...] aphids are 1.7 - 3.6 mm long, elongated, with a dark longitudinal stripe running along the dorsal surface. In green individuals, this 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 visible in the

• Cotton bollworm

  reddish-brown with dark spots. In later instars the head is mottled, and the body is marked with three prominent longitudinal dark bands with numerous lighter [...] They are almost spherical with a flattened base and a diameter of about 0.5 mm. They are at first a shiny yellowish white, with their colour changing to [...] aggressive and cannibalistic. Pupation occurs in the soil, with pupae of 14 to 18 mm long, with a brown, smooth body surface. Adult female cotton bollworms

• Diamond back moth

  dark, sometimes suffused with ochre or mixed with whitish scales. The lower one-third of the forewing is ochreous-white, with a nearly white upper edge [...] xylostella) is suggested to have its origin in Europe, South Africa or East Asia, but is now present wherever its cruciferous hosts exist and it is considered [...] larval instars. The body tapers at both ends and is green, sometimes suffused with pale yellow, with a few short hairs and small white patches. The larva

• Rose aphid

  rosae , is a serious and often abundant pest of roses. It is virtually cosmopolitan and widely spread in Europe. Damage symptoms Infestations with rose aphids [...] contaminated with sticky honeydew on which black sooty moulds develop. Life cycle and appearance of Rose aphid Aphids have a complex life cycle, with both winged [...] is, with unfertilized viviparous females continuing to produce new generations of females. Aphids moult four times before reaching adulthood. With each

• Glasshouse potato aphid

  Precisely where the plant is pierced is unimportant. The piercing of the lower leaves in the crop can cause deformed growth above with lumpy leaves and curled [...] have a complex life cycle, with both winged and wingless forms of adults and a great variety in colour. When reproduction is asexual, the young aphids are [...] When reproduction is sexual, the aphids lay eggs that overwinter. In greenhouses reproduction also takes place by parthenogenesis, with unfertilized viviparous