Phytophthora blight

enable them to move through water. Infection is usually from the root to the foot, but direct infection of the foot also occurs. Exudates leaking from growing [...] required. Dispersal is by wind and rain causes the pathogen to be returned to the soil from infected plants. Dispersal in the soil happens via water, since [...] (thick-walled mycelium cells which are resistant to desiccation) or mycelium. Zoospores are formed from the overwintering structures which infect the host

Black leg of seedlings

stripping of the skin from the root cortex with a finger nail. Life cycle and appearance of Black leg of seedlings Pythium belongs to the Oomycetes, a separate [...] which are resistant to unfavourable conditions, especially dehydration. Germination of the oospores is stimulated by exudates from roots of a susceptible [...] so-called sporangia from which subsequently zoospores are produced. Zoospores are spores with flagellae, which enable the spores to move through water.

Bacterial canker of tomato

strong efforts are used to prevent the bacterium from entering. When the occasional infection is found, strict measures are taken to eradicate the infection [...] disinfection has been proven to the authorities. Potato growers lose their entire crop of the affected field and potatoes from other fields on the farm, are [...] lavibacter infection, but other than that the disease is difficult to distinguish from wilting caused by other pathogens. On potato tubers, first discolouration

Crazy roots, hairy roots, crown gall

have been isolated from crazy roots. This disease seems to be caused by a change in the hormonal system of the plant resulting from the Rhizobium infection [...] Adjust the work order in greenhouses to fit with the hygiene protocol Disinfect the nutrient solution in order to prevent biofilm growth inside the irrigation [...] Additionally, pathogenic Agrobacterium s pecies have recently been assigned to the genus Rhizobium . These pathogenic bacteria were formerly known as Ag

Plant health

Tarnished plant bug

plant bug) is native to North America, and it is especially common across the eastern half of the continent, from northern Canada to southern Mexico. It [...] up to 6.5 mm in length and are variable in colour; generally they are brown with yellow, orange or red accents, but their colouring can range from pale [...] species, known to feed on almost all commercial crops. Lygus lineolaris boasts at least 385 different host species, the majority of which belong to the plant

Cut flowers

originates from Central and South America. It is a bulb plant from the large family of the Amaryllidaceae, the narcissus family. The Hippeastrum comes from America [...] America, from northern Argentina to Mexico and the Caribbean. Is grown from a bulb as a cut flower or sold as a pot plant. Freesia : The freesia is a herbaceous [...] substrate differ greatly. Important types are: Rose: The rose belongs to the genus Rosa from the Rosaceae family. The flowers of the plant are also called rose

Powdery mildew

and makes it harder for the fungi to enter the leaves To reduce chances of powdery mildew in greenhouses, it is advised to first ventilate by only opening [...] structures are produced, the haustoria, from which the fungus penetrates the plant cell and takes up nutrients from the epidermal layer of plant cells. Most [...] appear on the upper side of the leaves. Many sweet pepper cultivars react to powdery mildew infection by dropping leaves that are not infected yet. It

Black rot of carrots

infection and this may lead to death of seedlings. From the primary infection of leaves, this type of carrot disease can spread to the flowers (especially [...] post-harvest storage. Sporulation of Alternaria occurs at temperatures from 2-4 °C up to 28-30 °C (optimum temperatures lie between 15 and 28 °C) and at a relative [...] A. brassicae and A. brassicicola : adjust the sowing date to avoid conditions conducive to infection. In greenhouses: avoid high RH. Prevent plant diseases

Spotted Wing Drosophila

oviposition, the respiration tubes extend from the fruit but are difficult to see. Larval feeding in the fruit leads to fruit tissue collapse. Even if the fruits [...] exposes fruits to secondary pathogens (e.g. bacteria, fungi and yeasts). Finally, deterioration of fruit can increase its susceptibility to attack by other [...] distinguished from males of other Drosophila species or SWD females by a large dark spot on each wing, where their common name is derived from. Females have