Diseases
Erysiphales
Powdery mildew is a fungal disease manifesting as a white web-like coating on plant organs, leading to tissue necrosis, fruit deformation, and significant crop losses.
Mentioned in descriptions 33 570 varieties reference book.
Powdery mildew is caused by ectoparasitic fungi of the order Erysiphales, which develop primarily on the surface of leaves, shoots, and fruits. The initial white web-like coating eventually densifies into "powdery" cushions, upon which fungal fruiting bodies may form as dark spots. As a result of the infection, tissues turn yellow and become necrotic, fruits may crack, and leaves drop prematurely.
The intensity of disease development depends on a complex of factors: high relative humidity, moderate temperatures, the presence of dense canopy, and excessive nitrogen nutrition. Risks increase with alternating dry and wet weather. The harmfulness of the disease is expressed in a reduction of the leaf assimilation area, deterioration of crop quality, and a decrease in the general winter hardiness of crops.
Assessment of variety resistance is conducted under field conditions at various stages of vegetation, most often during the full heading phase. To classify the degree of infection, scoring systems or intensity scales in percentages are used, where varieties with up to 10% infection are considered highly resistant (R), 11 to 40% as moderately resistant (M), and more than 41% as susceptible (S). Variety resistance is ensured by genetic mechanisms that prevent colonization by the pathogen or limit the development of its mycelium.
Selection based on the description text, not official resistance ratings: such data is not available in registers. Mention indicates that the trait is discussed in the variety's sources; see the variety's profile for details on what is specifically stated.
Cucumis sativus L. · Cucumber
Nunhems B.V.
Avena sativa L. · Oat
Plant Breeding International Cambridge Ltd (GB)
Malus domestica (Suckow) Borkh. · Apple
Ústav experimentální botaniky AV ČR, v.v.i. (CZ)
Daucus carota L. · Carrot
Ger Beemsterboer
Pisum sativum L. · Pea
Sharpes International Seeds
Hordeum vulgare L. · Barley
Probstdorfer Saatzucht Ges.m.b.H & Co KG
Triticum aestivum L. · Bread wheat
Institute of field and vegetable crops, Novi Sad, Serbia
Cucumis sativus L. · Cucumber
ZKI, H
Rosa L. · Rose
Meilland, Alain A.|Antibes, France
Helianthus annuus L. · Sunflower
Saaten Union Romania, RO
Cucurbita pepo L. · Field pumpkin
MoravoSeed, CZ
Cucurbita pepo L. · Field pumpkin
Vilmorin, F
Triticum aestivum L. · Bread wheat
Blackman Agriculture Ltd
Cucumis sativus L. · Cucumber
RIJK ZWAAN ZAADTEELT EN ZAADHANDEL B.V.
Malus domestica (Suckow) Borkh. · Apple
Institute of Experimental Botany AS CR, Czech Republic
Cucurbita pepo L. · Field pumpkin
Ralf Kuijpers
Rosa L. · Rose
MEILLAND ALAIN ANTOINE
Hordeum vulgare L. · Barley
LIMAGRAIN
Cucumis sativus L. · Cucumber
Seminis Vegetable Seeds
Hordeum vulgare L. · Barley
Sejet Planteforaedling I,S
Triticum aestivum L. · Bread wheat
Instytut Hodowli i Aklimatyzacji Roslin Panstwowy Instytut Badawczy
Triticum aestivum L. · Bread wheat
KWS Momont Recherche Sarl
Hordeum vulgare L. · Barley
Limagrain Europe S.A.S
Hordeum vulgare L. · Barley
Limagrain Europe S.A.S