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.
Rosa L. · Rose
Poulsen Roser Aps (DK)
Hordeum vulgare L. · Barley
J.ADAM
Hordeum vulgare L. · Barley
WIERSUM PLANTBREEDING B.V.
Lolium multiflorum Lam. ssp. italicum (A. Br.) Volkart · Italian ryegrass
D.SAATVEREDELUNG LIPPSTAD
Vitis vinifera L. · Common grape vine
Triticum aestivum L. subsp. aestivum · Bread wheat
Probstdorfer Saatzucht Ges.m.b.H & Co KG
Pisum sativum L. · Pea
Van Waveren Pflanzenzucht (DE)
Triticum aestivum L. · Bread wheat
SECOBRA RECHERCHES S.A.S
Triticum aestivum L. · Bread wheat
Strube Saatzucht KG Söllingen
Beta vulgaris Sugar Beet Group · Sugar beet
Florimond Desprez
Rosa L. · Rose
W. Kordes Sohne Rosenschulen GmbH & Co KG| DE
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Triticum aestivum L. · Bread wheat
Deutsche Saatveredelung AG - DSV (DE)
Humulus lupulus L. · Common hop
Franz Gmelch / Herbert Ehrmaier / Dr. Johann Maier in Bayerische Landesanstalt für Bodenkultur und Pflanzenbau,Abschnitt Hopfen
Triticum aestivum L. · Bread wheat
W. von Borries-Eckendorf GmbH & Co.KG
Beta vulgaris L. · Beet
SESVanderhave NV
Hordeum vulgare L. · Barley
Berthold Bauer (DE)
Triticum aestivum L. · Bread wheat
Saatzucht Donau Ges.m.b.H.& Co KG
Vitis vinifera L. · Common grape vine
Land Baden-Württemberg, vertreten durch Staatliche Lehr- und Versuchs- anstalt für Wein- und Obstbau
Rosa L. · Rose
Pepinieres et Roseraies Georges Delbard| FR
Hordeum vulgare L. · Barley
JOSEF BREUN
Malus domestica (Suckow) Borkh. · Apple
Gospodarstwo Szkółkarskie Andrzej i Szymon Nowakowscy
Beta vulgaris Sugar Beet Group · Sugar beet
KUHN
Triticum aestivum L. subsp. aestivum · Bread wheat
Secobra Saatzucht