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.
Vitis vinifera L. · Common grape vine
Pavlova Iryna Oleksandrivna, Oleinikov Mykola Petrovych, Lykhovs`koi Volodymyr Volodymyrovych, Volynkin Volodymyr Oleksandrovych, Avidzba Anatolii Mkanovych,
Clematis L. · Clematis
Wim Snoeijer
Ribes uva-crispa L. · Gooseberry
Shestopal Halyna Serhiivna, Kopan Volodymyr Pavlovych, Kopan` Kira Mykolaivna,
Cucumis sativus L. · Cucumber
IBEROSEEDS COMPAÑIA IBERICA DE SEMILLAS, S.L.
Cucumis melo L. · Melon
Kornelius Reinink
Hordeum vulgare L. · Barley
Mareniuk Oleksandr Borysovych, Suslova Tetiana Vasylivna, Korniichuk Oleksii Oleksandrovych, Honchar Tetiana Mykolaivna, Betsenko Liudmyla Bronislavivna, Koniichuk Oleksandr Vasyl`ovych, Doroschuk Vasyl` Oleksiiovych,
Cucumis sativus L. · Cucumber
Кees Reinink
Cucumis sativus L. · Cucumber
Yost van den Eiden
Lactuca sativa L. · Lettuce
RIJK ZWAAN Z.Z. B.V.
Veronica spicata L. · Spiked speedwell
A T Yates & Son
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Fresh Forward Holding B.V.
Vitis L. · Grapevine
INCONNU (FR)
Rosa L. · Rose
Marchenrose Co. Ltd.
Cucumis melo L. · Melon
Enza Zaden Beheer B.V.
Cucumis sativus L. · Cucumber
SEMILLAS FITO, S.A.
Lactuca sativa L. var. capitata L. · Head lettuce
Kees Reinink
Chrysanthemum L. · Chrysanthemum
PETER WAIN
Ribes rubrum L. · Redcurrant
Solanum lycopersicum L. · Tomato
Kees Reinink
Salvia L. · Sage
Hans A. Hansen
Cucumis melo L. · Melon
RIJK ZWAAN Z.Z. B.V.
Coreopsis L. · Tickseed
Kong Young Park
Ribes uva-crispa L. · Gooseberry
Shestopal Halyna Serhiivna, Kopan Volodymyr Pavlovych, Kopan` Kira Mykolaivna,
Begonia x hiemalis Fotsch · Elatior Begonia
Begonia Breeders Association B.V.