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
Dr. Norbert Becker im Staatl. Weinbauinstitut
Cucumis sativus L. · Cucumber
RIJK ZWAAN Z.Z. B.V.
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Cucumis melo L. · Melon
Louis Poloni (FR)
Cucumis melo L. · Melon
Angeles Maria
Vitis vinifera L. · Common grape vine
Chizmaziia Dorab Iozef
Vitis vinifera L. · Common grape vine
Zdravko Nakov, Vasil Valchev, Miroslav Ivanov, Vanyo Haygarov
Vitis vinifera L. · Common grape vine
Dr. Norbert Becker im Staatl. Weinbauinstitut
Hordeum vulgare L. · Barley
Centre de Recherches Agronomiques de Gembloux (BE)
x Triticosecale Wittm. ex A. Camus · Triticale
AGRI OBTENTIONS / INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE (I.N.R.A.)
Citrullus lanatus (Thunb.) Matsum. & Nakai · Watermelon
INTERSEMILLAS, S.A.
Ribes rubrum L. · Redcurrant
Sherenhovyi Vitalii Petrovych, Silenko Volodymyr Oleksandrovych, Sherenhovyi Petro Zakharovych,
Capsicum annuum L. · Bell pepper
RAMIRO ARNEDO, S.A.
Begonia x hiemalis Fotsch · Elatior Begonia
NILSSON CHRISTER| Christer und Peter Nilsson
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Vitis L. · Grapevine
INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE, FR
Vitis vinifera L. · Common grape vine
Dr. Norbert Becker im Staatl. Weinbauinstitut
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Vitis vinifera L. subsp. vinifera · Wine grape
Yordan K. Ivanov, Vasil Y. Valchev, Kunyu D. Stoev, Zdravko D. Zankov
Hordeum vulgare L. · Barley
HEIDENREICH EGER| Eberhard Heidenreich und Erhardt Eger (als Gesellschaft
Rosa L. · Rose
Jean Louis FONCELLE (FR)
Cucumis melo L. · Melon
SEMILLAS FITO, S.A.
Cucumis sativus L. · Cucumber
Krylov Oleh Mykolaiovych, Borysov Oleksandr Volodymyrovych,