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
IBEROSEEDS COMPAÑIA IBERICA DE SEMILLAS, S.L.
Cucurbita pepo L. · Field pumpkin
Julien Mazet
Pisum sativum L. · Pea
Vovk Zhanna Mykolaivna
Triticum turgidum L. subsp. dicoccum (Schrank ex Schübl.) Thell. · Emmer
Národní centrum zemědělského a potravinářského výzkumu, v. v. i. (CZ)
Begonia L. · Begonia
Hoefnagels B.V.
Rosa L. · Rose
Tovarystvo z obmezhenoiu vidpovidalnistiu "ShYPShYNA UKRAINY",Tovarystvo z obmezhenoiu vidpovidalnistiu «PLANTEKS»,
Malus domestica (Suckow) Borkh. · Apple
Information not available - Contact NL authorities
Triticum aestivum L. · Bread wheat
ROTHWELL P.B.
Triticum aestivum L. · Bread wheat
RAGT CZECH S.R.O.
Vitis vinifera L. · Common grape vine
Zdravko Zankov, Ivan Todorov, Kunyu Stoev
Triticum aestivum L. · Bread wheat
Lundin, Per/Svensson, Gunnar
Triticum aestivum L. · Bread wheat
RAGT 2n
Cucumis sativus L. · Cucumber
Havrysh Serhii Fedorovych, Dubinin Serhii Volodymyrovych,
Vitis vinifera L. · Common grape vine
MINCHO GUENCHEV KONDAREV
Chrysanthemum indicum L. · Indian chrysanthemum
W. John LAYNG (US)
Vitis vinifera L. · Common grape vine
Ovchynnikov Hryhorii Petrovych, Tarakhtii Liudmyla Ivanivna, Abliazova Aia Pavlivna, Tulaieva Maia Ivanivna, Dokuchaieva IEvheniia Mykolaivna,
Fragaria L. · Strawberry
Philippe Chartier
Vitis vinifera L. · Common grape vine
Prof. Dr. H. Becker
Vitis L. · Grapevine
R.Gilg et Succ. SA (FR)
Fragaria L. · Strawberry
Kopan Volodymyr Pavlovych, Kopan` Kira Mykolaivna,
Solanum lycopersicum L. · Tomato
Syngenta Crop Protection AG
Rosa L. · Rose
BAUM KARL| Karl Baum
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Cucumis melo L. · Melon
Ernest Garcia