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.
Brassica oleracea L. (Broccoli Group) · Broccoli
Ger Beemsterboer
Beta vulgaris Sugar Beet Group · Sugar beet
Khart Rodzher Evelin
Cucurbita pepo L. · Field pumpkin
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Hordeum vulgare L. · Barley
DR ERNST REHSE
Cucumis sativus L. · Cucumber
Sakata Vegetables Europe SAS (FR)
Hordeum vulgare L. · Barley
Serasem, FR
Cucumis sativus L. · Cucumber
Lim Sang Hwa
Capsicum annuum L. · Bell pepper
Nunhems B.V.
Hordeum vulgare L. · Barley
WUSTRACK| Dr. Hans-Joachim Wustrack
Triticum aestivum L. · Bread wheat
Moskalets` Tetiana Zakharivna, Moskalets` Valentyn Vitaliiovych, Moskalets` Vitalii Ivanovych, Pysarenko Pavlo Viktorovych, Tyschenko Volodymyr Mykolaiovych,
Vitis vinifera L. · Common grape vine
Tarakhtii Liudmyla Ivanivna, Meleshko Larysa Fedorivna, Yarmak IEvheniia Dmytrivna, Storozhuk Kateryna Moiseivna, Dylyk Antonina Petrivna, Dokuchaieva IEvheniia Mykolaivna, Chebanenko IEvheniia Pavlivna,
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Triticum durum Desf. · Durum wheat
INIA-OTRI
Fragaria L. · Strawberry
Kopan Volodymyr Pavlovych, Kopan` Vira Mykolaivna,
Triticum aestivum L. · Bread wheat
AGRI-OBTENTIONS
Vitis vinifera L. · Common grape vine
SOMMA STEFANO
Rosa L. · Rose
Iuroaea Gheorghe
Cucumis melo L. · Melon
RAMIRO ARNEDO, S.A.
Beta vulgaris Sugar Beet Group · Sugar beet
VANDERHAVE SUGAR BEET B.V
Cucumis sativus L. · Cucumber
Ger Bimsdeboer
Malus domestica (Suckow) Borkh. · Apple
Toth Magdolna / Bodor Peter / Kovacs Szilvia
Vitis vinifera L. · Common grape vine
INCONNU (FR)