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.
Malus domestica (Suckow) Borkh. · Apple
Ústav experimentální botaniky AV ČR, v.v.i. (CZ)
Citrullus lanatus (Thunb.) Matsum. & Nakai · Watermelon
Dr Eyal Vardi
Cucurbita pepo L. · Field pumpkin
INTERSEMILLAS SAU
Cucumis sativus L. · Cucumber
Zaklad Ogrodniczy Przyborow sp. z o.o.
Solanum lycopersicum L. · Tomato
WESTERN SEED ESPAÑA, S.A.
Cucurbita pepo L. · Field pumpkin
Syngenta Seeds B.V.
Triticum aestivum L. · Bread wheat
Ihnatovskyi Oleksandr Oleksandrovych, Babaiants Olha Vadymivna, Khodakova Tetiana Mykolaivna, Parfentiev Mykhailo Hryhorovych, Lytvynenko Raisa Ivanivna, Maksymov Mykola Havrylovych, Lytvynenko Mykola Antonovych,
Malus domestica (Suckow) Borkh. · Apple
Instytut Ogrodnictwa - Państwowy Instytut Badawczy
Cucumis melo L. · Melon
NUNHEMS BIO OBTENTION
Triticum monococcum L. · Einkorn wheat
LEMAIRE DEFFONTAINES S.A.S.
Cucumis sativus L. · Cucumber
PLANTICO HODOWLA I NASIENNICTWO OGRODNICZE ZIELONKI SP. Z O.O.
Cucurbita pepo L. · Field pumpkin
SEMILLAS FITO, S.A.
Prunus persica (L.) Batsch · Peach
Reuter, Donald|Richwood, NJ
Petroselinum crispum (Mill.) Nyman ex A. W. Hill · Parsley
Nunhems Germany GmbH
Cucumis melo L. · Melon
UNITED GENETICS SEEDS CO
Prunus persica (L.) Batsch · Peach
Institute of Fruit Crops-Plovdiv
Solanum lycopersicum L. · Tomato
Graines Voltz (FR)
Cucurbita pepo L. · Field pumpkin
Gautier Semences SAS (FR)
Vitis L. · Grapevine
Doc. Ing. Miloš Michlovský, CSc. (CZ)
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Trajkovski, Viktor
Spinacia oleracea L. · Spinach
CHRESTENSEN N.L.| N.L. Chrestensen Erfurter Samen- und Pflanzen- zucht GmbH
Beta vulgaris Sugar Beet Group · Sugar beet
KWS SAAT SE & CO.KGAA
Solanum lycopersicum L. · Tomato
Gautier Semences SAS (FR)
Cucurbita pepo L. · Field pumpkin
Gautier Semences SAS (FR)