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.
Cucurbita pepo L. · Field pumpkin
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Capsicum annuum L. · Bell pepper
RAMIRO ARNEDO, S.A.
x Triticosecale Wittm. ex A. Camus · Triticale
LEMAIRE DEFFONTAINES SEMENCES
Rosa L. · Rose
Klymenko Zinaida Kostiantynivna, Zykov Kostiantyn Ivanovych,
Lactuca sativa L. var. crispa L. · Leaf lettuce
Horova Tamara Korniivna, Khareba Olena Vasylivna, Pozniak Oleksandr Vasyl`ovych, Kondratenko Serhii Ivanovych, Nesyn Volodymyr Mykolaiovych, Korniienko Serhii Ivanovych, Tkalych IUrii Vadymovych,
Triticum aestivum L. · Bread wheat
Oksom Volodymyr Polikarpovych, Oksom Liudmyla Leonidivna, Morhun Volodymyr Vasylovych,
Camelina sativa (L.) Crantz · Camelina
KIS (SI)
Rosa L. · Rose
Richard Laperriere (Roseraie Laperriere) (FR)/Philippe Laperriere (Roseraie Laperriere) (FR)
Rosa L. · Rose
W. Kordes Sohne Rosenschulen GmbH & Co KG| DE
Triticum aestivum L. · Bread wheat
Dobroudja Agricultural Institute - General Toshevo (BG)
Hordeum vulgare L. · Barley
Solonechnyi Pavlo Mykolaiovych, Vazhenina Ol`ha IEvheniivna, Naumov Oleksii Hermanovych, Vasko Nataliia Ivanivna, Kozachenko Mykhailo Romanovych,
Cucurbita pepo L. · Field pumpkin
HAO-DEMETER Vine, Fruit Trees and Vegetable Research Institute
x Triticosecale Wittm. ex A. Camus · Triticale
Kovalchuk Serhii Oleksandrovych, Hirko Oleksandr Volodymyrovych, Holyk Liubov Mykolaivna, Kyryl`chuk Anzhela Mykolaivna, Starychenko Vasyl Mykolaiovych,
Rosa L. · Rose
KORDES' SOEHNE| W. Kordes' Soehne Rosenschulen GmbH & Co KG
Rosa L. · Rose
Robert Louis Laperriere (FR)
Cucumis sativus L. · Cucumber
Khokhlova Nataliia Oleksiivna, Ivanova Anna Pavlivna, Suchkova Liubov Vasylivna,
Cucumis sativus L. · Cucumber
Naumov Ruslan Olehovych, Krasniuk Viacheslav Anatoliiovych,
Capsicum annuum L. · Bell pepper
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Rosa L. · Rose
Philippe Laperriere (Roseraie Laperriere) (FR)/Richard Laperriere (Roseraie Laperriere) (FR)
Rosa L. · Rose
KORDES WILHELM| Wilhelm Kordes / KORDES TIM-HERMANN| Tim-Hermann Kordes / KORDES| Margarita Kordes in Fa. W. Kordes' Soehne Rosenschulen GmbH & Co KG
Vitis vinifera L. · Common grape vine
Mincho G. Kondarev
Spinacia oleracea L. · Spinach
Archipiano Murielle
Vitis vinifera L. · Common grape vine
Shein Tamara Volodymyrivna, Dylyk Antonina Petrivna, Storozhuk Kateryna Moisiivna, Tarakhtii Liudmyla Ivanivna, Chebanenko IEvheniia Pavlivna, Meleshko Larysa Fedorivna, Dokuchaieva IEvheniia Mykolaivna,
Secale cereale L. · Rye
Polinkevych Nataliia Levkivna, Vyshnevs`ka Oksana Vasylivna, Ratoshniuk Viktor Ivanovych, Ivaniuk Ol`ha IUriivna, Chernus`ka Tamara Andriivna, Chernus`kyi Vadym Viktorovych,