Dee Scribe
ActiveCucumis sativus L. · Cucumber
Enza Zaden Beheer B.V.
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
Enza Zaden Beheer B.V.
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SEMILLAS FITO, S.A.
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SEMILLAS FITO, S.A.
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HORAL JIRI / ALEKSEEV YuRIJ BORISOVICh
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Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Vitis L. · Grapevine
GOLODRIGA PAVEL YaKOVLEVICh / USATOV VLADIMIR TROFIMOVICh / MAL'ChIKOV YuRIJ ALEKSANDROVICh / KIREEVA LYuDMILA KONSTANTINOVNA / DUBOVENKO NEONILA PETROVNA / RAZUVAEV NIKOLAJ IVANOVICh
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Lyfenko Lina Semenivna, Fedchenko Volodymyr Pavlovych, Bosakovska Nataliia IUriivna, Rodenko Halyna Anatoliivna, Shpykuliak IEvhenii Anatoliiovych, Narhan Tetiana Pavlivna, Nakonechnyi Mykola IUriiovych, Yeryniak Mykola Ivanovych, Lyfenko Savelii Pylypovy
Cucumis melo L. · Melon
HM Clause SA (FR)
Cucurbita pepo L. · Field pumpkin
Sakata Seed Sudamerica Ltd (BR)
Cucumis sativus L. · Cucumber
MERIDIEM SEEDS S.L.
Solanum lycopersicum L. · Tomato
Gautier Semences SAS (FR)
Daucus carota L. · Carrot
Vilmorin SA (FR)
Cucurbita pepo L. · Field pumpkin
Gautier Semences SAS (FR)
Cucurbita pepo L. · Field pumpkin
Gautier Semences SAS (FR)
Triticum aestivum L. · Bread wheat
Michigan State University
Solanum lycopersicum L. · Tomato
Monsanto Vegetable IP Management B.V.
Cucumis sativus L. · Cucumber
Enza Zaden Beheer B.V.
Triticum aestivum L. · Bread wheat
SAULESCU NICOLAEITTU GHEORGHEITTU MARIANAMUSTATEA POMPILIUPETCU ELENATIANU MIHAELABALOTA MARIA
Beta vulgaris Garden Beet Group · Garden beet
Domaine Public (FR)