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.
Solanum lycopersicum L. · Tomato
Enza Zaden Beheer B.V.
Triticum aestivum L. · Bread wheat
Strube D&S GMBH
Vitis L. · Grapevine
INCONNU (FR)
x Triticosecale Wittm. ex A. Camus · Triticale
Danko Hodowla Roslin Sp.z.o.o.
Triticum aestivum L. · Bread wheat
ShAMANIN VLADIMIR PETROVICh / P'YaNOV VLADIMIR PANTELEEVICh / KOLMAKOV YuRIJ VLADIMIROVICh / LEONT'EV SERAFIM IVANOVICh / HRAMTSOVA NATAL'Ya VASIL'EVNA / SERYuKOV GERMAN MIHAJLOVICh / GOLOVKO GALINA VLADIMIROVNA
Vitis L. · Grapevine
GUIDO CIPRIANI/GABRIELE DI GASPERO/MICHELE MORGANTE/ENRICO PETERLUNGER/RAFFAELE TESTOLIN/ SIMONE DIEGO CASTELLARIN
Capsicum annuum L. · Bell pepper
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Raphanus sativus L. var. sativus · Radish
Ger Beemsterboer
Cucumis sativus L. · Cucumber
Matthijs Groot
Cucumis sativus L. · Cucumber
SEMILLAS FITO, S.A.
Hordeum vulgare L. · Barley
Stefan Streng
Beta vulgaris Sugar Beet Group · Sugar beet
KWS SAAT SE and CO KGAA
Lactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Pisum sativum L. · Pea
SELGEN A.S
Triticum aestivum L. · Bread wheat
Svensson, Gunnar/Jönsson, Jan Ö.
Cucumis sativus L. · Cucumber
ZKI, H
Hordeum vulgare L. · Barley
Nordic Seed A/S
Solanum lycopersicum L. · Tomato
Enza Zaden Beheer B.V.
Malus domestica (Suckow) Borkh. · Apple
Prof. Dr. Manfred Fischer / Heinz Murawski + im Institut für Obstforschung Dresden-Pillnitz / Prof. Dr. Christa Fischer
Ribes uva-crispa L. · Gooseberry
Peter Hauenstein
Helianthus annuus L. · Sunflower
RAGT Czech s.r.o.,CZ
Triticum aestivum L. · Bread wheat
RAGT 2N S.A.S
Cucumis melo L. · Melon
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Cucumis melo L. · Melon
HAZERA (1939)