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.
x Triticosecale Wittm. ex A. Camus · Triticale
Danko Hodowla Roslin Sp z.o.o. (PL)
Cucumis sativus L. · Cucumber
Shevchenko Igor
Secale cereale L. · Rye
Danko Hodowla Roslin Sp.z.o.o.
Triticum durum Desf. · Durum wheat
RAGT 2n
Cucumis melo L. · Melon
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Petroselinum crispum (Mill.) Nyman ex A. W. Hill · Parsley
Domaine Public (FR)
Avena sativa L. · Oat
Wiersum Plantbreeding B.V.
Beta vulgaris Sugar Beet Group · Sugar beet
Margaret Rekoske
Ribes uva-crispa L. · Gooseberry
Triticum aestivum L. · Bread wheat
APSOVSEMENTI S.P.A.
Hordeum vulgare L. · Barley
Nilsson, Bengt
Triticum aestivum L. · Bread wheat
Svensson, Gunnar/Lundin, Per
Rosa L. · Rose
Poulsen Roser Aps (DK)
x Triticosecale Wittm. ex A. Camus · Triticale
Muranyi Istvan / Muranyi Nora
Rosa L. · Rose
Rosen-Tantau Mathias Tantau Nachfolger
Avena sativa L. · Oat
Výzkumné Centrum Selton s.r.o., Selgen A.S.
Chrysanthemum L. · Chrysanthemum
Vandenberg Cornelis P
Cucumis sativus L. · Cucumber
Yost van den Eiden
Triticum aestivum L. · Bread wheat
SW Seed BV
Rosa L. · Rose
TANTAU NACH| Rosen Tantau Mathias Tantau Nachfolger
Rosa L. · Rose
TANTAU NACH| Rosen Tantau KG
Triticum aestivum L. · Bread wheat
NORDSAAT SAATZUCHT
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
RONALD JOHN MCNICOL
Cucumis sativus L. · Cucumber
Zeraim Gedera Ltd (IL)