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
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Cucumis melo L. · Melon
HM.Clause S.A.S.
Cucumis melo L. · Melon
HM.Clause S.A.S.
Cucumis sativus L. · Cucumber
Uniseeds, NL
Cucumis melo L. · Melon
HM.Clause S.A.S.
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Daucus carota L. · Carrot
Vilmorin-Mikado S.A.S.
Triticum aestivum L. · Bread wheat
Hodowla Roslin Strzelce Sp z.o.o. Grupa IHAR
Triticum aestivum L. · Bread wheat
Verneuil Recherche SA (FR)
Cucumis sativus L. · Cucumber
Bayer Holland B.V.
Vicia villosa Roth · Hairy vetch
SEMILLAS BATLLE, S.A.
Triticum aestivum L. · Bread wheat
Lietuvos agrarinių ir miškų mokslų centras
Triticum aestivum L. · Bread wheat
MOLDOVAN VASILEBOTEZAN VALERMOLDOVAN MARIAKADAR ROZALIATUSA SIMION
Capsicum annuum L. · Bell pepper
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Valerianella locusta (L.) Laterr. · Corn salad
Clause Semences SA (FR)
Cucumis sativus L. · Cucumber
Pascal Wanten
Beta vulgaris Sugar Beet Group · Sugar beet
SYNGENTA SEEDS, A.B.
Hordeum vulgare L. · Barley
Boreal Plant Breeding
Cucurbita pepo L. · Field pumpkin
ISP QUEDLINBURG GERMANY
x Triticosecale Wittm. ex A. Camus · Triticale
Florimond Desprez Veuve et Fils, FR
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Malus domestica (Suckow) Borkh. · Apple
Institut Français des Productions Cidricoles (I.F.P.C.), Institut National de Recherche pour l'Agriculture l'Alimentation et l'Environnement (INRAE)
Triticum aestivum L. · Bread wheat
Danko Hodowla Roslin Sp.z.o.o.
Cucumis sativus L. · Cucumber
Enza Zaden Beheer