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.
Festuca pratensis Huds. · Meadow fescue
Barenbrug Holland B.V.
Beta vulgaris Sugar Beet Group · Sugar beet
WIELKOPOLSKA HODOWLA BURAKA CUKROWEGO SP.Z.O.O
Hordeum vulgare L. · Barley
Saatzucht Donau GmbH & Co.KG
Triticum aestivum L. · Bread wheat
LIMAGRAIN NEDERLAND
Pisum sativum L. · Pea
SATIVA VIA CALCINARO 2425
Cucumis melo L. · Melon
Clause Semences (FR)
Cucumis melo L. · Melon
Syngenta Seeds B.V. (NL)
Hordeum vulgare L. · Barley
SECOBRA RECHERCHES S.A.S
Triticum aestivum L. · Bread wheat
Saatzucht Donau, A
x Triticosecale Wittm. ex A. Camus · Triticale
LEMAIRE DEFFONTAINES S.A.S.
Cucumis sativus L. · Cucumber
MORAVOSEED
Pisum sativum L. · Pea
Danko Hodowla Roslin Sp.z.o.o.
Beta vulgaris Sugar Beet Group · Sugar beet
KWS SAAT SE&CO.KGaA, DE
Beta vulgaris Sugar Beet Group · Sugar beet
Strube-Dieckmann GmbH and Co.KG Dr. Hermann Strube
Cucumis melo L. · Melon
Sakata Vegetables Europe, F
Triticum aestivum L. · Bread wheat
SAATEN UNION RECHERCHE
Malus domestica (Suckow) Borkh. · Apple
University of Arkansas
Pisum sativum L. · Pea
Selgen, a.s. Vyzkumne centrum SELTON, s.r.o.
Cucumis sativus L. · Cucumber
Sakata Seed Corporation
Avena sativa L. · Oat
Saatzucht Bauer GmbH & Co KG
Triticum durum Desf. · Durum wheat
UCA SEM.PROVENCE
Hordeum vulgare L. · Barley
SAS FLORIMOND DESPREZ VEUVE and FILS
Cucumis sativus L. · Cucumber
BLINOVA Tatiana, MD STRLNICOVA Tamara, MD MASTACOVA Anna, MD
Solanum lycopersicum L. · Tomato
De Ruiter Zonen (HR)