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.
Triticum durum Desf. · Durum wheat
Südwestdeutsche Saatzucht GmbH&Co.KG
Brassica napus L. var. napobrassica (L.) Rchb. · Rutabaga
DLF Seeds A/S, 4000 Roskilde
Cucumis sativus L. · Cucumber
GAVRISh SERGEJ FEDOROVICh / ShAMShINA ANNA VYaChESLAVOVNA / ShEVKUNOV VALERIJ NIKOLAEVICh / HOMChENKO NINA NIKOLAEVNA / MULYaR VALERIJ NIKOLAEVICh / KUREPIN ALEKSEJ VIKTOROVICh
Brassica napus L. var. napobrassica (L.) Rchb. · Rutabaga
PENDING
Cucumis melo L. · Melon
NUNHEMS
Solanum lycopersicum L. · Tomato
Martjin van Stee
Pisum sativum L. · Pea
Holland-Select Research B.V.
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Solanum lycopersicum L. · Tomato
Seminis Vegetable Seeds
Cucumis melo L. · Melon
Hazera Seeds, ISR
Triticum durum Desf. · Durum wheat
Florimond Desprez Veuve & Fils S.A.S
Hordeum vulgare L. · Barley
Victor Desprez
Lactuca sativa L. · Lettuce
Nunhems B.V., 6083 AB Nunhem
Trifolium pratense L. · Red clover
Beat Boller
Triticum aestivum L. · Bread wheat
LIMAGRAIN EUROPE
x Triticosecale Wittm. ex A. Camus · Triticale
CREA-GB, Limagrain Italia S.p.a.
Triticum aestivum L. · Bread wheat
Limagrain Europe S.A.S
Cucumis sativus L. · Cucumber
Rijk Zwaan Welver, D
Poa pratensis L. · Kentucky bluegrass
PICKSEED WEST INC
Hordeum vulgare L. · Barley
Anja Maasberg
Triticum aestivum L. · Bread wheat
KWS MOMONT RECHERCHE SARL, FR
Triticum aestivum L. · Bread wheat
Limagrain Europe S.A.S
Hordeum vulgare L. · Barley
KWS UK LTD
Triticum aestivum L. · Bread wheat
KWS UK LTD