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.
Humulus lupulus L. · Common hop
Slovenian Institute of Hop Research and Brewing
Humulus lupulus L. · Common hop
Slovenian Institute of Hop Research and Brewing
Linum usitatissimum L. · Common flax
Linéa Semences de Lin G.I.E.
Cucurbita pepo L. · Field pumpkin
BURPEE NL B.V.
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Cucumis sativus L. · Cucumber
VEGETABLE MONSANTO B.V.
Secale cereale L. · Rye
Franz-Joachim Fromme
Triticum aestivum L. · Bread wheat
BESPALOVA LYuDMILA ANDREEVNA / PUZYRNAYa OL'GA YuR'EVNA / NOVIKOV ALEKSEJ VLADIMIROVICh / KERIMOV VAGIF RAHMETOVICh / ABLOVA IRINA BORISOVNA / LYSAK NIKOLAJ IVANOVICh / BUKREEVA GALINA IVANOVNA / KUDRYaShOV IGOR' NIKOLAEVICh / ZIMA VALENTINA GRIGOR'EVNA /
Poa pratensis L. · Kentucky bluegrass
DLF Pickseed USA, Inc. and Rutgers, The State University of New Jersey
Cucumis sativus L. · Cucumber
GAVRISh SERGEJ FEDOROVICh / PORTYaNKIN ALEKSEJ EVGEN'EVICh / ShAMShINA ANNA VYaChESLAVOVNA / ShEVKUNOV VALERIJ NIKOLAEVICh / HOMChENKO NINA NIKOLAEVNA / SUROVOVA TAT'YaNA YaKOVLEVNA / PLUZhNIK IVAN SERGEEVICh
Solanum lycopersicum L. · Tomato
Enza Zaden Beheer B.V.
Hordeum vulgare L. · Barley
Stefan Streng^^^Katrin Dengler
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Cucumis sativus L. · Cucumber
Monsanto Vegetable IP Management B.V.
Rosa L. · Rose
Starkl, Ludwig|Vienna, Austria
x Triticosecale Wittm. ex A. Camus · Triticale
Saaten-Union
Trifolium pratense L. · Red clover
Saatzucht Steinach GmbH & Co KG
Spinacia oleracea L. · Spinach
Cora Seeds, I
Pisum sativum L. · Pea
Syngenta Seeds B.V.
Solanum lycopersicum L. · Tomato
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Hordeum vulgare L. · Barley
Sejet Planteforaedling I,S
Triticum aestivum L. subsp. spelta (L.) Thell. · Spelt
Südwestdeutsche Saatzucht GmbH&Co.KG
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Poa pratensis L. · Kentucky bluegrass
Grassland Oregon