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 aestivum L. · Bread wheat
Cultivari Getreidezüchtungsforschung Darzau gGmbH
Hordeum vulgare L. · Barley
Instytut Hodowli i Aklimatyzacji Roslin Panstwowy Instytut Badawczy
Cucurbita pepo L. · Field pumpkin
Syngenta Seeds B.V.
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Glycine max (L.) Merr. · Soybean
R. Todorova, K. Goranova
Cucumis sativus L. · Cucumber
HM.CLAUSE
Triticum durum Desf. · Durum wheat
Saatzucht Donau GmbH & Co.KG
Chrysanthemum L. · Chrysanthemum
W JOHN LAYNG
Pisum sativum L. · Pea
Poznanska Hodowla Roslin Sp. z o.o
Hordeum vulgare L. · Barley
Hodowla Roslin Smolice Sp.z o.o Grupa IHAR
x Triticosecale Wittm. ex A. Camus · Triticale
RAGT 2N S.A.S
Lactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Hordeum vulgare L. · Barley
Hodowla Roslin Smolice Sp.z o.o Grupa IHAR
x Triticosecale Wittm. ex A. Camus · Triticale
RAGT 2N S.A.S
Prunus persica (L.) Batsch · Peach
Pisum sativum L. · Pea
Syngenta Seeds B.V.
x Triticosecale Wittm. ex A. Camus · Triticale
Stephanie Franck
Vitis vinifera L. · Common grape vine
INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE, FR
Triticum aestivum L. · Bread wheat
RAGT CZECH S.R.O.
Triticum aestivum L. · Bread wheat
RAGT 2N S.A.S
Triticum aestivum L. · Bread wheat
RAGT 2N S.A.S
Hordeum vulgare L. · Barley
Sejet Planteforaedling I,S
Cucumis melo L. · Melon
Syngenta Crop Protection AG
Pisum sativum L. · Pea
Syngenta UK Ltd