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.
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Capsicum annuum L. · Bell pepper
INTERSEMILLAS SAU
Cucumis melo L. · Melon
Syngenta Crop Protection AG, CH
Cucumis melo L. · Melon
HM Clause SA (FR)
Cucumis melo L. · Melon
MERIDIEM SEEDS S.L.
Capsicum annuum L. · Bell pepper
MAGNUM SEEDS INC
Hordeum vulgare L. · Barley
LOCHOW-PETKUS
Cucumis melo L. · Melon
Clause Tezier, FR
Cucumis melo L. · Melon
SEMILLAS FITO, S.A.
Solanum lycopersicum L. · Tomato
Axia NL B.V.
Hordeum vulgare L. · Barley
SEMILLAS BATLLE, S.A.
Daucus carota L. · Carrot
Robert Maxwell
Cucumis melo L. · Melon
Nunhems B.V., Laboratoire ASL S.N.C.
Cucumis sativus L. · Cucumber
Instytut Ogrodnictwa - Państwowy Instytut Badawczy \Przedsiębiorstwo Nasiennictwa Ogrodniczego i Szkółkarstwa w Ożarowie Mazowieckim Spółka z o.o.
hybrids between Solanum lycopersicum L. and S. habrochaites S. Knapp & D.M. Spooner
CORA SEEDS S.R.L
Hordeum vulgare L. · Barley
SEMILLAS BATLLE, S.A.
Cucumis sativus L. · Cucumber
SPÓJNIA Hodowla i Nasiennictwo Ogrodnicze sp. z o.o.
Lactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Cucumis sativus L. · Cucumber
Nunhems B.V.
Cucumis melo L. · Melon
MERIDIEM SEEDS S.L.
x Triticosecale Wittm. ex A. Camus · Triticale
RAGT 2n
Triticum aestivum L. · Bread wheat
RAGT 2n
Cucumis melo L. · Melon
Nunhems B.V./Laboratioire ASL S.N.C.
Cucumis melo L. · Melon
Nunhems B.V.