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.
Ribes nigrum L. · Blackcurrant
Johannes Parksepp 50%, Asta Libek 50%
Cucurbita pepo L. · Field pumpkin
SEMILLAS FITO, S.A.
Triticum aestivum L. · Bread wheat
Hodowla Roslin Strzelce Sp z.o.o. Grupa IHAR
Malus domestica (Suckow) Borkh. · Apple
Szkola Glowna Gospodarstwa Wiejskiego
Capsicum annuum L. · Bell pepper
Enza Zaden Beheer B.V.
Cucumis melo L. · Melon
Clause (FR)
Triticum aestivum L. · Bread wheat
Lytvynenko Raisa Ivanivna, Dubinina Liudmyla Oleksiivna, Traskovetska Vita Anatoliivna, Vasyliev Oleksii Anatoliiovych, Babaiants Olha Vadymivna, Rybalka Oleksandr Illich, Ptashenchuk Oleksandr Mykytovych, Lytvynenko Mykola Antonovych, Babaiants Lazar Tih
Cucumis sativus L. · Cucumber
Syngenta Crop Protection AG
Vitis L. · Grapevine
JKI - Julius Kuhn Institut (DE)/Institut National de la Recherche Agronomique (FR)
Valerianella locusta (L.) Laterr. · Corn salad
Clause Semences SA (FR)
Vitis L. · Grapevine
INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE, FR
Cucumis melo L. · Melon
HM.Clause S.A.S.
Hordeum vulgare L. · Barley
STICHTING FONDS BVL.
Cucumis melo L. · Melon
HM Clause SA (FR)
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Solanum lycopersicum L. · Tomato
Enza Zaden Beheer B.V.
Cucumis sativus L. · Cucumber
Bayer Holland B.V.
Cucumis sativus L. · Cucumber
Zeraim Gedera Ltd (IL)
Cucumis melo L. · Melon
UNITED GENETICS SEEDS CO
Prunus persica (L.) Batsch · Peach
Malus domestica (Suckow) Borkh. · Apple
Pisum sativum L. · Pea
Poznanska Hodowla Roslin Sp. z o.o
Vitis L. · Grapevine
INCONNU (FR)
Capsicum annuum L. · Bell pepper
HAZERA SEEDS BV