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.
Chrysanthemum x morifolium Ramat. · Florist's daisy
LAYNG| W. John Layng c/o Layng and Company Greenhouses
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Cucurbita moschata Duchesne · Butternut squash
Sokolova Viktoriia Kostiantynivna
Prunus persica (L.) Batsch var. nucipersica (Suckow) C. K. Schneid. · Nectarine
Latsko Tetiana Anatoliivna, Shoferistov IEvheniia Hryhorivna, Shoferistov IEvhenii Petrovych,
Beta vulgaris Garden Beet Group · Garden beet
Sakata Vegetabels Europe, F
Ribes nigrum L. · Blackcurrant
Lietuvos agrarinių ir miškų mokslų centro filialas Sodininkystės ir daržininkystės institutas
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Cucumis sativus L. · Cucumber
FGUP ,,Volgogradsortsemovošč"
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Calluna vulgaris (L.) Hull · Common heather
KERSKI| Manfred Kerski
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Fragaria L. · Strawberry
Horticulture Research International| GB
Malus domestica (Suckow) Borkh. · Apple
ROJA spółka z o.o. w upadłości likwidacyjnej
Malus domestica (Suckow) Borkh. · Apple
Toth Magdolna / Bodor Peter
Triticum aestivum L. · Bread wheat
RAGT 2n, FR
Triticum aestivum L. subsp. aestivum · Bread wheat
STRASS| Dr. Friedrich Strass in Bayerische Landesanstalt fuer Bodenkultur / ZIMMERMANN IN| Dr. G. Zimmermann in Bayerische Landesanstalt fuer
Ribes rubrum L. · Redcurrant
Szkółka Drzew i Krzewów Roman Buła
Vitis vinifera L. · Common grape vine
Maliukina Nina Anatoliivna, Mazurenko Liudmyla Stepanivna, Kovalova Iryna Anatoliivna, Chysnikov Vitalii Stepanovych, Tulaieva Maiia Ivanivna,
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Malus domestica (Suckow) Borkh. · Apple
Instytut Ogrodnictwa - Państwowy Instytut Badawczy
Begonia x hiemalis Fotsch · Elatior Begonia
MAN| J. Man
Triticum durum Desf. · Durum wheat
RAGT 2n, FR
Vitis vinifera L. · Common grape vine
INCONNU (FR)