Rustica
ActiveMalus domestica (Suckow) Borkh. · Apple
Markus Kellerhals Agroscope
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.
Malus domestica (Suckow) Borkh. · Apple
Markus Kellerhals Agroscope
Zinnia x marylandica D. M. Spooner et al.
Sakata Ornamentals Europe A/S
Malus domestica (Suckow) Borkh. · Apple
Phlox paniculata L. · Garden phlox
Van Gaalen Irenaeus Antonius Maria
Rosa L. · Rose
William J. Radler
Rosa L. · Rose
Poulsen Roser A/S
Hylotelephium telephium (L.) H. Ohba · Orpine
Janet N. Egger
Acer campestre L.
Boomkwekerij L.B. Ruijgrok V.O.F.
Hibiscus moscheutos L. · Crimson-eyed rose mallow
Fleming's Flower Fields Inc.
Avena sativa L. · Oat
RAGT 2N S.A.S
Photinia serratifolia (Desf.) Kalkman
Jean-Pierre Faure
Humulus lupulus L. · Common hop
Anton Lutz^^^Herbert Ehrmaier
Vitis L. · Grapevine
HÖHERE BUNDESLEHRANSTALT UND BUNDESAMT FÜR WEIN UND OBSTBAU
Petunia Juss. · Petunia
TSUKAHARA JUN
Gaillardia x grandiflora hort. ex Van Houtte · Blanket flower
Korlipara Harini
Rosa L. · Rose
Poulsen Roser A/S
Humulus lupulus L. · Common hop
Peter Darby
Vitis vinifera L. · Common grape vine
Andor Szabó^^^Pál Kozma^^^Sarolta Hoffmann
Vitis L. · Grapevine
Valentin Blattner
Malus domestica (Suckow) Borkh. · Apple
Markus Kellerhals
Vitis L. · Grapevine
HÖHERE BUNDESLEHRANSTALT UND BUNDESAMT FÜR WEIN UND OBSTBAU
Rosa L. · Rose
Poulsen Roser A/S
Rosa L. · Rose
William J. Radler
Malus domestica (Suckow) Borkh. · Apple