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
Jönsson, Jan Ö/Svensson, Gunnar/Lundin, Per
Lactuca sativa L. · Lettuce
Domaine Public (FR)
Ribes nigrum L. · Blackcurrant
Instytut Sadownictwa i Kwiaciarstwa im. Szczepana Pieniążka
Lilium L. · Lily
Mak Breeding Rights B.V./Arroyo Rights B.V.
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Triticum aestivum L. subsp. aestivum · Bread wheat
LUNDIN| Dr. Per Lundin c/o W. Weibull AB / JOENSSON JAN| Jan Oe Joensson c/o W. Weibull AB / SVENSSON| Gunnar Svensson c/o W. Weibull AB
Triticum aestivum L. · Bread wheat
CO.SE.ME. S.R.L.
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Lolium x hybridum Hausskn. · Hybrid ryegrass
J. Joordens Zaadhandel B.V. (NL)
Triticum aestivum L. · Bread wheat
Bertrand Schuling
Daucus carota L. · Carrot
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Lathyrus tingitanus L. · Gypsy Sweet Pea
SPAETH HANS| Dr. Hans Rolf Spaeth
Triticum aestivum L. · Bread wheat
NICKERSON GEIE
Triticum aestivum L. subsp. aestivum · Bread wheat
SEMUNDO| SW Seed GmbH
Triticum aestivum L. · Bread wheat
ERIK TYBIRK
Cucumis melo L. · Melon
Angeles Maria
Cucurbita moschata Duchesne · Butternut squash
Domaine Public (FR)
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Triticum aestivum L. subsp. aestivum · Bread wheat
RAGT2n Herrn Hilmar Cöster
Trifolium pratense L. · Red clover
Saatzucht Steinach GmbH (DE)
Cucumis melo L. · Melon
MERIDIEM SEEDS S.L.
Fragaria L. · Strawberry
ARCUTI P. / FAEDI WALTER / ROSATI PASQUALE
Ribes nigrum L. · Blackcurrant
Instytut Sadownictwa i Kwiaciarstwa im. Szczepana Pieniążka
Solanum lycopersicum L. · Tomato
HM.CLAUSE