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.
Rosa L. · Rose
Wilhelm Kordes,Tim-Hermann Kordes,Margarita Kordes
Triticum aestivum L. · Bread wheat
REINER BOTHE
Hordeum vulgare L. · Barley
KWS Lochow
Aster L. · Aster
PJF Akerboom
Rosa L. · Rose
Wilhelm Kordes, W Kordes' Sohne
Vicia faba L. · Broad bean
Norddeutsche Pflanzenzucht Hans-Georg Lembke KG
Triticum aestivum L. · Bread wheat
LIMAGRAIN EUROPE
Rosa L. · Rose
Wilhelm Kordes,Tim-Hermann Kordes,Margarita Kordes
Hordeum vulgare L. · Barley
Limagrain Europe S.A.S
Hordeum vulgare L. · Barley
Limagrain UK
Cucumis melo L. · Melon
Enza Zaden Beheer B.V.
Pisum sativum L. · Pea
Seminis Vegetable Seeds
Hordeum vulgare L. · Barley
KWS Lochow
Rosa L. · Rose
William A. Warriner c/o Jackson & Perkins Co
Lolium perenne L. · Perennial ryegrass
RAGT 2N S.A.S
Pisum sativum L. · Pea
Syngenta Crop Protection AG
Hordeum vulgare L. · Barley
SAATZUCHT JOSEF BREUN GMBH and CO.KG
Triticum aestivum L. · Bread wheat
KWS UK LTD
Hordeum vulgare L. · Barley
KWS MOMONT RECHERCHE SARL, FR
Hordeum vulgare L. · Barley
KWS Lochow
Hordeum vulgare L. · Barley
Sejet Planteforaedling I,S
Pisum sativum L. · Pea
Paul Degreef
Hordeum vulgare L. · Barley
W. von Borries-Eckendorf GmbH & Co.KG
Hordeum vulgare L. · Barley
SECOBRA RECHERCHES S.A.S