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.
Poa pratensis L. · Kentucky bluegrass
Lietuvos agrarinių ir miškų mokslų centro filialas Žemdirbystės institutas
Lactuca sativa L. · Lettuce
Syngenta Seeds B.V.
Triticum durum Desf. · Durum wheat
Saatzucht Donau GmbH & Co.KG
Linum usitatissimum L. · Common flax
Linéa Semences de Lin G.I.E.
Hordeum vulgare L. · Barley
Sejet Planteforaedling I,S
Cucumis sativus L. · Cucumber
Enza Zaden, NL
Malus Mill. · Apple
Frank H. Alston Institute of Horticultural Research
Hordeum vulgare L. · Barley
Syngenta UK Ltd
Cucumis melo L. · Melon
W. LEGUTKO PRZEDSIEBIORSTWO HODOWLANO NASIENNE SP.Z.O.O
Brassica rapa L. subsp. pekinensis (Lour.) Hanelt · Napa cabbage
BEJO ZADEN B.V.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
UNIVERS. OF FLORIDA
Avena sativa L. · Oat
Landwirtschaftliche Fachschule Edelhof Saatzucht
Solanum lycopersicum L. · Tomato
ENZA ZADEN BEHEER B.V.
Begonia x tuberhybrida Voss · Tuberous begonia
Kliem Erich
Triticum aestivum L. subsp. spelta (L.) Thell. · Spelt
Saatzucht Ebnerhof Hans Gahleitner, Maria Grünbacher, Josef
Hordeum vulgare L. · Barley
Saatzucht Edelhof
Triticum aestivum L. · Bread wheat
Landwirtschaftliche Fachschule Edelhof Saatzucht
Hordeum vulgare L. · Barley
Syngenta Participations AG
Triticum aestivum L. · Bread wheat
SECOBRA RECHERCHES S.A.S
Cucumis melo L. · Melon
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Triticum durum Desf. · Durum wheat
Saatzucht Donau GmbH & Co.KG
Lolium perenne L. · Perennial ryegrass
AFBI
Daucus carota L. · Carrot
Nunhems, NL
Triticum durum Desf. · Durum wheat
Südwestdeutsche Saatzucht GmbH&Co.KG