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.
Solanum lycopersicum L. · Tomato
Syngenta Seeds B.V.
Avena strigosa Schreb. · Black oat
J. Joordens' Zaadhandel B.V.
Avena sativa L. · Oat
Serasem S.A.S.
Beta vulgaris Sugar Beet Group · Sugar beet
Lindroos Erik
x Triticosecale Wittm. ex A. Camus · Triticale
Stephanie Franck
Secale cereale L. · Rye
Erhardt Eger per adresse Pflanzenzucht Dr. h.c. Carsten, Inh. Erhardt Eger KG
Cucumis melo L. · Melon
Franck de Langen
Glycine max (L.) Merr. · Soybean
First Line Seeds Ltd (CA)
Cucumis sativus L. · Cucumber
OOO 'AGROFIRMA PARTNER'
Triticum aestivum L. · Bread wheat
Danko Hodowla Roslin Sp.z.o.o.
Beta vulgaris Sugar Beet Group · Sugar beet
Dr. Herman Strube
Triticum aestivum L. · Bread wheat
Sejet Planteforaedling I,S
Triticum aestivum L. · Bread wheat
KWS UK LTD
Trifolium pratense L. · Red clover
M. Strukcinskas, A. Svirskis,
Hordeum vulgare L. · Barley
Roothaan, M.E.
Cucumis sativus L. · Cucumber
Zoldsegtermesztesi Kutato Intezet, H
Cucumis sativus L. · Cucumber
Monsanto Vegetable IP Management B.V.
Solanum lycopersicum L. · Tomato
Kees Konst
Triticum durum Desf. · Durum wheat
SEMILLAS BATLLE, S.A.
x Triticosecale Wittm. ex A. Camus · Triticale
Norbert Starck^^^Peter Franck
Cucumis sativus L. · Cucumber
Matthijs Groot
Triticum durum Desf. · Durum wheat
Sudwestsaat GmbH (DE)
Cucumis sativus L. · Cucumber
RIJK ZWAAN Zaadteelt en Zaadhandel B.V.
Cucumis sativus L. · Cucumber
John Pieter Schipper