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.
x Triticosecale Wittm. ex A. Camus · Triticale
Peter Franck^^^Norbert Starck
Cucurbita pepo L. · Field pumpkin
VEGETABLE MONSANTO B.V.
Cucumis sativus L. · Cucumber
Yuksel Tohum, TR
Helianthus annuus L. · Sunflower
BORODIN SERGEJ GEORGIEVICh / ILATOVSKIJ VLADIMIR PLATONOVICh / DETSYNA ALEKSANDR ALEKSANDROVICh / PIGROVA SVETLANA KUZ'MINIChNA / POLTORAKA ALEKSANDR ALEKSEEVICh / BYaTETS VIKTOR IVANOVICh
Cucumis sativus L. · Cucumber
SEMILLAS FITO, S.A.
Medicago sativa L. · Alfalfa
Natura Srl
Beta vulgaris Sugar Beet Group · Sugar beet
SESVanderhave NV
Triticum aestivum L. · Bread wheat
WORLD WIDE WHEAT L.L.C.
Cucumis sativus L. · Cucumber
Nunhems B.V., Nunhems B.V.
x Triticosecale Wittm. ex A. Camus · Triticale
RAC Station federale de recherches agronomiques de Changins (CH)/Hybrinova Sa (FR)
Solanum lycopersicum L. · Tomato
Martjin van Stee
Cucurbita pepo L. · Field pumpkin
SEMILLAS FITO, S.A.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Walther Faedi^^^Gianluca Baruzzi^^^Pierluigi Lucchi^^^Paolo Sbrighi
Hordeum vulgare L. · Barley
Nickerson International Research S.N.C.
Begonia x hiemalis Fotsch · Elatior Begonia
LUBBERTUS H.KOPPE
Poa pratensis L. · Kentucky bluegrass
TURF-SEED INC
Secale cereale L. · Rye
SAATZUCHT STEINACH GMBH and CO KG
Linum usitatissimum L. · Common flax
Terre de Lin Sca (FR)
Secale cereale L. · Rye
HODOWLA ROSLIN SMOLICE SP.ZOO
Vitis vinifera L. · Common grape vine
JUAN CARREÑO ESPIN
Triticum aestivum L. · Bread wheat
Danko Hodowla Roslin Sp.z.o.o.
x Triticosecale Wittm. ex A. Camus · Triticale
Serasem S.A.S.
Triticum aestivum L. · Bread wheat
ELSOMS WHEAT
Triticum aestivum L. · Bread wheat
Graminor AS, N-2322 Ridabu