Parméo
ActiveLinum usitatissimum L. · Common flax
Linéa Semences de Lin G.I.E.
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.
Linum usitatissimum L. · Common flax
Linéa Semences de Lin G.I.E.
Helianthus annuus L. · Sunflower
STRUBE ESPAÑA, S.A.
Cucumis sativus L. · Cucumber
Nunhems B.V.
Triticum aestivum L. · Bread wheat
Malopolska Hodowla Roslin Spolka z o.o.
Triticum aestivum L. · Bread wheat
SAULESCU NICOLAEITTU GHEORGHEMUSTATEA POMPILIUITTU MARIANA
Cucumis melo L. · Melon
UNITED GENETICS SEEDS CO
Triticum aestivum L. · Bread wheat
DEUTSCHE SAATVEREDELUNG AG
Cucumis sativus L. · Cucumber
Monsanto Vegetable IP Management B.V.
Cucumis sativus L. · Cucumber
Nunhems B.V.
Cucurbita pepo L. · Field pumpkin
HM.Clause S.A.S.
Cucumis sativus L. · Cucumber
BURPEE NL B.V.
Capsicum annuum L. · Bell pepper
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Avena nuda L. · Naked oat
Selgen
Cucurbita pepo L. · Field pumpkin
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Pisum sativum L. · Pea
Van Waveren Saaten GmbH
Rosa L. · Rose
ROSERAIES GAUJARD
Triticum aestivum L. · Bread wheat
LIMAGRAIN NEDERLAND
Capsicum annuum L. · Bell pepper
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Cucumis melo L. · Melon
Enza Zaden Beheer B.V.
Daucus carota L. · Carrot
BEJO ZADEN
Allium fistulosum L. · Welsh onion
DE BERCKT 8
Triticum aestivum L. · Bread wheat
Orovcanec Ognen
Secale cereale L. · Rye
DANKO HODOWLA| "DANKO" Hodowla Roslin Sp. z o.o.