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.
Vicia sativa L. · Common vetch
INDUSTRIAS AGRARIAS CASTELLANAS, S.A.-INDACSA
Cucumis melo L. · Melon
LEEN DE MOS ZADEN B.V.
Pisum sativum L. · Pea
Ardie G. Gustafson, Seedsman
Triticum aestivum L. · Bread wheat
PBI SAATZUCHT
Malus domestica (Suckow) Borkh. · Apple
SCHMIDT| Prof. Dr. Hanna Schmidt / SAURE| Dr. Max Saure
Cucumis sativus L. · Cucumber
SEMILLAS FITO, S.A.
Prunus persica (L.) Batsch · Peach
Beta vulgaris Fodder Beet Group · Mangelwurzel
VEREDELINGSSTATION AG
Cucurbita pepo L. · Field pumpkin
UNITED GENETICS ITALIA S.P.A
Cucumis sativus L. · Cucumber
SEMILLAS FITO, S.A.
Vitis vinifera L. · Common grape vine
Dimitar Babrikov, Venelin Roychev, Agricultural University - Plovdiv (BG)
Cucumis melo L. · Melon
Monsanto Vegetable IP Management B.V.
Avena sativa L. · Oat
INIA-OTRI
Capsicum annuum L. · Bell pepper
HM Clause SA (FR)
Lactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Malus domestica (Suckow) Borkh. · Apple
RATI IOAN VIOREL
Cucumis sativus L. · Cucumber
Vilmorin SA (FR)
Vitis L. · Grapevine
Doc. Ing. Miloš Michlovský, CSc. (CZ)
Triticum aestivum L. · Bread wheat
Strube Research GmbH&Co KG
Ribes nigrum L. · Blackcurrant
Estonian University of Life Sciences Institute of Agricultural and Environmental Sciences Polli Horticultural Research Centre
Cucumis sativus L. · Cucumber
Enza Zaden Beheer B.V.
Cucumis melo L. · Melon
SEMILLAS FITO, S.A.
Pisum sativum L. · Pea
GSN Semences SAS (FR)
Vitis L. · Grapevine
INCONNU (FR)