WSH 39-1046 AN
ActiveCucumis melo L. · Melon
Seminis Vegetable Seeds
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.
Cucumis melo L. · Melon
Seminis Vegetable Seeds
Helianthus annuus L. · Sunflower
MAS SEEDS
x Triticosecale Wittm. ex A. Camus · Triticale
NORDSAAT Saatzuchtgesellschaft mit beschränkter Haftung Herrn Dr. Ralf Schachschneider
Rosa L. · Rose
TANTAU NACH| Rosen Tantau Mathias Tantau Nachfolger
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Shahrokh Khanizadeh
Cucumis sativus L. · Cucumber
Monsanto Vegetable IP Management B.V.
Avena sativa L. · Oat
Sebastien Cuvelier, RAGT 2n
Triticum aestivum L. · Bread wheat
Hybrinova Sa (FR)
x Triticosecale Wittm. ex A. Camus · Triticale
Institut National de la Recherche Agronomique I.N.R.A.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
THOMAS M/AMADO Q./JOSPH I
Heuchera L. · Coral Flower
Blooms of Bressingham Ltd
Malus domestica (Suckow) Borkh. · Apple
Wageningen Plant Research, NL
Poa pratensis L. · Kentucky bluegrass
PURE SEED TESTING
Pisum sativum L. · Pea
Syngenta Participations AG
Triticum aestivum L. · Bread wheat
HANS WINZELER
Salvia L. · Sage
Wendy Smith
Hydrangea macrophylla (Thunb.) Ser. · Bigleaf hydrangea
Michael Dirr
Rosa L. · Rose
Hans Jurgen Evers
Helianthus annuus L. · Sunflower
MAS SEEDS
Helianthus annuus L. · Sunflower
Roberto Juan Reid
Triticum aestivum L. · Bread wheat
Borislav Kobiljski
Pisum sativum L. · Pea
Institute of field and vegetable crops - Novi Sad (SR)
Trifolium pratense L. · Red clover
Rijksstation Voor Plantenveredeling (BE)
Beta vulgaris Sugar Beet Group · Sugar beet
Betaseed Inc. (US)