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Diseases

Powdery mildew

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.

Sources10

Breakdown by crop

Found in these crops

Varieties that feature this in their description

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.

Merlot

Active

Echinacea purpurea (L.) Moench · Purple coneflower

Korlipara Harini|Canby, OR, US

2 records

Merlin

Terminated

Verbascum epixanthinum x Verbascum phoeniceum L.

Claire Wilson

2 records

Rosa L. · Rose

Meilland Alain A.

3 records

Fragaria x ananassa Duchesne ex Rozier · Garden strawberry

NIAB EMR

2 records

Fragaria x ananassa Duchesne ex Rozier · Garden strawberry

NIAB EMR

3 records

Rosa L. · Rose

Alain Antoine Meilland

2 records

MVNC1902

Active

Coreopsis grandiflora Hogg ex Sweet · Large-flowered tickseed

van Noort Marco

3 records

Rosa L. · Rose

Alain Antoine Meilland

2 records

Lilla

Active

Cotinus coggygria Scop. · European smoketree

Miklós Józsa

2 records

Nogeone

Active

Geranium wallichianum D. Don ex Sweet · Wallich's geranium

Marco van Noort Breeding B.V.

2 records

MD02UNIBO

Application submitted

Malus domestica (Suckow) Borkh. · Apple

Roberto Gregori,Silviero Sansavini,Stefano Tartarini

2 records

Triticum aestivum L. · Bread wheat

Limagrain Europe S.A.S

3 records

Lennon

Active

Avena sativa L. · Oat

ABERYSTWYTH UNIVERSITY

3 records

Humulus lupulus L. · Common hop

Roger D Jeske

2 records

Fragaria x ananassa Duchesne ex Rozier · Garden strawberry

NIAB EMR

3 records

MVNC1904

Active

Coreopsis grandiflora Hogg ex Sweet · Large-flowered tickseed

van Noort Marco

2 records

Pulmonaria L. · Lungwort

TERRA NOVA NURSERIES INC

2 records

LAGE001

Active

Lagerstroemia indica L. · Crape myrtle

Geert Devriese

2 records

Cercis canadensis L. · Eastern redbud

Woody Paul Buddy Ewing|Morganton, NC 28655

2 records

Midnight

Active

Heuchera L. · Coral Flower

The Behnke Nurseries Co.

2 records

Monarda didyma L. · Bee balm

Henricus Maria Joseph Holtmaat

2 records

Mckay

Active

Hydrangea macrophylla (Thunb.) Ser. · Bigleaf hydrangea

Thomas J. Buechel

2 records

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