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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.

KORaruli

Active

Rosa L. · Rose

Margarita Kordes^^^Wilhelm Kordes^^^Tim-Hermann Kordes

4 records

Rosa L. · Rose

WILHELM-ALEXANDER KORDES

5 records

Itasca

Active

Vitis L. · Grapevine

Peter Hempstad

4 records

indycam

Active

Lagerstroemia indica L. · Crape myrtle

Lagerstroemia S.A.R.L.

4 records

Calibrachoa Cerv. · Calibrachoa

Losert Dominik

4 records

Itarzi

Active

Lolium multiflorum Lam. · Italian ryegrass

DLF SEEDS A/S

7 records

Harflow

Active

Rosa L. · Rose

Harkness, Robert|Mougins, France

5 records

JWW1

Active

Viburnum plicatum Thunb. · Japanese snowball

Wezelenburg Jan-Willem

4 records

indybra

Active

Lagerstroemia indica L. · Crape myrtle

Lagerstroemia S.A.R.L.

4 records

EVIfive

Active

Clematis L. · Clematis

RAYMOND J. EVISON^^^POULSEN ROSER INTERNATIONAL S.A.R.L.

4 records

Firefly

Active

Coreopsis L. · Tickseed

Korlipara Harini

5 records

Electra

Active

Heuchera L. · Coral Flower

Janet N. Egger

4 records

Fireball

Active

Monarda didyma L. · Bee balm

Oudshoorn Hubertus Gerardus

4 records

Heuchera L. · Coral Flower

Janet N. Egger

4 records

Clematis L. · Clematis

HAYAKAWA HIROSHI

4 records

Gipi Whit

Application submitted

Achillea ptarmica L.

ROBERT PIERCE

4 records

Eveline

Active

Salvia L. · Sage

Petrus Hendricus Oudolf

4 records

Oenothera lindheimeri (Engelm. & A. Gray) W. L. Wagner & Hoch · Lindheimer's beeblossom

Syngenta Seeds B.V.

4 records

ESM R057

Active

Rosa L. · Rose

Hooijman Aloysius A. J.

4 records

ESM R030

Active

Rosa L. · Rose

Hooijman Aloysius A. J.

4 records

Delilah

Active

Phlox paniculata L. · Garden phlox

Oudshoorn Hubertus Gerardus

4 records

Cocktail

Application submitted

Hordeum vulgare L. · Barley

Syngenta UK Ltd

5 records

Dely

Active

Fragaria x ananassa Duchesne ex Rozier · Garden strawberry

Leis Michelangelo/ Castagnoli Gianfranco/ Martinelli Alessio

7 records

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