RUIRBM009B
WithdrawnRosa L. · Rose
De Ruiter Intellectual Property B.V.
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.
Rosa L. · Rose
De Ruiter Intellectual Property B.V.
Hybrids between Echinacea purpurea (L.) Moench and Echinacea paradoxa (Norton) Britton
HARINI KORLIPARA
Helenium L. · Sneezeweed
Inspiration Plant C.V.
Rosa L. · Rose
Jens Jorgensen
Vitis vinifera L. · Common grape vine
Gabriele Di Gaspero^^^Guido Cipriani^^^Simone Diego Castellarin^^^Michele Morgante^^^Enrico Peterlunger^^^Raffaele Testolin
Ribes uva-crispa L. · Gooseberry
Zinnia x marylandica D. M. Spooner et al.
Sakata Seed Corporation (SCC)
Vitis vinifera L. · Common grape vine
Vivai Cooperativi di Rauscedo (VCR)
Verbena L. · Vervain
Syngenta Seeds B.V.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Fresh Forward Holding B.V.
Pulmonaria longifolia (T. Bastard) Boreau x Pulmonaria saccharata Mill.
Vicenta Herrera Berdejo
Verbena L. · Vervain
GOLDSMITH SEEDS
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
ABZ Aardbeien uit Zaad Holding B.V.
Hydrangea aspera Buch.-Ham. ex D. Don · Rough-leaved hydrangea
Maurice C. Foster
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Stefan Kraege
Phlox x procumbens Lehm.
Ushio Sakazaki
Zinnia x marylandica D. M. Spooner et al.
Sakata Seed Corporation (SCC)
Zinnia x marylandica D. M. Spooner et al.
Sakata Ornamentals Europe A/S
Phlox x procumbens Lehm.
Ushio Sakazaki
Coreopsis L. · Tickseed
DARRELL R.PROBST
Zantedeschia Spreng. · Arum-lily
Sande B.V.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Johannes Øydvin, Norway
Verbena L. · Vervain
Syngenta Seeds B.V.
Rosa L. · Rose
William J. Radler