Cranberry Lace
ActiveMonarda L. · Bee balm
Oudshoorn Hubertus Gerardus
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.
Monarda L. · Bee balm
Oudshoorn Hubertus Gerardus
Rubus L. subg. Rubus · Blackberry
Driscoll Strawberry Associates Inc.
Phlox paniculata L. · Garden phlox
Geerlings-Meyer
Rosa L. · Rose
Société Nouvelle Pépinières et Roseraies Georges Delbard S.A.S.
Hylotelephium telephium (L.) H. Ohba · Orpine
Janet N. Egger
Lagerstroemia L. · Crape Myrtle
Hansen Hans A
Rosa L. · Rose
Société Nouvelle Pépinières et Roseraies Georges Delbard S.A.S.
Hybrid between Astilbe x arendsii and Astilbe japonica
van de Meer Hans
Ajuga reptans L. · Bugle
Tristram Mike|Arundel, West Sussex BN18 0LL, GB
Hordeum vulgare L. · Barley
Claus Einfeldt
Coreopsis L. · Tickseed
Probst Darrell R
Tiarella L. · Foamflower
TERRA NOVA NURSERIES INC
Monarda didyma L. · Bee balm
Trees Scott
Vicia faba L. · Broad bean
Semillas Fitó S.A.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Michelangelo Leis^^^Alessio Martinelli
Lagerstroemia indica L. · Crape myrtle
Fleming's Flower Fields Inc.
Ribes nigrum L. · Blackcurrant
V. Kopan c/o Institute of Horticulture Research Centre
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Michelangelo Leis^^^Alessio Martinelli
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Alessio Martinelli^^^Michelangelo Leis
Triticum aestivum L. · Bread wheat
Dario Fossati Agroscope
Coreopsis L. · Tickseed
Winner Blair
Phlox paniculata L. · Garden phlox
van den Haak Jelle
Anemone hupehensis Lemoine · Japanese anemone
Yoshihiro Kanazawa
Phlox paniculata L. · Garden phlox
Kievit Christa