Plagu Blue
Protection expiredDelphinium L. · Larkspur
KUNIHIRO KONISHI
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.
Delphinium L. · Larkspur
KUNIHIRO KONISHI
Humulus lupulus L. · Common hop
Peter Darby
Phlox paniculata L. · Garden phlox
Verschoor Jan|Haarlem 2015 CS, NL
Monarda L. · Bee balm
Hansen Hans A
Pulmonaria L. · Lungwort
TERRA NOVA NURSERIES INC
Penstemon Schmidel. · Beard Tongue
Syngenta Crop Protection AG
Nepeta x faassenii Bergmans ex Stearn · Faassen's catnip
MICHAEL S DOBRES
Monarda L. · Bee balm
Holtmaat Henricus Maria Joseph
Vitis vinifera L. · Common grape vine
Marco Stefanini Fondazione Edmund Mach (FEM-CRI)
Pisum sativum L. · Pea
PURE LINE SEEDS
Phlox paniculata L. · Garden phlox
Verschoor Jan|Haarlem, NL
Phlox paniculata L. · Garden phlox
Hansen Hans A
Coreopsis grandiflora Hogg ex Sweet · Large-flowered tickseed
van Noort Marco
Pulmonaria L. · Lungwort
TERRA NOVA NURSERIES INC
Quercus robur L. x Quercus macranthera Fisch. & C. A. Mey. ex Hohen.
Uniwersytet im. Adama Mickiewicza - Ogrod Botaniczny
Monarda didyma L. · Bee balm
Henricus Maria Joseph Holtmaat
Tiarella L. · Foamflower
TERRA NOVA NURSERIES INC
Deutzia gracilis Siebold & Zucc. · Japanese Snowflower
Hortival Diffusion SAS
Astilbe chinensis (Maxim.) Franch. & Sav. · Chinese astilbe
Henricus G.J. Verduin
Rosa L. · Rose
Meilland Alain A.
Rosa L. · Rose
Meilland Alain A.|Antibes, FR
Rosa L. · Rose
Meilland International
Pulmonaria L. · Lungwort
TERRA NOVA NURSERIES INC
Rosa L. · Rose
Alain Antoine Meilland