Starshine
ActiveAster ageratoides Turcz.
Praktijkonderzoek Plant en Omgeving 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.
Aster ageratoides Turcz.
Praktijkonderzoek Plant en Omgeving B.V.
Rosa L. · Rose
CHRISTIAN EVERS
Pisum sativum L. · Pea
PURE LINE SEEDS
Pulmonaria L. · Lungwort
Hansen Hans A
Verbena L. · Vervain
Yomo Yasunori|Takamura Naoto
Coreopsis L. · Tickseed
Probst Darrell R
Rosa L. · Rose
CHRISTIAN EVERS
Lolium multiflorum Lam. · Italian ryegrass
RAGT 2N S.A.S
Verbena L. · Vervain
Tomoya Misato, Takeshi Kanaya
Zinnia x marylandica D. M. Spooner et al.
Sakata Seed Corporation (SCC)
Triticum aestivum L. · Bread wheat
Limagrain UK
Cucumis sativus L. · Cucumber
PRIDNESTROVSKIJ NIISX
Pulmonaria L. · Lungwort
Janet N. Egger
Monarda L. · Bee balm
Oudshoorn Hubertus Gerardus
Triticum aestivum L. · Bread wheat
ASUR Plant Breeding S.A.S
Pittosporum tenuifolium Gaertn. · Kohuhu
Mark Fyfe^^^Rachelle Fyfe
Triticum aestivum L. · Bread wheat
Nickerson International Research S.N.C.
Zinnia x marylandica D. M. Spooner et al.
SHINJI MINEMURA
Brassica napus var. napus · Rapeseed
FORAGE INNOVATIONS LTD
Impatiens L. · Balsam
Sakata Seed Corporation (SCC)
Triticum aestivum L. · Bread wheat
Syngenta Participations AG
Triticum aestivum L. · Bread wheat
RAGT 2N S.A.S
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Nir Dai^^^Zecharia Tanami^^^Edna Ben Arie^^^Michal Barzilai
Berberis thunbergii DC. · Japanese barberry
Castanet Christian-Maurice