Melizar
ActiveCucumis melo L. · Melon
Nunhems 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.
Cucumis melo L. · Melon
Nunhems B.V.
Rosa L. · Rose
Meilland, Alain A.|Antibes, France
Vitis L. · Grapevine
GUIDO CIPRIANI / ENRICO PETERLUNGER / GABRIELE DI GASPERO / MICHELE MORGANTE / SIMONE DIEGO CASTELLARIN / RAFFAELE TESTOLIN
Hordeum vulgare L. · Barley
SEMILLAS BATLLE, S.A.
Lactuca sativa L. · Lettuce
HM.CLAUSE
Triticum durum Desf. · Durum wheat
MALIANI GENETICA SRL UNIPERSONALE
Daucus carota L. · Carrot
BEJO ZADEN B.V.
Cucumis sativus L. · Cucumber
DE RUITER SEEDS NL B.V.
Rosa L. · Rose
Meilland Alain A.|Antibes, FR
Rosa L. · Rose
Meilland, Alain A.|Antibes, France
Hordeum vulgare L. · Barley
Malopolska Hodowla Roslin Spolka z o.o.
Triticum durum Desf. · Durum wheat
Monsanto Agricultura España S.L.U.
Linum usitatissimum L. · Common flax
SCHNOCK MARTIN| Dr. Martin G. Schnock (+)
Cucumis sativus L. · Cucumber
Majstro Seeds B.V.
Hordeum vulgare L. · Barley
DEUTSCHE SAATVEREDELUNG AG
Cucumis sativus L. · Cucumber
Semo, CZ
Cucurbita moschata Duchesne · Butternut squash
Sakata Seed Sudamerica Ltda. (SDA)
Cucurbita pepo L. · Field pumpkin
A L TOZER LTD
Cucumis sativus L. · Cucumber
RIJK ZWAAN ZAADTEELT EN ZAADHANDEL B.V.
Trifolium pratense L. · Red clover
Malopolska Hodowla Roslin Spolka z o.o.
Cucumis melo L. · Melon
ESASEM, I
Triticum aestivum L. · Bread wheat
Lietuvos agrarinių ir miškų mokslų centras
Cucumis melo L. · Melon
Enza Zaden Beheer B.V.
Triticum aestivum L. · Bread wheat
SELGEN A.S