Diseases
Peronosporaceae
Downy mildew is a dangerous plant disease caused by oomycetes under high humidity conditions. It manifests as a characteristic growth on the underside of leaves and spotting, which leads to rapid death of vegetative mass and yield reduction.
Mentioned in descriptions 16 384 varieties reference book.
Downy mildew is a group of diseases caused by specialized oomycetes. The disease manifests as the appearance of yellowish or brown angular spots on the upper side of the leaves, delimited by veins. On the underside of the leaf, under humid conditions, a characteristic grey-violet, white, or bluish fuzzy growth forms. Pathogen development leads to yellowing and drying of leaves, stunting of plants, and deformation of fruits, which, in the case of high pathogen aggressiveness, can lead to crop death in a short period.
Disease development depends directly on meteorological conditions and agronomic practices. The pathogen prefers a cool, humid environment, with critical risk factors being heavy dew, fog, prolonged rain, high air humidity, and crop density. Optimal conditions for infection include nighttime temperatures in the range of +13…+20°C and the presence of droplet moisture on the leaf surface for more than 6 hours.
Assessment of variety resistance during variety testing is based on phytopathological recording of the degree of leaf damage, specialized screening of collection samples, and molecular analysis methods using DNA markers to find genetic donors of resistance. In production, a distinction is made between genetically resistant varieties possessing specific Dm-genes and tolerant forms capable of maintaining yield under infection due to active vegetative mass formation. Since new pathogen races can overcome genetic resistance, varieties require regular monitoring and renewal.
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 sativus L. · Cucumber
Yost van den Eiden
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Helianthus annuus L. · Sunflower
David Mogford
Cucumis sativus L. · Cucumber
Lim Sang Hwa
Helianthus annuus L. · Sunflower
Stots`kyi Viktor Pavlovych
Helianthus annuus L. · Sunflower
APSOVSEMENTI S.P.A.
Lactuca sativa L. · Lettuce
RIJK ZWAAN Z.Z. B.V.
Brassica napus L. · Rapeseed
KOIPESOL S.A.
Vicia narbonensis L. · French vetch
SEMILLAS BATLLE, S.A.
Helianthus annuus L. · Sunflower
Burlov Viktor Vasylovych
Pisum sativum L. · Pea
Bortnovskyi Vitalii Mykolaiovych, Kondratenko Mykola Ivanovych, Buhaiov Vasyl Dmytrovych,
Cucumis melo L. · Melon
Ersyn Hiunes
Cucumis sativus L. · Cucumber
Bartkovska Zofiia, Drozhdzhevska Krystyna, Lakovska-Ryk El`zhbeta, Dorukhovski Rokh,
Impatiens New Guinea Group · New Guinea Impatiens
Kientzler Ludwig
Helianthus annuus L. · Sunflower
Berestenko Serhii Leonidovych, Scherban` Serhii Vasyl`ovych, Scherban` Natalia Fedorivna,
Lactuca sativa L. var. capitata L. · Head lettuce
CORA SEEDS S.R.L
Vitis vinifera L. · Common grape vine
ISPAS SOFIAGRESOI VIRGIL
Allium cepa L. · Onion
Ger Bimsdeboer
Vitis vinifera L. · Common grape vine
Hochschule Geisenheim University Institut für Pflanzenzüchtung Herrn Prof. Dr. Ernst Rühl
Vitis vinifera L. · Common grape vine
Dr. Helmut Schleip (+) in Staatliche Lehr- und Versuchs- anstalt für Wein- und Obstbau
Lactuca sativa L. · Lettuce
RIJK ZWAAN Z.Z. B.V.
Fagopyrum esculentum Moench · Buckwheat
Shevel` Vitalii Ihorevych, Shevel` Ihor Vasyl`ovych, Dykyi Viktor Vasyl`ovych,
Lactuca sativa L. · Lettuce
RIJK ZWAAN Z.Z. B.V.
Vitis L. · Grapevine
INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE, FR