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.
Helianthus annuus L. · Sunflower
N. Nenov, Y. Simeonova-Stoyanova, P. Shindrova, P. Petrov, V. Velkov, A. Piskov, D. Petakov, L. Nikolova, M. Hristov, V. Encheva, F. Tsvetkova, V. Venkov
Cucumis sativus L. · Cucumber
Dymchenko Tetiana Mykolaivna, Muzhylko Viktor Valentynovych,
Pisum sativum L. · Pea
Nunhems Zaden BV (NL)
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Lactuca sativa L. var. capitata L. · Head lettuce
PLANTICO HODOWLA I NASIENNICTWO OGRODNICZE ZIELONKI SP. Z O.O.
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Helianthus annuus L. · Sunflower
Mehmet Ali Keceli
Vitis L. · Grapevine
Bakonyi Karoly / Bakonyi Laszlo / Kocsis Laszlo
Vitis L. · Grapevine
Institut National de la Recherche Agronomique (FR)/Bureau National Interprofessionnel du Cognac (FR)
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Humulus lupulus L. · Common hop
Instytut Uprawy Nawożenia i Gleboznawstwa Państwowy Instytut Badawczy
Humulus lupulus L. · Common hop
Instytut Uprawy Nawożenia i Gleboznawstwa Państwowy Instytut Badawczy
Citrullus lanatus (Thunb.) Matsum. & Nakai · Watermelon
ZETA SEEDS S.L.
Lactuca sativa L. var. crispa L. · Leaf lettuce
Mytenko Inna Mykolaivna, Kuraksa Nina Petrivna, Nesyn Volodymyr Mykolaiovych, Pozniak Oleksandr Vasyl`ovych, Tkalych IUrii Vadymovych, Korniienko Serhii Ivanovych, Horova Tamara Korniivna, Kondratenko Serhii Ivanovych,
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Lactuca sativa L. · Lettuce
ReinSaat KG
Cucumis sativus L. · Cucumber
Krylov Oleh Mykolaiovych, Borysov Oleksandr Volodymyrovych,
Vitis L. · Grapevine
INCONNU (FR)
Lactuca sativa L. · Lettuce
MARALDI SEMENTI S.r.l.
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Vitis vinifera L. · Common grape vine
Stasieva Mariia Ivanivna, Yarmak IEvheniia Dmytrivna, Storozhuk Kateryna Moisiivna, Bankovska Mariia Hryhorivna, Dylyk Antonina Petrivna, Dokuchaieva IEvheniia Mykolaivna, Meleshko Larysa Fedorivna,
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Allium cepa L. · Onion
Ger Bimsdeboer
Vitis L. · Grapevine
INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE, FR