Kisarlav
ActiveImpatiens New Guinea Group · New Guinea Impatiens
Ludwig Kientzler
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.
Impatiens New Guinea Group · New Guinea Impatiens
Ludwig Kientzler
Humulus lupulus L. · Common hop
Anton Lutz
Ocimum basilicum L. · Basil
Nunhems Germany GmbH
Humulus lupulus L. · Common hop
Peter Darby
Impatiens walleriana Hook. f. · Busy Lizzie
Syngenta Seeds B.V.
Humulus lupulus L. · Common hop
Herbert Ehrmaier
Phlox paniculata L. · Garden phlox
Tonies Hubertus Josephus|Noordwijkerhout, NL
Rosa L. · Rose
CHRISTIAN BEDARD
Vitis L. · Grapevine
ALIEV ARIF MUZAFAROVICh / KOSTRIKIN IVAN ALEKSANDROVICh / IVANOV JORDAN / VYLChEV VASIL / MUZYChENKO BORIS ALEKSANDROVICh
Vitis vinifera L. · Common grape vine
Marco Stefanini Fondazione Edmund Mach (FEM-CRI)
Ocimum basilicum L. · Basil
James E. Simon, Robert Michael Pyne, Christian Andrew Wyenandt, Rutgers, The state university of New Jersey
Vitis vinifera L. · Common grape vine
Simone Diego Castellarin^^^Guido Cipriani^^^Gabriele Di Gaspero^^^Michele Morgante^^^Enrico Peterlunger^^^Raffaele Testolin
Vitis L. · Grapevine
Valentin Blattner
Vitis L. · Grapevine
Norbert Becker
Ocimum basilicum L. · Basil
Nunhems Germany GmbH
Humulus lupulus L. · Common hop
Peter Darby
Vitis L. · Grapevine
Valentin Blattner
Lactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
Brassica oleracea L. (Broccoli Group) · Broccoli
FARRARA BARRY
Erysimum linifolium (Pers.) J. Gay · Wallflower
Trees Scott C
Impatiens walleriana Hook. f. · Busy Lizzie
SIMONE E. CRAIN
Impatiens walleriana Hook. f. · Busy Lizzie
SIMONE E. CRAIN
Vitis vinifera L. · Common grape vine
Bundesrepublik Deutschland vertreten durch Julius Kühn-Institut, Institut National de Recherche pour l'Agriculture l'Alimentation et l'Environnement (INRAE)
Diplotaxis tenuifolia (L.) DC. · Perennial wall-rocket
Enza Zaden Beheer B.V.