KWS Creswell
ActiveHordeum vulgare L. · Barley
KWS UK LTD
Diseases
Leaf spot diseases
Leaf spot diseases are a group of fungal, bacterial, or viral disorders manifesting as tissue necrosis in the form of spots of various shapes and colors. Pathogen development leads to a reduction in photosynthetic leaf area, tissue deformation, and significant yield losses.
Mentioned in descriptions 15 926 varieties reference book.
Leaf spot diseases represent a collective group of conditions caused by fungi, bacteria, or viruses. The primary diagnostic symptom is the formation of spots of various colors—brown, yellow, black, or gray—on the leaf blades, ranging from small dots to extensive necrotic lesions with or without margins. Infection often originates in the lower leaf canopy and, if allowed to develop, leads to premature defoliation and overall plant weakening.
Disease progression depends on a combination of favorable meteorological factors, such as moderately warm temperatures and high humidity, as well as the agrotechnical background. Improper crop rotation and the retention of crop residues in fields contribute to the accumulation of inoculum and intensive infection of crops in subsequent seasons. The severity of disease manifestation correlates directly with pathogen aggressiveness and the degree of cultivar susceptibility, which can lead to a 20–30% or greater reduction in crop productivity.
Cultivar resistance to leaf spots is a genetically determined ability to maintain productivity under disease pressure. It can be specific, targeting particular pathogen races, or non-specific polygenic, providing complex protection. Resistance mechanisms include physical barriers, such as waxy coatings, and biochemical responses. During variety testing, resistance is evaluated under natural and artificial inoculation conditions using scoring scales to record the degree of necrosis and pathogen development.
Breakdown by crop
Rose leaf spots
789
Tomato Leaf Spots
563
Barley Leaf Spot Diseases
541
Pepper Leaf Spots
277
Cucumber leaf spots
244
Leaf blotch — soft wheat
239
Leaf spots — Perennial ryegrass
181
Leaf spots — garden strawberry
141
Bean leaf spots
139
Leaf spots — tall fescue
125
Potato early blight
123
Peach Leaf Spots
120
Leaf spots of summer squash
107
Leaf Spot — Kentucky Bluegrass
105
Apple Leaf Spot
95
Maize leaf spots
82
Melon Leaf Spot
74
Olive leaf spot
71
Leaf spots — Creeping bentgrass
53
Carrot leaf blights
48
Leaf spots of red fescue
43
Maize leaf spots
35
Plum leaf spots
34
Triticale leaf spots
32
Found in these crops
Varieties that feature this in their description
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.
Lanconnecticut
ActiveMandevilla sanderi (Hemsl.) Woodson · Brazilian jasmine
Lannes Robert
Jonsok
ActiveFragaria x ananassa Duchesne ex Rozier · Garden strawberry
NHL, Ås, Norway
Jm1
Application submittedMalus domestica (Suckow) Borkh. · Apple
YOSHIO YOSHIDA^^^SHICHIRO TSUCHIYA^^^Jun-ichi Soejima
Jm7
ActiveMalus domestica (Suckow) Borkh. · Apple
YOSHIO YOSHIDA^^^SHICHIRO TSUCHIYA^^^Jun-ichi Soejima
Imola
TerminatedBrassica napus var. napus · Rapeseed
KWS UK LTD
Jonica
ActiveFragaria x ananassa Duchesne ex Rozier · Garden strawberry
Walther Faedi^^^Gianluca Baruzzi^^^Pierluigi Lucchi^^^Paolo Sbrighi
JHE00113
ActiveHelleborus x hybridus hort. ex Voss · Lenten rose
Floréac N.V.
Heartbreaker
ActiveVeronica L. · Speedwell
JOH. VAN NIEKERK
G15270
ActiveGaillardia Foug. · Blanket flower
Richard A. Grazzini
Gold Nugget
Application submittedVerbascum L. · Mullein
Korlipara Harini|Canby, OR, US
Gold Dust
ActivePhaseolus vulgaris L. · Common bean
Seminis Vegetable Seeds
EP ACEPA
ActiveAcer platanoides L. · Norway maple
Tomas Lagerström
Ember Glow
ActiveKniphofia Moench · Red hot poker
Janet N. Egger
Filigree Lace
ActiveBetula pendula Roth · Silver birch
TERRA NOVA NURSERIES INC
Green Envy
ActiveEchinacea purpurea (L.) Moench · Purple coneflower
Mark Veeder
Green Eyes
ActiveEchinacea purpurea (L.) Moench · Purple coneflower
Korlipara Harini|Canby, OR, US
Fancy Frills
ActiveEchinacea purpurea (L.) Moench · Purple coneflower
Korlipara Harini|Canby, OR, US
Delgas
ActivePopulus deltoides W. Bartram ex Marshall · Eastern cottonwood
Institut National de Recherche pour l'Agriculture l'Alimentation et l'Environnement (INRAE) , Institut National de Recherche en Sciences et Technologies pour l’Environnement et l’Agriculture (IRSTEA), Institut Technologique FCBA
Dark Star
ActiveFittonia albivenis (Lindl. ex hort. Veitch) Brummitt · Nerve plant
Schoenmakers Tropische Potcultures V.O.F.
Florencia
Application submittedFragaria x ananassa Duchesne ex Rozier · Garden strawberry
Flevo Berry Holding B.V.
Creamsicle
ActiveKniphofia Moench · Red hot poker
Janet N. Egger
Elgar
ActiveBrassica napus var. napus · Rapeseed
SYNGENTA WINTER OILSEED AB
Cantona
TerminatedFestuca ovina L. · Sheep's fescue
DLF Seeds A/S