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.
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.
Prunus persica (L.) Batsch · Peach
Grand Merrill (dcd) Mme Lucille Merrill (US)
Dianthus L. · Carnation
Nobbio G.
Cucumis sativus L. · Cucumber
Syngenta Seeds B.V.
Beta vulgaris Sugar Beet Group · Sugar beet
DLF Beet Seed APS
Daucus carota L. · Carrot
Vilmorin & Cie
Brassica oleracea L. (White Cabbage Group) · White cabbage
Instytut Ogrodnictwa - Państwowy Instytut Badawczy
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Marian Lisowski
Cucumis sativus L. · Cucumber
PLANTICO HODOWLA I NASIENNICTWO OGRODNICZE ZIELONKI SP. Z O.O.
Lolium perenne L. · Perennial ryegrass
DEUTSCHE SAAT| Deutsche Saatveredelung AG
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Instytut Ogrodnictwa - Państwowy Instytut Badawczy
Beta vulgaris Sugar Beet Group · Sugar beet
DLF Beet Seed APS
Triticum durum Desf. · Durum wheat
Saatzucht Donau GmbH & Co.KG
Solanum lycopersicum L. · Tomato
HM.Clause S.A.S.
Pyrus communis L. · European pear
Solanum lycopersicum L. · Tomato
Vilmorin SA (FR)
Beta vulgaris Sugar Beet Group · Sugar beet
KUTNOWSKA HODOWLA BURAKA CUKROWEGO Sp.z o.o.
Olea europaea L. · Olive
Petroselinum crispum (Mill.) Nyman ex A. W. Hill · Parsley
Nunhems Germany GmbH
Lolium perenne L. · Perennial ryegrass
AGRIBIOTECH INC.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Leis Michelangelo, Martinelli Alessio
Cucumis sativus L. · Cucumber
SUNSEEDS
Hordeum vulgare L. · Barley
Limagrain Europe S.A.S
Ribes rubrum L. · Redcurrant
Maa- ja elintarviketaouden tutkimuskeskus (MTT)/ Present Luonnonvarakeskus (Luke))
Cucumis sativus L. · Cucumber
SEMILLAS FITO, S.A.