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.
Cucumis sativus L. · Cucumber
SEMO a.s
Hordeum vulgare L. · Barley
Graminor AS, N-2322 Ridabu
Trifolium pratense L. · Red clover
SELGEN A.S
Lolium perenne L. · Perennial ryegrass
DLF Seeds A-S, DK
Lolium perenne L. · Perennial ryegrass
BARENBRUG UK LTD
Solanum lycopersicum L. · Tomato
Syngenta, NL
Hordeum vulgare L. · Barley
Nickerson International Research S.N.C.
Hordeum vulgare L. · Barley
Syngenta UK Ltd
Dactylis glomerata L. · Cocksfoot
FAL Station de Recherche Agronomique Federale (CH)
Hordeum vulgare L. · Barley
VASILESCU LILIANABUDE ALEXANDRUPOPESCU CONSTANTA
Daucus carota L. · Carrot
Jonh Pieter Schipper
Helianthus annuus L. · Sunflower
RAGT 2N S.A.S
Beta vulgaris Sugar Beet Group · Sugar beet
SAS FLORIMOND-DESPREZ Veuve et Fils
Hordeum vulgare L. · Barley
SAATZUCHT JOSEF BREUN GmbH&Co.KG
Lupinus luteus L. · Yellow lupin
WESTERN AUSTRALIAN DEPARTMENT OF
Oryza sativa L. · Rice
LUGANO LEONARDO SRL
Festuca arundinacea Schreb. · Tall fescue
PURE SEED TESTING
Poa pratensis L. · Kentucky bluegrass
Pickseed West Inc (US)
Cucumis sativus L. · Cucumber
Nunhems, B.V.
Festuca arundinacea Schreb. · Tall fescue
PURE SEED TESTING
Festuca arundinacea Schreb. · Tall fescue
Rutgers, the State University of New Jersey and Novel AG, Inc.
Daucus carota L. · Carrot
Vilmorin, F
Hordeum vulgare L. · Barley
Syngenta UK Ltd
Festuca arundinacea Schreb. · Tall fescue
Z Seeds, LLC and Rutgers, The State University of New Jersey