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.
Ficus carica L. · Common fig
JUNTA DE EXTREMADURA - FINCA LA ORDEN-VALDESEQUERA
Oryza sativa L. · Rice
RICE TEC INC.
Cucumis sativus L. · Cucumber
CAPITAL GENETIC EBT, S.L.
Citrus clementina hort. ex Tanaka · Clementine
Cucumis sativus L. · Cucumber
PlantiCo Hodowla i Nasiennictwo Ogrodnicze Golebiew sp. z o.o.
Solanum lycopersicum L. · Tomato
Vilmorin-Mikado S.A.S.
Solanum lycopersicum L. · Tomato
Enza Zaden Beheer B.V.
Solanum lycopersicum L. · Tomato
PETOSEED CO
Cydonia oblonga Mill. · Quince
INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE, FR
Fragaria L. · Strawberry
Voth, Victor|Santa Ana, CA / Bringhurst, Royce S.|Davis, CA
Apium graveolens L. var. dulce (Mill.) Pers. · Celery
PYBAS VEGETABLE SEED CO.
Spinacia oleracea L. · Spinach
Pop Vriend Research B.V.
Beta vulgaris Sugar Beet Group · Sugar beet
SESVANDERHAVE N.V./S.A.
Solanum lycopersicum L. · Tomato
HAZERA SEEDS BV
Beta vulgaris Sugar Beet Group · Sugar beet
SESVANDERHAVE, N.V./S.A.
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Beta vulgaris Sugar Beet Group · Sugar beet
KWS SAAT SE and CO KGAA
Solanum lycopersicum L. · Tomato
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Beta vulgaris Garden Beet Group · Garden beet
PLANTICO HODOWLA I NASIENNICTWO OGRODNICZE ZIELONKI SP. Z O.O.
Beta vulgaris Sugar Beet Group · Sugar beet
KUHN & Co Internacional B.V. (NL)
Beta vulgaris Sugar Beet Group · Sugar beet
DLF Beet Seed APS
Beta vulgaris Fodder Beet Group · Mangelwurzel
Malopolska Hodowla Roslin Spolka z o.o.
Poa pratensis L. · Kentucky bluegrass
O.M. SCOTT & SONS CO.
Daucus carota L. · Carrot
INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE, FR