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.
Hordeum vulgare L. · Barley
Saatzucht Donau Ges.m.b.H. & CoKG (AT)
Poa pratensis L. · Kentucky bluegrass
Loft's Seed Inc. (US)
Poa pratensis L. · Kentucky bluegrass
Pennington Seeds Inc
Solanum lycopersicum L. · Tomato
Seminis Vegetable Seeds
Solanum lycopersicum L. · Tomato
Syngenta Seeds B.V.
Solanum lycopersicum L. · Tomato
Harris Moran Seed Company (USA) (US)
Vicia faba L. var. minuta (hort. ex Alef.) Mansf. · Tick Bean
Selgen a.s., CZ
Helianthus annuus L. · Sunflower
prof.Nina Nenova
Cucumis sativus L. · Cucumber
SEMILLAS FITO, S.A.
Beta vulgaris Fodder Beet Group · Mangelwurzel
Malopolska Hodowla Roslin Spolka z o.o.
Spinacia oleracea L. · Spinach
Enza Zaden Beheer B.V.
Prunus persica (L.) Batsch · Peach
N'guyen Din Mao (FR)
Lolium multiflorum Lam. ssp. italicum (A. Br.) Volkart · Italian ryegrass
EIGEN VERMOGEN VH INSTITUUT VOOR LANDBOUW- EN VISSERIJONDERZOEK
Zea mays L. · Maize
BAYERISCHE PFLANZENZUCHTGESELLSCHAFT EG & CO
Cucumis sativus L. · Cucumber
Syngenta Crop Protection AG
Solanum lycopersicum L. · Tomato
Bakker Brothers Gebroeders Bakker Zaadteelt en Zaadhandel BV
Ilex L. · Holly
Meserve, Kathleen K.|St. James, NY
Solanum lycopersicum L. · Tomato
Torsten Olsson Frö AB
Beta vulgaris Sugar Beet Group · Sugar beet
KUTNOWSKA HODOWLA BURAKA CUKROWEGO Sp.z o.o.
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Beta vulgaris Fodder Beet Group · Mangelwurzel
Malopolska Hodowla Roslin Spolka z o.o.
Solanum lycopersicum L. · Tomato
Enza Zaden Beheer B.V.
Beta vulgaris Sugar Beet Group · Sugar beet
KWS SAAT SE & CO.KGAA
Rosa L. · Rose
Meilland, Alain A.|Antibes, France