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.
Zea mays L. subsp. mays (Maize Group) · Maize
Hodowla Roslin Smolice Sp.z o.o Grupa IHAR
Brassica oleracea L. (Cauliflower Group) · Cauliflower
TAKII & CO LTD
Cichorium intybus L. (Industrial Chicory Group) · Chicory
ILVO Plant/Chicoline a division of Cosucra Groupe Warcoing
Hordeum vulgare L. · Barley
Syngenta Crop Protection AG, CH
Hordeum vulgare L. · Barley
Löhde Jörgen
Beta vulgaris Sugar Beet Group · Sugar beet
Syngenta Seeds
Beta vulgaris Sugar Beet Group · Sugar beet
KWS SAAT SE & CO.KGAA
Hordeum vulgare L. · Barley
Graminor A.S
Solanum lycopersicum L. · Tomato
DE RUITER SEEDS
Beta vulgaris Sugar Beet Group · Sugar beet
Dietrich Hauer, Madlaina Peter,
Beta vulgaris Sugar Beet Group · Sugar beet
KWS SAAT SE & CO.KGAA
Spinacia oleracea L. · Spinach
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Beta vulgaris Sugar Beet Group · Sugar beet
SUGAR BEET RESEARCH INSTITUTE
Triticum aestivum L. · Bread wheat
RAGT CZECH S.R.O.
Beta vulgaris Sugar Beet Group · Sugar beet
SESVANDERHAVE, N.V./S.A.
Solanum lycopersicum L. · Tomato
Clause Semences SA (FR)
Zea mays L. subsp. mays (Maize Group) · Maize
KWS SAAT SE & CO.KGAA
Beta vulgaris Sugar Beet Group · Sugar beet
D.J.VAN DER HAVE
Brassica napus var. napus · Rapeseed
M A Pickford
Lolium perenne L. · Perennial ryegrass
VIRGINIA LEHMAN/LOFT'S
Zea mays L. · Maize
PIONEER OVERSEAS CORPORATION
Zea mays L. · Maize
PIONEER HI-BRED INTERNATIONAL
Solanum lycopersicum L. · Tomato
Sakata Seed Sudamerica Ltd (BR)
Beta vulgaris Sugar Beet Group · Sugar beet
Syngenta Crop Protection AG, CH