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
LEMAIRE DEFFONTAINES S.A.S.
Hordeum vulgare L. · Barley
SAATZUCHT JOSEF BREUN GmbH&Co.KG
Brassica napus var. napus · Rapeseed
LIMAGRAIN EUROPE
Cucumis sativus L. · Cucumber
BEJO ZADEN B.V, NL
Hordeum vulgare L. · Barley
SEJET PLANTEFORÆDLING
Hordeum vulgare L. · Barley
ERHARDT EGER
Spinacia oleracea L. · Spinach
Syngenta Crop Protection AG
Alstroemeria L. · Alstroemeria
van Zanten Plants b.v
Hordeum vulgare L. · Barley
Graminor AS, N-2322 Ridabu
Lolium perenne L. · Perennial ryegrass
DLF Seeds A/S
Triticum aestivum L. · Bread wheat
Wiersum Plantbreeding B.V.
Phaseolus vulgaris L. · Common bean
Pop Vriend Research B.V.
Hordeum vulgare L. · Barley
SAATZUCHT JOSEF BREUN GmbH&Co.KG
Phaseolus vulgaris L. · Common bean
Vilmorin SA (FR)
Festuca rubra L. · Red fescue
Pickseed Canada Inc., Ontario, K9V 4S3
Festuca arundinacea Schreb. · Tall fescue
Jouffray-Drillaud SA (FR)
Hordeum vulgare L. · Barley
Graminor AS, N-2322 Ridabu
Festuca arundinacea Schreb. · Tall fescue
DLF Pickseed USA
Phaseolus vulgaris L. · Common bean
Monsanto Vegetable IP Management B.V.
Hordeum vulgare L. · Barley
Graminor AS, N-2322 Ridabu
Hordeum vulgare L. · Barley
Syngenta Participations AG
Oryza sativa L. · Rice
Almo S.p.A.
Festuca arundinacea Schreb. · Tall fescue
Peak Plant Genetics, LLC & Rutgers, The State University of New Jersey
Festuca arundinacea Schreb. · Tall fescue
Rutgers, The State University of New Jersey