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.
Avena sativa L. · Oat
EBMEYER| KWS LOCHOW GMBH Herrn Dr. Erhard Ebmeyer
Solanum lycopersicum L. · Tomato
Johnny's Selected Seeds
Solanum lycopersicum L. · Tomato
Vilmorin-Mikado S.A.S.
Solanum lycopersicum L. · Tomato
HM Clause Inc (US)
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Instytut Ogrodnictwa - Państwowy Instytut Badawczy
Allium porrum L. · Leek
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Spinacia oleracea L. · Spinach
Enza Zaden Beheer B.V.
Olea europaea L. · Olive
Brassica napus var. napus · Rapeseed
Hodowla Roslin Strzelce Sp z.o.o. Grupa IHAR
Solanum lycopersicum L. · Tomato
UNITED GENETICS SEEDS CO
Lactuca sativa L. · Lettuce
Enza Zaden Beheer B.V.
Beta vulgaris Garden Beet Group · Garden beet
SPÓJNIA Hodowla i Nasiennictwo Ogrodnicze sp. z o.o.
Avena nuda L. · Naked oat
Lietuvos agrarinių ir miškų mokslų centras
Solanum lycopersicum L. · Tomato
HAZERA SEEDS BV
Beta vulgaris Sugar Beet Group · Sugar beet
Breeding Division of Hellenic Sugar Industry
Medicago sativa L. · Alfalfa
NORTHRUP KING Co (US)
Brassica napus L. · Rapeseed
NORDDEUTSCHE PFLANZENZUCHT LUBECK
Beta vulgaris Sugar Beet Group · Sugar beet
KUTNOWSKA HODOWLA BURAKA CUKROWEGO Sp.z o.o.
Hordeum vulgare L. · Barley
PER LUNDIN C/O SVALÖF WEIBULL AB
Solanum lycopersicum L. · Tomato
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Phaseolus vulgaris L. · Common bean
Monsanto Vegetable IP Management B.V.
Beta vulgaris Sugar Beet Group · Sugar beet
DLF Beet Seed APS
Cucumis sativus L. · Cucumber
PLANTICO HODOWLA I NASIENNICTWO OGRODNICZE ZIELONKI SP. Z O.O.
Lolium perenne L. · Perennial ryegrass
NexGen Plant Science center LLC