Sunjiraore
ActiveBegonia x tuberhybrida Voss · Tuberous begonia
Yamaguchi Hideki
Diseases
Leaf spot 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.
Breakdown by crop
Rose leaf spots
789
Tomato Leaf Spots
563
Barley Leaf Spot Diseases
541
Pepper Leaf Spots
277
Cucumber leaf spots
244
Leaf blotch — soft wheat
239
Leaf spots — Perennial ryegrass
181
Leaf spots — garden strawberry
141
Bean leaf spots
139
Leaf spots — tall fescue
125
Potato early blight
123
Peach Leaf Spots
120
Leaf spots of summer squash
107
Leaf Spot — Kentucky Bluegrass
105
Apple Leaf Spot
95
Maize leaf spots
82
Melon Leaf Spot
74
Olive leaf spot
71
Leaf spots — Creeping bentgrass
53
Carrot leaf blights
48
Leaf spots of red fescue
43
Maize leaf spots
35
Plum leaf spots
34
Triticale leaf spots
32
Found in these crops
Varieties that feature this in their description
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.
Tesseract
ActiveLavandula x intermedia Emeric ex Loisel. · Lavandin
Traven Lloyd R. / Grazzini Richard
Sophia
ActiveCoreopsis L. · Tickseed
Probst Darrell R
Smena
ActiveRibes uva-crispa L. · Gooseberry
VSEROSSIJSKIJ SELEKCZIONNO-TEXNOLOGICHESKIJ INSTITUT SADOVODSTVA I PITOMNIKOVODSTVA
SAKZIN017
ActiveZinnia x marylandica D. M. Spooner et al.
Sakata Seed Corporation (SCC)
Silver Ball
ActivePittosporum tenuifolium Gaertn. · Kohuhu
Mark Fyfe^^^Rachelle Fyfe
SAKZIN022
ActiveZinnia x marylandica D. M. Spooner et al.
SHINJI MINEMURA
Rhythm and Blues
ActiveAstilbe Buch.-Ham. ex D. Don · False goat's beard
Verduin Harry G. J.|Heemskerk, NL
SAKZIN021
ActiveZinnia x marylandica D. M. Spooner et al.
Sakata Seed Corporation
Profusion Apricot
ActiveZinnia L. · Zinnia
Sakata Seed Corporation (SCC)
PH8DB
ActiveZea mays L. · Maize
PIONEER HI-BRED INTERNATIONAL
R400MR
ActiveZea mays L. · Maize
CROOKHAM COMPANY
Phhb4
ActiveZea mays L. · Maize
PIONEER HI-BRED INTERNATIONAL
PH21T
ActiveZea mays L. · Maize
PIONEER HI-BRED INTERNATIONAL
Ph14t
ActiveZea mays L. · Maize
PIONEER HI-BRED INTERNATIONAL
PH6WA
ActiveZea mays L. · Maize
PIONEER HI-BRED INTERNATIONAL
Ph44a
ActiveZea mays L. · Maize
PIONEER HI-BRED INTERNATIONAL
PIILAG B1
ActiveLagerstroemia L. · Crape Myrtle
Kardos Joshua H.
Patriot Cranberry Red
ActivePelargonium zonale (L.) L'Hér. · Horseshoe pelargonium
OGLEVEE LTD
PHCA5
ActiveZea mays L. · Maize
PIONEER HI-BRED INTERNATIONAL
PH705
ActiveZea mays L. · Maize
PIONEER HI-BRED INTERNATIONAL
Mocha
ActiveHeuchera L. · Coral Flower
Sandrine Delabroye
Pachafapri
ActivePelargonium peltatum (L.) L'Hér. · Ivy-leaf geranium
Martin Geibel c/o Elsner pac Jungpflanzen GbR
Monnieves
ActiveIlex x meserveae S. Y. Hu · Meserve holly
Nieves García