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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.

Sources10

Breakdown by crop

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.

Rhododendron L. · Azalea

BOOMTEELTPRAKTIJKONDERZOEK

2 records

Geranium maculatum L. · Spotted geranium

Tyssowski Carol / Tyssowski Carol

2 records

Helleborus x ericsmithii

Josef Heuger

2 records

Binar

Active

Ribes nigrum L. · Blackcurrant

VOLODINA YEKATARINA V.^^^KHOTIMSKAYA SVETLANA P.^^^TIKHONOVA OLGA A.

5 records

Ditosnow

Active

Phlox paniculata L. · Garden phlox

Ditoplant Export B.V.

2 records

Echinacea Moench. · Coneflower

Ren Jianping

2 records

Beniminori

Application submitted

Malus domestica (Suckow) Borkh. · Apple

National Agriculture and Food Research Organization (NARO)

3 records

Hibiscus coccineus x Hibiscus moscheutos L.

Zwetzig Gretchen

2 records

Vitex agnus-castus L. · Chaste tree

Roberts David Jonathan,Schulze Justin,McBee Oren

2 records

Lagerstroemia L. · Crape Myrtle

Michael A. Dirr^^^Rhonda Helvick^^^Joshua H. Kardos^^^Oren McBee

2 records

Bik C3

Protection expired

Beta vulgaris Garden Beet Group · Garden beet

Bejo Zaden B.V.

2 records

Casino

Active

Papaver orientale L. · Oriental poppy

Peek Eleonore|Oudelande, NL

3 records

Hybrids between Echinacea purpurea (L.) Moench and Echinacea paradoxa (Norton) Britton

HARINI KORLIPARA

2 records

Ribes nigrum L. · Blackcurrant

SCOTTISH CROP RESEARCH INSTITUTE

3 records

Cameo

Active

Magnolia L. · Magnolia

Vance Hooper

2 records

Campanula punctata Lam. · Spotted bellflower

TERRA NOVA NURSERIES INC

2 records

Big Ben

Active

Ribes nigrum L. · Blackcurrant

SCOTTISH CROP RESEARCH INSTITUTE

4 records

Andes

Terminated

Lolium perenne L. · Perennial ryegrass

MOMMERSTEEG INTERNATIONAL

3 records

Annys1

Active

Ilex crenata Thunb. · Japanese holly

van Nijnatten Andre Franciscus

2 records

Echinacea purpurea (L.) Moench · Purple coneflower

IT Saul Plants LLC

2 records

Hybrids between Echinacea purpurea (L.) Moench and Echinacea paradoxa (Norton) Britton

Saul Robert|Atlanta, GA, US

2 records

Concorde

Protection expired

Zea mays L. subsp. mays (Maize Group) · Maize

Coop de Pau SCA (FR)

ES FR
3 records

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