DiseaseMedium Severity

Cephalosporium Ulmi (Dothiorella Ulmi)

Dothiorella ulmi (formerly Cephalosporium ulmi)

A vascular wilt disease affecting American elms, now classified as Dothiorella ulmi. This fungal pathogen causes wilting, yellowing, and dieback symptoms that resemble other wilt diseases. Stress factors significantly increase susceptibility to infection.

Peak Season: Spore release: Spring rainsPrimary infection: During wet spring weatherPycnidia development: Summer and autumnSecondary spread: Throughout growing seasonOptimal conditions: Wet weather with overhead irrigation
Elm vascular wilt symptoms

Identification & Symptoms

What to Look For

Foliage yellowing and wilting in scattered crown portions
Generalized wilt spreading throughout the tree
Gradual dieback of affected branches
Brown discoloration in outer wood rings
Elliptical cankers on stems
Small black specks (pycnidia) in infected areas
Sticky spore masses in wet weather

Potential Damage

Vascular system disruption from vessel plugging
Progressive crown decline and dieback
Canker development around infection sites
Potential tree mortality in severe cases
Structural weakness from repeated infections

Lifecycle

Spores are released during spring rains and spread by wind, rain, overhead irrigation, and pruning tools. Infection usually occurs through leaf wounds but may enter through stem wounds. The fungus moves down leaf petioles into twigs, plugging vessels and creating cankers.

Professional Treatment Approach

1

Fungisol applications for vascular disease management

2

Address stress factors: improve drainage, reduce compaction

3

Proper pruning practices to minimize wounds

4

Avoid overhead irrigation where possible

5

Nutritional support programs to maintain tree vigor

Recommended Mauget Products

Fungisol

Professional-grade treatment specifically effective against cephalosporium ulmi (dothiorella ulmi).

View Product Details

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