Disease name: Beech leaf disease
Pathogen name: Litylenchus crenatae mccannii (nematode)
Hosts: Native and ornamental beech species are susceptible. These include American beech (Fagus grandifolia), European beech (F. sylvatica), and Oriental beech (F. orientalis).
Beech leaf disease was first observed in 2012 in Lake County, Ohio. It has since been seen in Pennsylvania, Connecticut, New York, and Ontario, Canada.
This disease is capable of killing young and old trees within six years of symptom development.
This disease is not well understood at this time, but there is ongoing research.
Symptoms
The foliar symptoms of beech leaf disease are often first noticed on leaves on lower branches. The symptoms are a dark green discoloration and a thickening of leaf tissue between the infected veins. This creates a striped or banded appearance. These symptoms are seen shortly after spring leaves emerge and harden-off. Leaves may also appear crinkled, distorted, and small in size.
As the infection progresses, the leaves may appear entirely darkened before they develop chlorosis or yellowing in between the veins. As more leaves and buds become infected, the canopy will begin to thin. This leads to decline and death of the tree.
Disease Cycle
The nematode that causes beech leaf disease, Litylenchus crenatae mccannii, overwinters in buds and infected detached leaves.
Infection can occur in the early spring as leaves emerge from the buds.
All life stages of the nematodes occur within the leaf blade.
The population is the highest in the autumn.
Management
Cultural Management
Preventing introductions and spread of beech leaf disease are the best ways to manage this disease at this time.
Early reporting of symptoms consistent with beech leaf disease can aid in preventing spread.
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For current pesticide recommendations, contact The Morton Arboretum Plant Clinic at 630-719-2424 or plantclinic@mortonarb.org.