4. Symptoms
ď‚—
Pseudomonas syringae
ď‚— Symptoms
ď‚— Small black, angular spots in leaves; large brown
spots on leaves, flowers and/or fruits
ď‚— Cause
ď‚— Bacteria
ď‚— Comments
ď‚— Disease emergence favored by poor air
circulation around branches and wet foliage
ď‚— Management
ď‚— Branches exhibiting dieback and severe blighting
should be pruned out of the canopy; avoid
overhead irrigation; if cankers appear on the
trunk of the tree then it is likely it will die and it
should be removed
ď‚—
Bacterial blight—Pseudomonas syringae
5. Symptoms
ď‚— A canker is a sunken area
containing dead tissue on a
stem or branch. It may not
be clearly visible, or it may
be a well-defined infection
on woody parts that often
becomes surrounded by
layers of callus tissue.
Cankers can cause foliage
on infected branches to
turn yellow or brown and
wilt. Infected bark often
discolors
Canker Disease
6. ď‚— Popcorn Disease (fungus
– Ciboria carunculoides):
This disease, known only in
the southern states, is
largely confined to the
carpels of the fruit. It
causes them to swell and
remain greenish, and
interferes with ripening.
The disease is of little
importance. It does not
lessen the value of the tree
as an ornamental.
Popcorn Disease
7. Symptoms
Several fungal diseases,
sometimes called heart or
sap rots, cause the wood in
the center of trunks and
limbs to decay. Under
conditions favoring growth
of certain rot fungi,
extensive portions of the
wood of living trees can
decay in a relatively short
time (i.e., months to years).
Wood Decay Fungi