American elm "chlorosis"
env_gln@SHSU.edu
Thu, 11 Sep 1997 15:15:48 -0500
In southeast Texas, American elms are having a tough
time.Early in the summer, the leaves begin to lose their
"green" andby this time (Aug-Sep),they can be spotted from
a long distance by the yellow brown color. The leaves stay
attached. Aphids sometimes are abundant on the leaves under-
neath, especially in the summer when there's plenty of green,
but many trees suffering from this malady don't have aphids.
Under a lens, the only chlorophyll remaining now is in fine
lines along the veins. There is no wilt or deformation of
the leaf shape or edges. No apparent correlation with
habitat. No report or knowledge of Dutch elm disease (?)
from this region. Winged elms also are common in the area
but don't have the same problem. Nor do Asian elms or hack-
berries. What's the problem with these trees? It's surprising
that they stay alive.
Guy Nesom
Sam Houston State University
Huntsville, Texas