Symptoms and damage
On maple (Acer species)
trees a number of problems cause symptoms that are generally classified as leaf
scorch. Scorch symptoms are light brown or tan dead areas between leaf veins or
around the leaf margins. Occasionally the leaf margins are yellow or chlorotic.
Scorch symptoms tell us that one or more of the following factors are affecting
leaf scorch is the most common. It is caused by dry weather, combined with wind
and high temperatures. When trees do not get enough water they will scorch. The
symptoms are on all parts of the tree or only on the side exposed to sun and
wind. Scorching due to dry soil may be overcome by proper watering.
response to an undesirable soil contaminant, such as salt (applied to roads for
wintertime ice control), accumulation of fluorides in containerized soil mixes
with perlite, or high levels of phosphate fertilizers.
reaction to a vascular pathogen, either fungal or bacterial.