Introduction The cause of this leaf damage may occur in early spring when buds first start to open. The tender young leaves are very susceptible to freezing injury. Though the temperatures may warm up enough in March or April for winter dormancy to be broken and buds to begin to open, many parts of New York are subject to frosts well into May. This means that the tiny developing leaves can easily be frost-injured. Sometimes the injury is severe enough to kill all the leaves in early-opening buds, but often only small pockets of cells here and there on the tiny young leaves are killed. This more subtle frost injury is not noticed on the leaves until they are fully expanded. Then the frost killed areas appear as prominent holes because they did not keep pace with the rest of the leaf tissue as the young leaves expanded to full size. This uneven growth also frequently contributes to a distorted appearance of the injured leaves as well as the characteristic tatter.
Though alarming in appearance, this
injury does not usually seriously harm the tree. As the season progresses,
many leaves will be produced on the new growing shoots and the older
tattered leaves will make up a smaller proportion of the total amount
of foliage. At the same time, many of the badly tattered leaves
will drop off early. As a result, the leaf tatter will not appear
as serious and the plant will be less dependent on injured leaves
for its survival.
Control Strategies A vigorous tree or shrub should be able to survive this type of injury easily, unless it is repeated several years in succession or some other adverse factor weakens the tree in addition to the frost injury. Sugar maples showing leaf tatter symptoms may be suffering from injury by the pear thrips (Taeniothrips inconsequens Uzel). Further information on this pest is contained in the Diagnostic Laboratory fact sheet "Sugar Maple and the Pear Thrips" by Carl E. Palm. Updated, KLS, 1/00 This publication contains pesticide recommendations.
Changes in pesticide regulations occur constantly, some
materials mentioned may no longer be available, and some
uses may no longer be legal. All pesticides distributed,
sold, and/or applied in New York State must be registered
with the New York State Department of Environmental
Conservation (DEC). Questions concerning the legality and/or
registration status for pesticide use in New York State
should be directed to the appropriate Cornell Cooperative
Extension Specialist or your regional DEC office. READ
THE LABEL BEFORE APPLYING ANY PESTICIDE.
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