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Sunday, August 26, 2012



Sunday, 7:30 AM.  70 degrees F, wind W, calm o very  light.  The sky is overcast, the humidity is 70% and it feels like rain, but the barometer predicts sunny weather.  I predict a few morning showers. We will see.
    Early turning of leaves can be a sign of drought, or of unseasonably warm weather, or it can be a sign of stress from disease or environmental pollutants such as, characteristically, road salt. Maples and conifers are particularly sensitive to salt, and can show damage just from drifted salt spray quite a ways downwind of a heavily traveled road.
    There is a sugar maple in Fountain Garden Park that has been in decline for several years.  Branches are dying from the top of the tree down, leaves turning red and falling throughout the summer.  This is obviously not early fall coloration.  This condition and appearance is characteristic of maple wilt (Verticillium), a bacterial disease usually fatal to all species of maple, as well as some other species and genera of plants.  The disease affects the conductive tissues pf the plant just under the bark, and a pretty certain diagnosis can be made by cutting a cross section of a young branch, which will display an olive colored ring just under the bark.  I have not done this as yet but I am certain the tree has maple wilt. Occasionally a tree might be saved by applying high doses of nitrogen fertilizer to stimulate growth, but that can kill the tree also.  The disease spreads by root grafts and contamination of healthy trees by pruning tools that have been used on infected trees.  It is a good idea to always sterilize pruning tools with alcohol or bleach after each cut when pruning any diseased tree or shrub.  Keeping a tree healthy through proper fertilizing, watering and pruning is the best way to prevent infection.
    When a plant has succumbed to a disease, the same species should never be planted in its place, as most diseases are specific to a particular host.  If replanting in the same spot that a maple has succumbed to maple wilt, be sure to get the latest information on what other species can be planted that are not susceptible to Verticillium wilt.
    Buddy is by nature a wide-ranging pointer, who loves to run like the wind in tall grass.  Probably more adapted to pheasants and quail than grouse. 

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