Lab #1 Non-infectious Diseases
Chemical Damage
Salt Damage on Harwoods:
Salt Damage on basswood: Note necrosis and chlorosis at edge of leaves.
Salt Damage on oak.
Salt Damage on maple.
Salt damage on ginkgo
Salt damage on elm
Salt Damage on pine: Tips of needles are affected, first turning chlorotic then necrotic.
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Chemical damage on maple caused by a spray containing oil. Note damage occurs wherever the oil hit the leaves.
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Herbicide Damage - This herbicide caused curling of leaf edges as well as the "Shepard's crook" (branch tip curling or epinasty) and killed the tree.
Herbicide Damage on aspen - low concentrations of herbicides can cause distorted growth and odd looking leaves.
Herbicide damage on spruce causing the growing tips to be distorted.
Not herbicide damage - Although these symptoms look like herbicide damage, this is caused by a fungus and it is called aspen twig blight. After infection, the tips turn black and become curled.
An unknown for you to consider - What do you think caused these symptoms?
This oak tree had unusual symptoms. What may have caused this damage?