Which dogwood trees are most
likely to contract anthracnose?
To determine which dogwoods are likely to get anthracnose, Tennessee Agricultural
Experiment Station (TAES) researchers developed several different experiments
at research plots in Tennessee, North Carolina, and Virginia. A research
plot, in this instance, was a group of 10 trees with a trunk diameter of
1 inch at 4 feet above the ground. If you plant a flower bed in your yard
and decide to experiment with growing different flowers in that bed, you
have developed a research plot.
TAES researchers found the trees more likely to contract anthracnose are
those:
- Growing close to streams
In the Great Smoky Mountains National Park, researchers studied trees growing
at different distances from water. They noticed that trees within 20 meters
of streams caught the disease much more quickly than those between 20 and
50 meters of streams. Trees farther than 200 meters from the stream were
the last to catch the disease
- At elevations above 460 meters
In the Cherokee National Forest they studied trees at different elevations.
Epidemics were much worse in trees growing at elevations above than 460
meters than in trees growing at elevations below 460 meters.
- Growing on north-facing slopes or on the north sides of houses
In the Great Smoky Mountains National Park, anthracnose was more severe
in trees on slopes facing north and less severe in those facing south. Researchers
found that leaves on the north side of trees were slower to dry than those
on the tree's south side. They determined that the longer the leaf stays
wet, the greater the chance of the tree contracting anthracnose.
- Growing in full shade
Along the Blue Ridge Parkway, trees in full shade were much more likely
to contract the disease than those in full sun.
