Phytophthora root and crown rot—Phytophthora spp.
Trees or plants infected with Phytophthora often wilt and die rapidly with the first warm weather of
the season. Leaves may turn dull green, yellow, or in some cases red or purplish. Symptoms may develop
first on one branch or stem then spread to the rest of the tree or plant. Darkened areas develop in the
bark around the crown and upper roots. Gum or dark sap may ooze from the margins of the diseased trunk
area. Reddish brown streaks or zones can be seen in the inner bark and outer layer of wood.
Identification
Solutions
The key factor in reducing the threat of root and crown rot is good water
management. Good soil drainage
is best provided before
planting. Plant certified nursery stock on mounds made by working up the soil.
Never cover the graft union with soil and do not water the crown area directly. If you suspect crown
rot, carefully cut away affected bark at the soil line. Trees can sometimes be saved by removing soil
from the base of the tree down to the tops of the main roots and allowing the crown tissue to dry out.
For more information, see the Phytophthora
Root and Crown Rot Pest Note. |  Symptoms
of Phytophthora infected plant
 Gumming
and reddening of wood
|
