| Disease |
Symptoms |
Pathogen/Cause |
Management |
| Decline |
Stunted growth and dieback occurs. Young foliage
turns gray-green or bronze and finally straw color. Old leaves
fall prematurely. Middle or top branches die. Sunken cankers
form at the soil line or on branches in the crotches where dead
leaves accumulate. Wood under the sunken canker is blackened. |
Attack by various fungi and nematodes adds to
damage from winter injury and stress on plants especially those
in poorly drained sites. |
Protect plants from winter injury and other stresses.
Prune dead branches well below cankered areas. Remove dead leaves
accumulated among the branches. |
| Leaf spot |
Straw-yellow leaves are dotted with small black
fungal fruiting structures. |
Macrophoma candollei |
Only leaves weakened by winter injury are infected.
Protect plants from wind, salt spray, and salt runoff. |
| Leaf burn |
Leaf tips and margins yellow and redden as leaves
fall prematurely. |
Water stress and low temperature |
Protect shrubs from drought and drying winds
in the autumn and winter. |
| Nematodes |
Growth is stunted, leaves have a bronzed appearance,
and the shrub is in decline. Small roots have small brown dead
areas that enlarge to engulf the entire root ends. |
Pratylenchus |
There are no adequate controls once the plant
is infected. If a plant is removed, do not replace it with a
nematode-susceptible plant unless the site is thoroughly fumigated
and aerated first. |
