13. Citrus Canker
Citrus canker is a serious bacterial disease of citrus trees including
grapefruit, lemons, limes and oranges. It reduces the growth of new fruit and
spoils healthy fruit. Outbreaks of this disease have been eradicated from
Queensland and the Northern Territory at great cost to industry and growers.
The disease attacks the leaves, twigs and fruit of citrus trees. It causes the
leaves to drop and fruit to fall to the ground before it ripens. People may also
contribute to disease spread by moving infected plants or plant parts
22. Citrus greening
Identification tip:
Mottling and yellowing that
cross leaf veins help to
distinguish citrus greening
(Huanglongbing), an exotic
tree-killing bacterium. When
zinc deficiency is the cause,
discoloring occurs between
distinctly greener veins.
Report to agricultural
officials any finding citrus
greening disease
26. Phytophthora gummosis
Identification tip
:Phytophthora
gummosis is the most
common cause of
profuse dark exudate
from bark. Several other
limb, trunk, and root
diseases cause oozing
bark and can stunt and
sometimes kill trees.