Symptoms
- Symptoms can be found year round, but are most easily seen from September through March
- The disease affects all parts of the tree canopy - leaves, twigs and fruit
-
As the disease progresses, it will cause the whole tree to decline
Leaf Symptoms
- Leaf symptoms include blotchy mottle, yellow veins, vein corking or green islands
- Yellow veins, vein corking or green islands are not diagnostic alone
- Blotchy mottle is the best diagnostic leaf symptom of greening
- Blotchy mottle: a random pattern of yellowing (chlorosis) on leaves that is not the same on the right and left sides of the leaf
- Yellow veins can be confused with other diseases (e.g. foot rot) or damage (e.g. broken or girdled limb)
Pen Test for Leaves
- A simple procedure to determine if symptoms are the same on both halves of a leaf
- Draw two circles on opposite halves of the leaf
- Is the pattern the same in both circles?
- Different patterns indicate potential greening if other problems have been ruled out
- Fruit external appearance may be lopsided, misshapen or small green fruit
- The fruit would taste salty and bitter
- The internal appearance may have aborted seeds, yellow stain beneath the calyx button and/or a curved central core
- Yellow shoots
- Twig dieback
- Stunting
- Off-season bloom
- Overall tree decline
Nutrient Deficiency |
Greening |
Fruit Symptoms
 |
Tree Appearance
 |
 |