Trees infected with the viroid often show no symptoms other than a reduction in yield, (by 30% or more).

Symptoms in more serious infections include depressed longitudinal streaks of yellow in the fruit.

The amount (titre) of viroid particles present in avocado trees varies a great deal.

Infected but symptomless trees have a higher concentration of viroid particles than those showing symptoms.

Symptomless trees also represent a greater danger in terms of spread of the viroid.