Actually, infected roots are slightly enlarged and have a very irregular surface irrespective of the adhering soil. The outer portion of such roots often separates readily from the axial portion, exposing the central cylinder. Aboveground Not all citrus trees having a high citrus nematode population on the roots show aboveground symptoms. Symptom expression may not be noticeable for 5 to 10 years after peak nematode population levels are reached. However, aboveground symptoms, when they finally appear, consist of general symptoms of malnutrition, such as yellowing of leaves, sparse foliage, small, nonuniform fruit, and defoliated branch ends.
Infected trees shed more leaves than do uninfected trees.
This is particularly true during periods of environmental stress, such as those occurring in Florida during the low-rainfall season in the spring. The degree of decline may vary considerably from tree to tree. Generally, the correlation between nematode populations and decline symptoms is negative. Large populations of the parasite build up on the extensive roots of growing trees. These populations decrease rapidly as roots are damaged, become decayed, and decrease in number.