According to the University of California Agriculture and Natural Resources, the diseases that most commonly affect lemon trees are root rot, mold, bacterial blast, nematodes and blight. There are two variations of root rot that affect lemon trees.Continue Reading
Amillaria root rot and phytophthora root rot are both common diseases that are identified by damage to the root system and the leaves of the lemon tree. The leaves may become yellow or fall off the tree when root rot is present. Root rot can be a symptom of another type of disease or a nematode infestation. The citrus nematode may cause trees to produce smaller or less fruit than expected. The University of California states that citrus nematodes are typically identified by official testing after other diseases and pests have been eliminated as possibilities.
Sooty mold is just one type of mold that can affect lemon trees and is the result of pest infections. The mold appears black or dark and is present on leaves. Anthracnose is a less common disease that causes dark spots to develop on lemons and leaves to die. Dark spots may also be visible on the twigs or trunk of the tree when anthracnose is present. Dothiorella blight is a condition that may occur when lemon trees aren't watered properly, are overexposed to sunlight or are infected by dothiorella canker spores.Learn more about Trees & Bushes