Avocado Tree Root Rot Symptoms

  • Apr 15, 2013

Phytophthora cinnamomi, the causal agent of avocado phytophthora root rot, attacks the feeder roots, which can result in death of the avocado tree. Although the disease has been studied for more than 60 years, definitive control measures have not been found and losses continue to mount.

However, many root rot control strategies have been discovered which can reduce the impact of avocado root rot. Integrated management of avocado root rot is key to controlling the disease.

Symptoms of avocado tree root rot

  • The first signs of the disease are observed in the tree canopy — leaves are small, pale green, often wilted with brown tips, and drop readily.
  • Avocado tree shoots die back from the tips, and eventually the tree is reduced to a bare framework of dying branches.
  • Avocado tree death may take from a few months to several years, depending on soil characteristics, cultural practices and environmental conditions.
  • Small feeder roots on diseased avocado trees may be absent in the advanced stages of decline. When present, they are usually black, brittle and decayed, in contrast to healthy creamy-white feeder roots.

If you have avocado trees in your grove with the above symptoms, using integrated cultural management practices can help you treat and manage root rot disease outbreaks.