Diseases

Avocado Phytophthora Root Rot

Persea americana Mill.

The most serious disease of avocado, caused by the oomycete Phytophthora cinnamomi. The pathogen infects feeder roots, leading to their decay and the subsequent death of the tree's aerial parts.

In the reference 6 varieties crop Avocado, where this is mentioned in the description.

The causal agent of Phytophthora root rot is the soil-borne oomycete Phytophthora cinnamomi, an aggressive pathogen with an extremely wide host range. There are no classic races identified within the pathogen population, so researchers classify them by clonal lineages, virulence, and temperature adaptations.

The disease primarily affects small feeder roots, which turn black and become brittle, disrupting the uptake of water and nutrients. Secondary symptoms on the aerial parts include leaf chlorosis, tip necrosis, premature leaf drop, canopy thinning, and gradual twig dieback.

There are no specific standardized resistance genes for avocado. Breeding is directed toward finding rootstocks with partial field resistance, such as Duke-7, G6, or Dusa, which are capable of limiting pathogen development in the root system through mechanisms of tyloses formation in the vessels.

General information about the subject — on the page Late blight.

Sources8

Varieties of Avocado mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.