Avocado trees are very susceptible to root rot, which is caused by the soil-borne fungus Phytophthora cinnamomi (root rot). This is basically the issue of plants rotting. Controlling this disease is the highest priority for avocado growers. Farmers therefore should be informed of the signs and symptoms of this disease it is ever-present and requires constant attention. Without root rot management the tree will lack an adequate root system and can’t perform.
Effective root rot control comes from an integrated approach that includes:
• Disease free nursery trees
• Using more tolerant root-stocks
• Good drainage which includes the use of tree mounds
• Mulching and good soil health
• Appropriate soil moisture management
• Chemical treatment
• Good nutritional practices including sufficient calcium
• Suitable soil ph.
However, in case your tree is already affected there are chemical ways to control this incidence .
Phosphonate fungicide is the best chemical root rot treatment, both as a regular preventative treatment and to cure the disease. It is essential that you maintain an annual, or in some cases biannual, treatment with phosphonate.