My Citrus Tree Is Dying

Identification

• Citrus trees are susceptible to the Phytophthora root rot fungal disease caused by Phytophthora citrophthora and P. parasitica. The disease is potentially lethal if not controlled in time. Phytophthora root rot is more common in trees growing in heavy or poorly drained soil, according to the University of California's Integrated Pest Management Program.

Symptoms

• Infected citrus trees start to die slowly. The fungus infects the roots and starts to rot them. This affects the flow of water and nutrients throughout the tree. Foliage takes on a dull green to yellow color and falls. The trees produce poorly and all reserved energy is depleted.

Management

• Use resistant species and plant trees in well-drained soil. Avoid overwatering tree or watering crown of tree directly. Do not cover the graft union with soil. If disease is confirmed, remove soil all the way down to top of main roots and let the tissues dry. Chemical control options include foliar applications of fosetyl-al.