Avocado Pests and Diseases: Protecting Your Trees

Introduction

Avocado trees add value to home gardens and orchards, but they face a range of pests and diseases. Early detection and good cultural care are the main defenses.

Common Pests

Insects and mites to watch

• Avocado thrips can scar young fruit and leaves, especially in warm, dry summers.
• Scale insects (soft and armored) show up as bumps on stems and leaves and can cause honeydew and sooty mold.
• Spider mites cause bronzing on leaves, stippling and leaf drop in hot, dry conditions.
• Root weevils and grubs attack roots and can weaken trees.

Prevention and scouting

Regular leaf and fruit checks; use sticky cards, inspect undersides of leaves, look for honeydew or distorted growth.

Common Diseases

Phytophthora root rot

Causes root decay, wilting, and tree decline; favored by poorly drained soils and overwatering.

Avocado sunblotch viroid

Causes streaks on fruit and shoots and stunted growth; management focuses on sanitation and removing infected wood.

Leaf spot and anthracnose

Dark spots on leaves and fruit; improve air circulation and avoid overhead watering.

Other potential issues

Bacterial canker or stigma blights occasionally appear; diagnosis by a local extension service is recommended.

Prevention and Care

• Plant in well-drained soil; avoid waterlogged conditions.
• Mulch to improve moisture retention and soil health.
• Provide good air flow through pruning; avoid dense canopies.
• Water deeply but infrequently to encourage deep roots.
• Monitor regularly and remove infected material promptly.

Management Options

• For pests: horticultural oils, insecticidal soaps, and, when needed, targeted pesticides following local guidelines; beneficial insects can help.
• For diseases: improve drainage, avoid overwatering, rotate irrigation if possible, and consult local extension for resistant rootstocks or approved fungicides.

Bottom Line

A healthy avocado tree starts with good drainage, careful monitoring, and timely cultural care. Early detection of pests and diseases makes management easier and protects fruit quality.