Crown symptoms

These are some of the symptoms you might see on the crown of the coconut. Click on the possible causes of the symptoms to find out more.

Symptom

 

Possible cause

C bogia disease

Coconut palms with dropping fronds or spear leaf only (© Luigi Guarino, Global Crop Diversity Trust)
 

Bogia coconut syndrome (BCS)

ccoconut phyto 1_opt

Outer parts of the frond turning yellow and curling over. The older fronds may have turned brown and be drooped towards the stem (© Northern Australia Quarantine Strategy, Department of Agriculture and Water Resources, Australia)
 

Bogia coconut syndrome (BCS)

CFD palm _opt copy

Yellowed and broken mid-section with new green fronds emerging from the top of the crown (© Jean-Pierre LabouisseCIRAD
  Coconut foliar decay

foliar_decay malayan dwarf _opt copy

Malayan dwarf seedling showing yellowed mid-section and dropping fronds (© John RandlesWaite Agricultural Research Institute)
  Coconut foliar decay

seedling damage

Malayan Dwarf seedling with burnt-looking leaflet damage (© PestNet)
 

Coconut hispine beetle

Additional symptoms of coconut hispine beetle include: 

  • Red-brown narrow strips of feeding damage on the unopened spear leaf, parallel to the midrib.
  • Enlarged strips or streaks when the leaf unfolds that look blotchy and grey-brown.
  • Leaves may look burnt when symptoms are severe.
  • Malayan Dwarf varieties are showing more symptoms compared to others.

CRB crown damage_opt

Few to many fronds showing wedge or v-shapes (© Pacific Biosecurity)
 

Coconut rhinoceros beetle -Orcytes

Additional symptoms of coconut rhinoceros beetle include: 

  • Boring in young fronds that are yet to open.
  • Bored holes in the base of the frond midrib (10-50 cm from the base).
  • Excreted plant tissue and frass at the entrance of bored holes.
  • Palms of a young age of 1-3 years more severely affected.
  • Healthy palms older than 1-3 years, mature and tall (20-30 m), flower or fruit bearing, may have reduced strength and growth of the crown.
  • Secondary infections visible at the bored holes.

sexava defoliation_opt copy

Coconut palms showing defoliated crowns (© Richard MarkhamACIAR)
 

Coconut sexava treehopper

Additional symptoms of coconut sexava treehopper include: 

  • Population outbreaks in treehoppers.
  • Younger fronds defoliated first. 
  • Signs of damaged fruit and flowers.
  • Reduced fruit yields with only 40% defoliation.

aspidiotus_rigidus plantation damage_opt

A coconut plantation showing many yellowed palms. The top of the palm may still show green fronds (© Merle Shepard and Gerald CarnerClemson University)
 

Coconut scale

This symptom may be confused with lethal yellowing 

Ganoderma crown_copy

Crown of a palm showing wilted fronds and dead lower leaves (© Monica Elliott, USDA APHIS ITP, Bugwood.org)
  Ganoderma butt rot

LY fronds hanging down and crown missing_opt

Dead coconut palms with yellow fronds at the top and dead brown fronds hanging down (L) and without the crown (R) (© Nigel A. HarrisonUniversity of Florida)
 

Lethal yellowing

Additional symptoms of lethal yellowing include: 

  • Blackening and rotting of the inflorescences (flower clusters).
  • Death of the emerging spear leaf.
  • Death of the growing point of the palm.

Malayan dwarf symptoms_opt

Red-greyish brown leaves showing throughout green healthy leaves (Malayan Dwarf variety) (© Nigel A. HarrisonUniversity of Florida)
 

Lethal yellowing

Additional symptoms of lethal yellowing include: 

  • Blackening and rotting of the inflorescences (flower clusters).
  • Fronds die and hang down.
  • Death of the emerging spear leaf.
  • Death of the growing point of the palm occurs next.
  • The crown falls, leaving a dead trunk only, sticking up like a telegraph pole.

RP Mite damage to palm_opt

Lower third of a coconut palm with most of the leaflets yellowed and dead (browning at the frond tips) (© Jorge PeñaUniversity of Florida)
  Red palm mite

Red_Ring_External_Symptoms_opt-2

Coconut palm with bronzed, dead fronds and broken fronds hanging down towards the ground (© Monica L. ElliottUniversity of Florida)
  Red ring nematode

Tinangaja crown

Coconut palm with a thin and battered crown (© George Wall, formerly CALS/AES University of Guam)
  Tinangaja - also look for a tapered trunk
Previous page: Bud / flower symptoms Next page: Nut symptoms