Palm Diseases – Ganoderma

Palm diseases in north and central Florida

 Ganoderma
the dreaded “butt rot” of palms

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This palm has been killed by Ganoderma. Note the conks on the lower trunk in this photo and the photo below.

Ganoderma, caused by the fungus Ganoderma zonatum, is an infrequent but devastating palm problem. If your palm gets Ganoderma, it will die and you will not be able to safely plant another palm in that location in your landscape. Researchers are not sure how palms become infected. They believe the fungus is transmitted through wounds to the roots made during transplanting, wounds to the lower trunk when pruning off boots, spike wounds made by climbing with spikes or even possibly wounds from continued weed whacker damage at the

Ganoderma zonatum is in the same family as decay fungi that cause internal decay in hardwood trees (Ganoderma applanatum and Ganoderma lucidum) but it is not the same pathogen and will not affect hardwood trees. The disease decays the lower 4 or 5 feet of the palm trunk. It is soil borne but not a root disease. All palms are susceptible to Ganoderma infection.

The symptoms are progressive leaf death from the bottom of the crown. Finally the newest frond, the spear, dies. Often, but not always, a fruiting body (a conk) appears somewhere in the lower part of the trunk. This conk allows for easy confirmation of the disease. This fruiting body drops millions of spores that can infect other palms.

So it is a good idea to remove the conks as soon as they appear. And then remove the dead or dying tree as soon as possible. The lower part of the trunk should be placed in a landfill and not used for mulch. The upper part of the infected palm can be used for mulch.

For a complete brochure on Ganoderma in palms prepared by University of Florida researchers Dr. Monica Elliott and Dr. Timothy Broschat, click here. That article can be downloaded from the site as a PDF file.

This palm is infected with Ganoderma. The lower fronds are gradually dying and the center spear, the newest leaf, is smaller. Conks (shown in the next photo below) were found on the lower trunk

This palm is infected with Ganoderma. The lower fronds are gradually dying and the center spear, the newest leaf, is smaller. Conks (shown in the next photo below) were found on the lower trunk

Trees0010

The fruiting bodies found on the lower trunk of a dying or dead palm confirm the disease, Ganoderma.

 

 

 

 

 

 

 

 

 

 

View of a young, fresh fruiting body on the lower trunk of a dying palm

View of a young, fresh fruiting body on the lower trunk of a dying palm