This document discusses several date palm diseases, including their symptoms, causes, and management strategies. Bayoud disease is caused by a fungus and spreads through soil, affecting Morocco and Algeria. Dothiorella causes browning of palm tissues and fruiting bodies. Pink rot is caused by Gliocladium vermoeseni fungus and enters through wounds. Graphiola leaf spot causes small leaf spots and is controlled with fungicides. Lethal yellowing is caused by a phytoplasma transmitted by planthoppers and can be reduced with antibiotic injections.

2. Date Palm Diseases
A
Lecture To ToT trainees ( FFS)
By
Mr. Allah Dad Khan
Provincial Coordinator IPM KPK
MINFAL Pakistan

4. 
Symptoms of Bayoud disease on date palm

Symptoms
 Leaflets of mature leaves becoming chlorotic at the base on one side; leaf death progressively to the
leaf tip; brown or white lesions on underside of leaves
 Cause
 Fungus
 Comments
 Soil-borne disease; currently restricted to Morocco and Algeria where it can be devastating; the
popularity of susceptible cultivars means it has a massive potential to continue to spread
 Management
 Cultural control is not recommended for the control of the disease as conditions which favor high yield
of dates also favors growth of the fungus; if disease is confirmed then infected tree should be uprooted
and burned to prevent spread; soil should be treated with methyl bromide or chloropicrin and the area
closed off

5.  Dothiorella causes a severe browning of all the cortical tissues
including the xylem elements giving a broad band of dark tissue
(figure 2). If the samples are retained in a moist cool place, they will
often form fruiting bodies (pycnidia) that erupt through the
epidermis of the rachis (figure 3). Microscopic examination of the
fruiting bodies and spores will confirm the diagnosis.

6.  Symptoms
 Dark brown-black, hard lesions on leaves; foliage with scorched
appearance
 Cause Fungus
 Comments Palms may recover from disease; fungi can enter through
pruning wounds
 Management Prune out infected fronds, leaf bases and
inflorescenses and burn the material immediately; pruning wounds
should be protected by spraying with Bordeaux mixture

7. The pink rot disease of palms is perhaps the most ubiquitous palm disease in
the landscape. It is caused by the fungus Gliocladium vermoeseni,
(Pennicillium vermoeseni) a member of the fungi imperfecti. The perfect
stage of the fungus is not known. The biology of the pink rot fungus is
amazing in that it can produce billions of spores while growing on a single
plant. Thus its spores are always present where palms are grown so there is
no way to avoid it. The fungus is a weak pathogen in that it requires a wound
or other plant stress factors that enable it to infect.

8.  Symptoms
 Death of suckers either while still attached to mother
or after planting
 Cause
 Fungus
 Comments
 Fungus usually enters through cutting or pruning
wounds
 Management
 Disinfect all tools and equipment regularly; protect
pruning wounds and cuts with Bordeaux mixture or
other appropriate copper based fungicides


9. 
Graphiola leaf spot symptoms on date palm frond

Symptoms
 Small spots on both sides of leaves; yellow spore masses on leaves; black crater-like
lesions on leaves
 Cause
 Fungus
 Comments
 Disease emergence favored by high humidity
 Management
 Infected leaves should be pruned out and destroyed; disease can be controlled by sprays
of Bordeaux mixture or other appropriate broad spectrum fungicide

10.  The disease is called diamond scale because of the diamond shaped
ascothecia or ascus bearing structures that form on the leaves of
affected palms. Contrary to common belief, this is not a “scale”
insect, but the fruiting body of the ascomycete fungus mentioned
above. The diamond shaped structures hold the sexual spores of
the fungus. The asexual stage of the fungus (anamorph) has not
been identified. Since not all the spore stages of the fungus are
know, an accurate life history of the organism is impossible to
discern.

11. 
Symptoms of lethal yellowing on date palm

Symptoms
 Fronds drying out and turning gray-brown; growing tip rotting and turning into a slimy
mass with foul smell; crown collapses from trunk leaving a naked trunk
 Cause
 Phytoplasma
 Comments
 Disease is transmitted by planthoppers
 Management
 Disease severity can be reducced by injecting the antibiotic oxytetracycline HCl into the
trunk; antibiotics can also be administered as a protective measure if the disease is
known to be in the area; control of the disease long term relies on planting resistant or
tolerant varieties