Published Date: 2009-05-04 10:00:04
Subject: PRO/PL> Gummosis, mango - Bangladesh: (RJ)
Archive Number: 20090504.1669
GUMMOSIS, MANGO - BANGLADESH: (RAJSHAHI)
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Sun 3 May 2009
Source: The Daily Star [edited]
Signs of gummosis worry mango growers
Hundreds of mango trees in the district are being affected with
gummosis disease, locally known as 'athajhora rog', much to the worry
of mango growers. The affected tree starts secretion of gum at a
particular point, this spreads throughout the tree within 3 to 6
months and then the tree dies. It is a fungal disease caused by
_Lasiodiplodia theobromae_, scientists of Regional Horticulture
Research Station, Chapainawabganj [Rajshahi division], said after
observing the disease at different places in the district.
The disease was first detected 2 years ago in several mango trees of
one of the largest mango orchards in the district. The scientists
came to know that the disease first spread into the mango orchard
from nearby shishu trees [_Dalbergia sissoo_, Indian rosewood] that
had been infected with the disease. Several shishu trees also died of
The disease, which normally spreads from November to March, has also
affected some other orchards in the district, sources said, adding
that 100 to 150 year old trees are also dying of this disease.
If the disease could be detected at initial stages, the trees could
be saved using Bordeaux paste [copper based fungicide], said Sharif
Uddin, a scientific officer of the station, adding, "We have saved
some of the infected mango trees in the town. We are trying to find
out the other associate pathogens to come to the final conclusion,"
said Mosharraf Hossain, Plant Pathology Department of the station.
[Byline: Rabiul Hasan]
[Gummosis is one of the symptoms of quick (sudden) decline of mango
caused by the fungus _Lasiodiplodia theobromae_. The pathogen has a
wide host range of more than 280 species and can also affect other
crops, for example grapevine, cocoa and citrus. The 'shishu' trees
mentioned above may have served as pathogen reservoirs, which was
also reported from Pakistan in 2008 (ProMED-mail post no.
20080229.0832). The disease occurs also in other mango growing areas,
for example in India, Pakistan, and Oman. It is of great economic
importance since the trees die within a very short time.
Symptoms include wilting, dieback of branches, gummy exudates,
vascular discolouration, and complete defoliation to give a
'scorched' appearance. It is thought that nutrient deficiencies and
environmental stress factors may increase the susceptibility of the
host. Fungicides may be helpful in disease management if applied
quickly enough, and mango varieties with different levels of
resistance are available.
In mango, _L. theobromae_ is also known to contribute, together with
other fungi, to stem end rot in some growing areas (for example in
Australia), and it may also be a factor in mango decline, a syndrome
including several pathogens.
It appears that the local scientists are screening the affected
mangoes for possible additional pathogens, which may be contributing
to the problems of these trees.
_L. theobromae_ associated symptoms on mango
- gummosis and vascular discolouration:
- branch dieback:
- stem end rot:
_D. sissoo_ tree:
Information on mango quick decline:
Resistance levels of mango varieties:
_L. theobromae_ on grapevine:
_L. theobromae_ on cocoa:
_L. theobromae_ taxonomy and synonyms: