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Published Date: 2008-02-29 23:50:00
Subject: PRO/PL> Fungal diseases, mango - Australia, Pakistan
Archive Number: 20080229.0832

FUNGAL DISEASES, MANGO - AUSTRALIA, PAKISTAN
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[1] Malformation disease - Australia (Northern Territory) 1st report
[2] Quick decline - Pakistan (Punjab)

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[1] Malformation disease - Australia (Northern Territory) 1st report
Date: Mon 25 Feb 2008
Source: ABC News (Australian Broadcasting Corporation), Rural News
Northern Territory [edited]
<http://www.abc.net.au/rural/nt/content/200802/s2171827.htm>

Mango industry on high alert
-----------------------------
The mango industry is on high alert, following the finding of a
malformation disease at a research farm at Coastal Plains [CPRF],
just south of Darwin. It's the 1st time the fungal disease has been
found on a tree in Australia. The malformation, which is transmitted
by a tiny mite, distorts the flowers and reduces yields.

The president of the Australian Mango Association, Peter Delis, says
he still doesn't know what impact the disease will have on the
industry "The belief is that it's not going to be a problem,
particularly because it's only been found on one tree. We've done a
survey in the surrounding one-kilometer radius and didn't find it
anywhere else. That tree and surrounding trees have been removed, so
for all intents and purposes the industry's working towards declaring
this thing eradicated and as part of that process we're looking at
beginning a surveillance program."

Northern Territory mango growers were notified about the disease at a
post-harvest forum held on Saturday [23 Feb 2008]. President of the
Northern Territory Mango Association, Peter Marks, says growers were
keen to learn more about the malformation finding. "I don't think we
have anything in particular to fear about, it's not one of those
types of things that are wind borne, that can necessarily be carted
around that easy. It's quite localised on individual trees and it
doesn't even appear, when they did their survey, that it spread to the
trees surrounding it."

[Byline: Kendall Jackson]

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[2] Quick decline - Pakistan (Punjab)
Date: Fri 29 Feb 2008
Source: Pakissan [edited]
<http://www.pakissan.com/english/issues/mango.orchard.at.stake.shtml>

Mango orchards at stake
-----------------------
A strong threat of the lethal disease quick decline to the mango
orchards has established in South Punjab. Thousands of mango trees
were observed last year [2007] showing black coloured stink liquid at
the collar portion of the stem, wilting, and then finally dying of
the plants within a few days and the injured roots have been found as
primary site of infection spread.

Neither a complete disease diagnostic set up could be established in
Multan to streamline strategy against quick decline, nor a single
research specialist on mango is available in the country to protect
the 3rd biggest crop of the country, said the mango growers.

Thousands of mango trees have been cut down in past years due to
severe attack of disease. Not a single commercial variety has been
found resistant to this disease. The problem is more common in the
canal-irrigated orchards and more severe where Shishum trees are
planted as windbreaks. This disease was observed for the 1st time in
Shishum trees [_Dalbergia sissoo_, Indian rosewood] in 1995 and it
started destruction of the species but no precautionary measures were
adopted and the disease rapidly traveled through all the Punjab and
eliminated Shishum planted along the roads.

The most lethal attack of quick decline is appearing everywhere in
the Punjab Province mango orchards and is a rising threat to the
industry. The PMDMC (Punjab Mango Diseases and Management Committee)
visited at least 400 orchards and found critical symptoms of the
disease. The government has fixed a 3-year target to root out the
disease.

[Byline: Nadeem Shah]

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[Mango malformation disease (MMD) is a fungal disease of mangoes
caused by several species of _Fusarium_, some yet to be described.
Mango is the only known host, and it is one of the most important
diseases of this crop. The disease was first reported in India, but
has subsequently been found in many other regions. However, fungal
species contributing to MMD may possibly vary in different areas.
Infected vegetative shoots are misshapen with shortened internodes
and small stubby leaves. Inflorescences are shorter, thicker, have
crowded branches, and do not bear fruit. Vegetative malformation is
most serious on seedlings and small nursery plants, although it can
also seriously affect mature trees. Symptoms are thought to be a
result of hormonal imbalances induced by the fungi. The epidemiology
of disease is poorly understood. It spreads very slowly, but if left
unchecked, it can severely reduce yields. The main method of spread
to new areas is through infected vegetative planting material, there
is no evidence of spread with fruits or seeds. It is often associated
with the bud mite _Aceria mangiferae_, but the mites have been shown
to spread the disease only within a tree, not between trees. Disease
management relies mainly on phytosanitary measures, removal/exclusion
of inoculum, and the use of clean planting material.

Australia was thought to be free of MMD. However, a recent report by
the Northern Territory Department of Primary Industries, Fisheries
and Mines (NT DPIFM) states that in November 2007 symptoms were
detected on 10 trees in a finalised research trial containing about
2000 trees at CPRF. The symptomatic trees were sampled, and so far
_Fusarium_ species were confirmed in one tree by molecular diagnostic
methods while the results for the other trees are still pending (S.
Smith, NT DPIFM, personal communication). The station was quarantined
and locked down to prevent any spread of the disease and extensive
surveys on neighbouring commercial properties did not detect any
trees with MMD symptoms. All mango trees on CPRF have been removed
for burning.

Quick (sudden) decline of mango is caused by the fungus
_Lasiodiplodia theobromae_. The pathogen can also affect other crops,
for example grapevine and citrus. According to the report above, it
is also thought responsible for the destruction of the Shishum trees,
which could have served as pathogen reservoirs. The disease has also
been reported from other mango growing areas, for example in India
and Oman. It is of great economic importance since the plants die
within a very short time. Symptoms include wilting, drying of
branches, foul-smelling exudates, 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.

Maps
Australia:
<http://www.ga.gov.au/image_cache/GA4073.jpg> and
<http://healthmap.org/promed?v=-25.7,134.5,4>
Northern Territory:
<http://www.ozhorizons.com.au/nt/map.gif>
Pakistan:
<http://www.lib.utexas.edu/maps/middle_east_and_asia/pakistan_pol_2002.jpg>
and
<http://healthmap.org/promed?v=30,69.4,5>

Pictures
Fungal malformation of mango shoots and flowers:
<http://www.rbgsyd.nsw.gov.au/__data/assets/image/51698/MangoMalformation.jpg>
and
<http://www.ikisan.com/Images/man_dm_malfmn.jpg>
Comparison of _F. subglutinans_ affected and healthy mango flowers:
<http://www.apsnet.org/online/Archive/1999/IW00012.htm>

Links
Additional mango malformation news stories:
<http://www.abc.net.au/rural/news/content/200802/s2171587.htm> and
<http://www.abc.net.au/rural/nt/content/200802/s2170219.htm>
Background on mango malformation disease in NT:
<http://www.nt.gov.au/dpifm/Content/File/p/Plant_Pest/mango_malformation.pdf>
Information on MMD and control measures:
<http://www.hindu.com/seta/2004/08/19/stories/2004081901061600.htm>
Fungal species associated with mango malformation:
<http://www.mycologia.org/cgi/content/full/94/4/722>
Information on mango quick decline:
<http://www.pakistan.gov.pk/divisions/food-division/media/Brief%20on%20Mango%20Die%20Back.pdf>
Taxonomy of all fungi via:
<http://www.indexfungorum.org/Names/Names.asp>
NT DPIFM:
<http://www.nt.gov.au/dpifm>
Background on mango:
<http://www.hort.purdue.edu/newcrop/morton/mango_ars.html>. - Mod.DHA]

See Also