Published Date: 2007-11-10 18:00:12
Subject: PRO/PL> Anthracnose & stem-end rot, mango - Australia (NT)
Archive Number: 20071110.3650
ANTHRACNOSE AND STEM-END ROT, MANGO - AUSTRALIA (NORTHERN TERRITORY)
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: 8 Nov 2007
Source: Australian Broadcasting Corporation Rural [edited]
Rotten mangoes cause headaches for NT growers
Melbourne fruit wholesalers are being forced to reject and even dump
thousands of rotten mangoes from the Northern Territory. Heavy rain
and humidity near Darwin has caused ripening mangoes to break out
with the fungal disease anthracnose and stem-end rot, up to a week
after they have been picked.
Kire Karevski from HolmanFresh says much of the produce is being
down-graded, with some of it being thrown out.
"Initially we thought it might be isolated, but now as the season's
progressed over the last couple of weeks, the problems have really
started to show up and they've become more and more serious," he
says. "We're getting in very high percentages, we're getting up
around the 30 to 40 percent mark now with anthracnose through it.
There's not a lot you can do. You either sell it very quickly and
cheaply or you dump it".
[Anthracnose is the most important mango disease and is widespread.
It is caused by the fungi _Colletotrichum gloeosporioides_ (current
name _Glomerella cingulata_) or _C. acutatum_. Flower blight, fruit
rot, twig dieback and leaf spots are among the symptoms of this
disease. Anthracnose can completely destroy the flowers and cause
extensive dead areas on leaves greatly reducing yield. The fungus
apparently invades the skin of young fruit and remains in a latent
state until fruit ripening begins. Ripe fruit, either before or after
picking, can then develop prominent dark-brown to black spots. Fruit
infection commonly occurs and can result in extensive rotting.
The fungi have a long saprophytic survival ability on dead twigs and
fallen leaves and these are the main sources of inoculum. Spores wash
along in water droplets falling from infected twigs and panicles
above the fruit. Anthracnose is usually more serious when rain and
heavy dews are frequent during the period from the onset of flowering
until fruit are about half size. Control of anthracnose centers on a
diligent fungicide programme. More Indo-Chinese/Philippine type mango
varieties show levels of resistance to anthracnose than Indian type varieties.
_Colletotrichum_ species have been reported causing anthracnose-like
symptoms on many crop species .
Stem end rot is mainly a postharvest disease and can be caused by
several fungal species. In Australia, _Dothiorella dominicana_ has
been reported to be the predominant cause, with _Lasiodiplodia
theobromae_ and _Phomopsis mangiferae_ also being important species
at a few sites. A dark rot develops from the stem end as fruit ripen
after harvest. In fruit from drier areas, stem end rot may be more
serious than anthracnose. Disease management includes avoiding
harvesting of immature fruit and postharvest treatments with
chemicals or hot water.
Anthracnose leaf symptoms:
Anthracnose fruit symptoms:
Stem end rot:
Anthracnose fact sheet with pictures:
Anthracnose disease information:
Information on mango diseases including anthracnose:
Anthracnose and stem end rot in Australia, information and control:
_C. gloeosporioides_ taxonomy:
_G. cingulata_ taxonomy and synonyms:
Causes of stem end rot in Australia:
_D. dominicana_ taxonomy:
_L. theobromae_ taxonomy:
_P. mangiferae_ taxonomy:
Mango disease research in NT:
List of mango diseases and pathogens: